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INDEX
1. MEASURING YOUR REACTION TIME………..………….
2. DIFFUSION, OSMOSIS AND SOLUBILITY………………
3. NEUROPHYSIOLOGY …………………………………….
4. SENSORY PHYSIOLOGY …………………………………
5. MUSCLE PHYSIOLOGY I …………………………………
6. MUSCLE PHYSIOLOGY II ………………………………..
7. BLOOD ………………………………………………………
8. ELECTROCARDIOGRAM ………………………………….
9. BLOOD PRESSURE …………………………………………
10. RESPIRATION …………………………………….………..
11. DIGESTION …………………………………………………
12. REGULATION OF METABOLISM ………………………
13. RENAL PHYSIOLOGY ……………….……………………
14. REPRODUCTION …………………………………………..
15. PEER EVALUATION ………………………………………..
1.
MEASURING YOUR REACTION TIME
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1. MEASURING YOUR REACTION TIME
Objective:
1. Learn about how fast your reaction time is. 2. Learn about calf size and/or gender effect on vertical jump.
Introduction:
A person's reaction time is a measure of how quickly they can respond to a given stimulus. How long it takes to react to a rebound could mean the difference between a win and a loss. How long it takes to react to a stopped vehicle can mean the difference between a safe stop and a collision. It is important to know your limitations before it becomes a life and death situation.
Since an average human reaction time is only a fraction of a second, it would be impossible to measure it directly. By using the known properties of gravity, we can determine how long it takes a person to respond to the dropping of an object by measuring how far the object can fall before it is caught.
From: http://faculty.rpcs.org
Supplies: a. The Subject, a person whose reaction time is about to be measured. b. The Releaser, a person who is to assist the subject. c. Reaction Time Ruler d. Reaction Time Data Sheet e. Chair f. Pencil or Pen g. Calculator Methods: 1. The Subject sits in the chair. 2. The Releaser stands facing the Subject and holds the “release” end of the ruler at eye level, or higher,
between the thumb and first finger of either hand. 3. The Subject positions the thumb and first finger of either hand over the “thumb line” on the ruler.
The space between the Subject’s thumb and first finger should be about 1 inch. 4. When ready, the Subject must tell the releaser to start. 5. Once the subject says to start, the releaser may let go of the ruler at anytime with in the following 10
seconds. At no time during the test period may the Releaser look at the subject. Close your eyes or look away.
6. The Subject must try to catch the ruler between the thumb and first finger as soon as it begins to fall. 7. When the ruler has been caught, the line under the middle of the Subject’s thumbnail should be
estimated. This line represents the number of milliseconds that passed before the ruler was caught. 8. After at least 10 practice drops, the Subject should read aloud each of the following 10 measurements
so the Releaser can write them down on the data sheet. The average of the 10 measurements, (X), is the Subject’s reaction time.
9. Record the age and sex of the Subject on the data sheet.
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10. Now switch positions and repeat. Trial Student 1 Student 2 Student 3 Student 4 Student 5 Student 6 Total Average Questions: 1. Can you improve your reaction time with practice? If so, by what percent? 2. What is your average reaction time? 3. Are you actually measuring two of your reaction times or just one? Are you measuring your lab partner's reaction time as well as your own?
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4. Which kind of people you will expect to have a higher than class average of reaction time? Why?
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2. HOW TO MEASURE YOUR VERTICAL LEAP. GOAL: This exercise is designed to determine the relationship between a student’s calf size and his/her standing vertical jump. 1. Stand with your side to a wall and reach the highest point you can reach (while flat-footed) on the tape measure. Record this height (SE). 2. Move one step back from the first mark (that of your reach). 3. While keeping the trunk straight, bend at the knees and jump upward touching as high on the tape as possible; this is the jump height (JH). Record this height in your table. 4. Repeat this five times. 5. Measure the heights of your standing reach and the highest point you touched on the wall. 6. Subtract your standing reach from the height of the highest point you touched on the wall. The number you find is your vertical jump. 7. Average the five jumps. 8. Record this average on the chalkboard for everyone in the lab. 9. Graph vertical jump height (VJH) versus calf circumference for males and females; make sure to indicate in the graph who’s who. Then use a ruler to draw a best fitting line for both data plots. Calf circumference
Male (M) Female (F)
SE JH VJH
Total Average
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Pre-lab Questions:
1. List the main factors affecting reaction time. 2. List professions that would increase a person’s reaction time. 3. On average, which sex has larger calf circumference, by how much?
HOMEWORK:
Do it your self: http://www.serendip.brynmawr.edu/bb/reaction/reaction.html and bring your collected information.
Go to : http://www.humanbenchmark.com/tests/reactiontime/index.php
Post-Lab questions:
1. Discuss what you think might be possible reasons for these reaction time statistics.
2. Name five professions that would increase one’s ability to perform a better standing calf jump.
2.
DIFFUSION, OSMOSIS AND SOLUBILITY
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2. DIFFUSION, OSMOSIS AND SOLUBILITY
Objective:
1. Learn to identify solute, solvent and solution. 2. Learn about osmosis versus diffusion.
The composition of the human body consists largely of water and water soluble substances.
Movement of substances across cell membranes is heavily influenced by both differences in the concentration of these various molecules (solutes) across the cell membrane and by the permeability of the lipid bilayer to these materials. If you want to understand how the concentration of a particular solute is quantified, as well as how differences in concentration influence passive membrane transport you need to know the difference between solutes, solvent, diffusion and osmosis.
I. Solutions
A. Molecules 1. Solutes are chemicals that are dissolved i.e. salts, sugars in a solution. 2. Solvents are the dissolving agents i.e. water (the largest solvent in our body) 3. A combination of a solvent and a solute that results in the complete surrounding of the
solute molecules by the solvent is known as a solution. B. Polarity
1. Polar molecules are those which share electrons. Due to the sharing, they have a high affinity for one another. Take water for example: the Hydrogen bonds to a very electronegative molecule (a molecule that has a strong attraction for negativity) we know as Oxygen. Now, because the oxygen is more electronegative, the electron that is shared between the two molecules when the bond is made moves toward the oxygen molecule. This creates a partial negative and a partial positive side to the water molecule. This "polar" nature allows water to attract other charged molecules, allowing the molecule to be completely surrounded by water.
2. Non-polar molecules do not share electrons. Their electrons are distributed evenly and so they don't have partially charged regions, making the molecule incapable of being surrounded by water. They are not H2O soluble.
3. When we add detergent to a beaker containing water and oil, the detergent forms a my-cell around the oil creating a molecule with polarity. This allows water to surround the oil giving us a solution. This is why the book says that detergents serve as a bridge when introduced into a polar/non-polar phase.
C. How to make a solution
1. Molarity is a concept chemists made up to compare solutions. a. M = (# of moles of solute) 1 L of solution b. One mole of solute is equal to the solute's molecular weight in grams
II. Membrane Permeability
A. The cell membrane is a semipermeable membrane.
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The membrane is made up of lipids and proteins. This keeps the membrane non-polar and allows it to serve as a barrier to some of the molecules trying to pass into or out of the cell.
B. Other types of membranes are permeable membranes. These membranes allow passage to almost all types of molecules, depending upon the size of the membrane desired.
C. Impermeable membranes do not allow the passage of any molecules. III. Transport across the cell membrane
A. Types of Transport 1. Active transport is the movement of molecules against the concentration gradient, and
thus requires energy. 2. Passive transport is the movement of solutes across the cell membrane from a solution of
higher to a solution of lower solute concentration. 3. Facilitative transport is the movement of solutes from higher to lower concentration with
the help of carrier proteins i.e. glucose with insulin.
B. Diffusion 1. Diffusion is the movement of solutes from a solution of high to a solution of low solute
concentration. 2. Diffusion results from the need for molecules to be at a low energy state. By moving
away from other solute molecules, the molecules decrease the amount of energy being expended into solution.
3. The rate of diffusion is directly proportional to the differences in solute concentration. Particles in solution are usually free to move randomly throughout the solution. As these particles
move, they randomly collide with one another. If there is a difference in the concentration (amount present in the solution) of a particular solute between one region of a solution and another, then there is a tendency for the substance to diffuse from where it is more concentrated to where it is less concentrated. Thus net diffusion occurs “down” a concentration gradient, from an area of high concentration to an area of low concentration, until a state of equilibrium is reached throughout the volume of the solution. At this equilibrium (typically when the concentration is homogeneous), there will be no more net diffusion of solute from one area to another, although random movement of particles will continue.
If such diffusion is unimpeded by the presence of some barrier (e.g., a membrane that is impermeable to the solute), it is referred to as simple diffusion. In the case of cells, solutes that can readily pass through the lipid bilayer of cell membranes (i.e., small uncharged molecules or moderate-sized nonpolar molecules) are transported across cell membranes via simple diffusion. For example, the exchange of gases such as O2 and CO2 across the plasma membrane occurs through simple diffusion.
C. Osmosis
1. Osmosis is the net movement of solvent (Water) across the membrane from an area of lower solute concentration to an area of higher solute concentration.
2. Osmotic Pressure is the ability of a solution to pull in water from a second solution separated by a semi-permeable membrane. The pressure is directly proportional to the solute concentration of the first solution.
IV. Tonicity
A. Solutions 1. A solution is hypotonic to another solution if its concentration of solute is lower than the
second solution.
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2. A solution is hypertonic to a second solution if the solute concentration is higher in the first solution.
3. Solutions are isotonic when the solute concentration is the same on both sides of the membrane.
B. Hydrostatic Pressure Osmotic pressure occurring in the blood stream, which is responsible for the filtering of the blood, and system equilibrium. 1. Hemolysis will occur when red blood cells are in a hypotonic solution. Water from the
solution will diffuse from the solution into the RBC, causing the cell to burst. 2. Crenation is seen when RBC'S are in a hypertonic solution. The water from the RBC will
diffuse from the cell into the solution, the keep the system in equilibrium.
For animation go to:
http://www.wiley.com/legacy/college/boyer/0470003790/animations/membrane_transport/membrane_transport.htm
DEMO before students start experiments: Materials: Alka-seltzer tablet Raisins 2 beakers Water Beaker 1: Fill with water and place the Alka-seltzer tablet in the beaker. This is a visual demonstration of what diffusion is; a solute dissolving in water. Beaker 2: Weigh a raisin. Place it in a beaker filled with water at the beginning of class. At the end of class weigh the raisin. This is a visual demonstration of osmosis; water crossing a semi-permeable membrane across a density gradient.
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Experiments 1) Osmosis and diffusion In this lab, you will perform an experiment which will illustrate diffusion and osmosis. You will be able to determine through your observations that in a mixture of substances some substances will diffuse through a semi-permeable membrane and some will not. Note: Before performing this experiment note that the following solutions or items will be the tools used to indicate the presence of certain substances. 1. Lugol’s solution contains iodine which is an indicator for the presence of starch. Its golden-
brown color turns blue-black indicating a positive reaction to starch. 2. Glucose test strips react quickly to small amounts of glucose. The reacting area is the small
bright yellow rectangle on the very end of the plastic strip. A green color indicates a positive test for glucose. Do not touch the indicator pad with your fingers prior to using.
Procedures: 1. Fill a plastic cup with distilled (DI) water to within ~2 cm of the top. Test the water for the
presence of glucose and note any color change in the glucose test strip. 2. Add approx. 30 drops of Lugol’s solution to the water in the cup and stir. 3. Obtain a piece of dialysis tubing (membrane) approx. 10 cm long and thoroughly wet one end of
the membrane with water from the beaker. By using your thumb and forefinger open the tubing by rubbing it.
4. Tie a knot very tightly close to one end of the tube using string. 5. Using a pasteur pipete fill ½ of the membrane with a 2% starch solution then place a similar
volume of 1% glucose solution into the membrane and then secure the other end by tying another knot.
6. Thoroughly wash the membrane by placing it under running DI water for a few seconds while gently squeezing the membrane to mix its contents. Observe the initial volume of the membrane. Mark the initial water level of the cup then place the membrane into the cup.
7. After 1 hour observe the contents inside the membrane tube and the liquid inside the cup as well as the cup water level once the membrane is removed from the cup. Test the cup water for glucose, compare this test to the initial glucose test.
2) Solubility of compounds in polar and nonpolar solvents Procedures: 1. Pour 2.0 ml of DI water and 2.0 ml of toluene into a test tube. 2. Shake the tube and record your observations in the laboratory report. 3. Using forceps, drop two crystals of potassium permanganate (KmnO4) into the tube. Shake the
tube and record your observations in the laboratory report. 4. Add 1.0 ml of yellow vegetable oil to the tube. Shake the tube and record your observations in
the laboratory report. 5. Add a pinch of laboratory detergent to the tube. Shake the tube and record your observations in
the laboratory report. Place the contents of experiment 2 in the waste container marked “Toluene Waste”
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HOMEWORK 1. What does the tubing represent? 2. What type of transport was occurring in the experiment? 3. Why can starch not pass through the lipid bilayer? 4. Why must fat be emulsified before the body can digest and utilize it? 5. In the human body, what enzyme emulsifies fat or in other words, does what the detergent did in the experiment?
3.
NEUROPHYSIOLOGY
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3. NEUROPHYSIOLOGY
Objective: 1. The purpose of this lab is to test the learning and memory ability of humans and mice Learning can be defined as the ability to change the response to a stimulus with experience. The ability to learn and transmit knowledge through teaching is the basis for the development of human culture and civilization (2). There are different forms of learning, associative learning, which is a conditioned form (Pavlov’s salivation experiment), and instrumental learning, this is learning by trial and error. The learning that we will be experimenting today is instrumental learning. Instrumental learning is a complex form of associative learning in which the subject takes an active role in the learning process. The reward plays a reinforcing role, instilling the learned behavior repeatedly. The ability to show and use a learned response improves with repeated exposure and practice, until the associated memories become more permanent. Learning and memory formation occur in two stages, an initial short term stage which is followed by a long term stage. Each of these stages are associated with an equivalent type of memory. When first exposure to learning, if the reward is not exposed, the memory will dissipate. However, if the subject is continually reinforced with a reward, that short term memory will turn into a long term memory.
Memory, the ability to retain information or to recover information about previous experiences, is a function of the brain. When we remember something, a process takes place in which our brains recover and reconstruct information about things we've done or learned. (http://www.aarp.org).
A) How Memory Works Memory functions through three steps:
• Acquisition • Consolidation • Retrieval
Acquisition. Before you can remember something, you first must learn the information. This is called acquisition. This acquired information is then put into temporary nerve-cell pathways in the brain. These pathways are where you store short-term memory. Consolidation. In order for something to be placed in long-term memory, the nerve pathways have to be strengthened and reinforced. This process, called consolidation, can take weeks or even months. There are several factors that affect whether or not information will be put into long-term memory. For example, you are more likely to retain information if it relates to pre-existing memories or somehow stimulates you emotionally. Also, it doesn't hurt to have a good night's sleep, as this too helps you retain information. Retrieval. When people retrieve information, they are literally "recalling" it from the nerve pathways. The brain reactivates a particular pathway, and information is remembered. This process can be fast or slow, depending on how familiar you are with the information and how well you learned it in the first place.
B) This section explains types of memories and how memory changes.
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Cognition vs. Memory Many studies of brain aging look at a range of cognitive abilities, beyond memory alone. Cognition includes not only remembering and forgetting, but also abstract thinking, reasoning, attention, imagination, insight, and even appreciation of beauty.
Types of Memories (From: http://www.intelihealth.com/IH/ihtIH/WSHW000/31393/31397/347125.html?d=dmtContent) Memory is broken down into two types: short term and long term. Short-term memory, also known as working memory, stores information that you need to remember in the following seconds, minutes or hours. An example would be a telephone message that you are given and must remember until you pass it on. Long-term memory stores information that your brain retains because it is important to you. Basic information remembered includes names of family and friends, your address, as well as information on how to do certain activities and tasks. Long-term memory can be further divided into explicit, implicit and semantic memory.
• Explicit memories are facts that you made a conscious effort to learn and that you can remember at will, for example, the names of state capitals.
• Implicit memory is information you draw on automatically in order to perform actions such as driving a car or riding a bicycle.
• Semantic memories are facts that are so deeply ingrained they require no effort to recall. An example would be the months of the year.
There are large age-related differences with explicit memory, but age has little or no effect on implicit or semantic memory.
Experiment 1:
LEARNING AND MEMORY PROCEDURE (Watermaze)
CAUTION: Handle the mice by their tails, they may bite, especially if agitated. 1. Place the mouse on the platform and allow it to sit there for about 30 seconds, (first run only)
Make sure your platform is always in the same place. Additionally, try to remain in the same relative position during trials because the mouse might be using you as a visual cue.
2. Next, place your mouse in water bath, (always use the same spot to introduce your mouse
into the water maze). Then start your timer.
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3. Allow your mouse to swim until it finds the platform and record the time it took the
mouse to find the platform. Once the mouse reaches the platform allow it to sit there for 30 seconds. If the mouse does not find the platform by 30 seconds, remove the mouse from the water and manually place it on the platform. Allow it to sit there for 30 seconds. Record this as a 30 second value in your data
4. After 30 seconds remove mouse from the water maze and return it to the cage. 5. Perform an additional nine runs (steps 2-3) for a total of ten runs 6. Omit step 1 for all subsequent trials (trials 2-10) 7. Make sure you record the data 8. Graph your results (using graph paper). Seconds to find the platform ( y - axis) vs. trial number 1-10 (x - axis) Question: Based on your results is there any indication that the mice learned the location of the platform? Explain.
Experiment 2: EEG In this section you will do an EEG on yourself. See ADI PowerLab instructions
Student Handout
Electroencephalography (EEG)
Page 1 of 7 ©2007 ADInstruments
Introduction In this laboratory, you will explore the electrical activity of the brain. You will record and analyze electroencephalograms (EEGs) from a volunteer; look at interfering signals, and examine the effect on alpha and beta waves by opening and shutting the eyes, auditory and mental cues. Background The cerebral cortex contains huge numbers of neurons. Activity of these neurons is to some extent synchronized in regular firing rhythms ('brain waves'). Electrodes placed in pairs on the scalp can pick up variations in electrical potential that derive from this underlying cortical activity. EEG signals are affected by the state of arousal of the cerebral cortex, and show characteristic changes in different stages of sleep. EEG signals are also affected by stimulation from the external environment, and brainwaves can become entrained to external stimuli. Electroencephalography is used, among other things, in the diagnosis of epilepsies and the diagnosis of brain death. Recording the EEG EEG recording is technically difficult, mainly because of the small size of the voltage signals (typically 50 µV peak-to-peak). The signals are small because the recording electrodes are separated from the brain's surface by the scalp, the skull and a layer of cerebrospinal fluid. A specially designed amplifier, such as the Bio Amplifier built into the PowerLab, is essential. It is also important to use electrodes made of the right material, and to connect them properly. Even with these precautions, recordings may be spoiled by a range of unwanted interfering influences, known as 'artifacts'.
In this laboratory you will record EEG activity with two electrodes: a frontal electrode on the forehead, and an occipital electrode on the scalp at the back of the head (Figure 1). A third (ground or earth) electrode is also attached, to reduce electrical interference. In clinical EEG, it is usual to record many channels of activity from multiple recording electrodes placed in an array over the head.
Student Handout
Electroencephalography (EEG)
Page 2 of 7 ©2007 ADInstruments
Figure 1. Equipment setup (with PowerLab 15T).
Origins of the EEG signals
The EEG results from slow changes in the membrane potentials of cortical neurons, especially the excitatory and inhibitory postsynaptic potentials (EPSPs and IPSPs). Very little contribution normally comes from action potentials propagated along nerve axons. As with the ECG, the EEG reflects the algebraic sum of the electrical potential changes occurring from large populations of cells. Therefore, large amplitude waves require the synchronous activity of a large number of neurons. The rhythmic events that these waves reflect often arise in the thalamus whose activity is in turn affected by a variety of inputs including structures in the brainstem reticular formation.
Components of the EEG waveform
The EEG waveform contains component waves of different frequencies. These can be extracted and provide information about different brain activities. The LabTutor software is set up so that the raw EEG signal is displayed in channel 1. Digital filtering allows this to be analyzed into the component frequencies of interest that are displayed in other channels. Each these waves (or rhythms) provides information about different brain states. These waves are:
Student Handout
Electroencephalography (EEG)
Page 3 of 7 ©2007 ADInstruments
1. Alpha (8 to 13 Hz; average amplitudes 30 to 50 µV)
Alpha rhythm is seen when the eyes are closed and the subject relaxed. It is abolished by eye opening and by mental effort such as doing calculations or concentrating on an idea. It is thus thought to indicate the degree of cortical activation, the greater the activation, the lower the alpha activity. Alpha waves are strongest over the occipital (back of the head) cortex and also over frontal cortex.
2. Beta (13 to 30 Hz; <20 µV)
In awake, alert individuals with their eyes open, the dominant rhythm is beta. It may be absent or reduced in areas of cortical damage and can be accentuated by sedative-hypnotic drugs such as benzodiazepines and barbiturates.
3. Theta (4 and 8 Hz; <30 µV)
Theta rhythm is said not to be seen in awake adults but is perfectly normal in awake children up to adolescence. It is normal during sleep at all ages. (Note however, that some researchers separate this frequency band into two components, low theta (4 - 5.45 Hz) activity that they correlate with decreased arousal and increased drowsiness, and high theta (6 - 7.45 Hz) activity that it is claimed is enhanced during tasks involving working memory.)
4. Delta (between 0.5 and 4 Hz; up to 100 - 200 µV)
Delta rhythm is the dominant rhythm in sleep stages 3 and 4 but is not seen in the conscious adult. It tends to have the highest amplitude of any of the component EEG waves. Note that EEG artifacts caused by movements of jaw and neck muscles can produce waves in the same frequency band.
4. Gamma (between 30 and 50 Hz)
Some people also recognize gamma waves but their existence and importance is more controversial. It may be associated with higher mental activity, including perception and consciousness and it disappears under general anesthesia. One suggestion is that the gamma rhythm reflects the mental activity involved in integrating various aspects of an object (color, shape, movement, etc) to form a coherent picture. Interestingly, recent research has shown that gamma waves are enhanced in Buddhist monks during meditation and are absent in schizophrenics.
Student Handout
Electroencephalography (EEG)
Page 4 of 7 ©2007 ADInstruments
It is not presently possible to relate the EEG waves to specific underlying neuronal activities. In general, the more active the brain the higher the frequency and the lower the amplitude of the EEG. Conversely, the more inactive the brain the lower the frequency and the higher the amplitude of the signal.
The EEG during sleep
It is established that the EEG pattern provides an indicator of the sleep state. Sleep consists of two very different alternating stages, non-REM and REM (rapid eye movements) sleep. Non-REM sleep is often described in four stages that are characterized by a progressive increase in sensory thresholds, an increase in EEG wave amplitude, and a decrease in EEG wave frequency. Stage 1 is marked by drowsiness and drifting in and out of consciousness, This is followed by stages 2 and 3 and then 4. Sleepers then move back through the stages except that rather than stage 1, REM sleep occurs. The whole cycle lasts approximately 90 minutes so that, over the course of an 8 hour 'sleep', the cycle is repeated 4 to 6 times. In the later cycles, the REM component is longer and stages 3 and 4 become shorter.
Figure 2. Sleep cycles.
These stages can be correlated with EEG activity. Stage 1 is associated with decreasing beta activity, alpha activity that becomes less obvious and the emergence of theta activity. Stage 2 has irregular theta activity, short bursts of waves of 12 - 14 Hz called sleep spindles, and sudden increases in wave amplitude (K complexes).
Student Handout
Electroencephalography (EEG)
Page 5 of 7 ©2007 ADInstruments
Figure 3. Sleep spindles.
Stages 1 and 2 are relatively "light" stages of sleep. In stages 3 and 4, delta activity predominates with the distinction between the two being that in Stage 3 sleep there is delta activity for less that 50% of the time. In stages 3 and 4 we are in deep sleep. In REM sleep, which can last from 20 to 60 minutes or more, the EEG is similar to that in Stage 1. REM sleep is the stage most associated with dreaming. Although the EEG shows significant activity during REM sleep, motor activity is inhibited. Levels of brain serotonin and nor-epinephrine alter during these sleep stages. In non-REM sleep stages 1 to 4, serotonin levels are increased whereas during REM sleep, nor-epinephrine, corticosteroids and, in males, testosterone is secreted. Non-REM sleep is characterized by decreases in blood pressure, and heart and respiratory rates. In REM sleep, there is marked variation in heart rate and blood pressure and irregular breathing.
In sleep studies, EOGs and EMGs are often recorded in addition to the EEG. Non-REM sleep is characterized by rolling, uncoordinated and slow eye movements and passively decreased muscle tone, whereas REM sleep has rapid, coordinated eye movements (hence the name) and a little EMG activity reflecting the active inhibition of muscle in this state.
Student Handout
Electroencephalography (EEG)
Page 6 of 7 ©2007 ADInstruments
Figure 4. Sleep stages.
The EEG and changes in intracranial metabolism
Changes in the EEG can be detected in response to changes in the chemical environment of the neurons. One easy way to demonstrate this in a student laboratory is to observe the effects of hyperventilation. Hyperventilation lowers blood PCO2. Since CO2 , being lipid soluble, readily crosses the blood-brain barrier and cell membranes, this in turn results in decreased PCO2 (hypocapnia) in the brain interstitial fluid and within the neurons and glial cells. Thus extracellular and cellular pH is elevated - acute respiratory alkalosis. In addition, blood vessels in the brain constrict with reduction in brain blood flow. The consequences are a change in neuronal activity with slower rhythms and higher amplitudes (increased delta and theta activities) as well as some decrease in alpha activity. There is still debate about whether these EEG changes are a consequence of the metabolic changes or of hemodynamic factors. One possibility is that they arise from depressant effects of the hypocapnia on the brainstem reticular formation and are analogous to the EEG changes seen in the transition from wakefulness to sleep.
The EEG and the functions of the cerebral hemispheres
Efforts have also been made to use EEG recordings to dissect out the contributions of the two hemispheres to brain function. It has been argued that the left hemisphere is the 'logical' half of the brain concerned with reasoning, problem solving and language while the right hemisphere is the more intuitive, creative side concerned with images and spatial processing rather than with language. Careful reading of the literature reveals this to be a major
Student Handout
Electroencephalography (EEG)
Page 7 of 7 ©2007 ADInstruments
oversimplification of cortical organization. In reality, there is little published EEG evidence to lend credence to this hypothesis.
The EEG and personality
Attempts have also been made to relate personality to EEG patterns, perhaps the most famous example being Eysenck's Cortical Arousal Model of Introversion and Extraversion. Eysenck argued that there is some 'optimal' level of electrical activity in the cortex. If we fall below this we tend to be bored and fall asleep; above this we are unable to deal with the activity and feel overwhelmed. In this construct, extraverts need additional mental stimulation (people around them, loud music, etc) to reach this optimal cortical activity whereas introverts avoid such additional stimulation as their cortical activity is already in the optimal region. There has been considerable debate about the extent to which EEG findings support this hypothesis.
Further Reading
• Kraemer et al., Nature, Vol. 434, Page 158 (2005).
What you will do in the laboratory There are five exercises that you will complete during this Lab. 1. EEG artifacts. In this exercise, you will learn to recognize common artifacts
seen while recording an EEG.
2. Alpha & Beta Rhythm. Here you will learn how best to elicit alpha waves in an EEG recording.
3. Effects of mental activity. In this part of the laboratory, you will do some simple arithmetic and observe the effects on the EEG activity.
4. Effects of auditory stimulation. Here you will examine the effects on the EEG of the volume and the type of music.
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Experiment 3: - Do this maze thrice, timing yourself to see if you improve after each trial…
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HOMEWORK:
http://www.zefrank.com/memory/ Play three memory games and report your results in your lab notebook along with the results we obtained in class.
4.
SENSORY PHYSIOLOGY
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4. SENSORY PHYSIOLOGY
Objective: 1. The purpose of this lab is to learn about your OWN senses!
1. Vision Near point Visual acuity Astigmatism Color blindness Peripheral vision/blind spot 2. Olfactory Stimulus intensity Adaptation
Detection, Recognition, and Identification of odors 3. Sound Localization 4. Gustatory
Localization of taste buds 5. Touch Perception
Two point test Sensitivity Neck, forearm, palm, fingertip
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Sensory physiology involves processing information by sensory divisions of the Nervous System. Stimulation (internal or external) acts on receptors, which is converted to an electrical potential. If threshold is reached the signal moves afferently to the CNS where the signal is integrated either consciously, or subconsciously, and then a response moves efferently back to the PNS. Receptors: Chemo-respond to chemical that bind the receptors i.e. oxygen Mechano-respond to mechanical energy i.e. pressure, vibration Thermo-responds to temperature Photo-responds to light Nociceptors-respond to noxious stimuli i.e. tissue damage from pain Somatic Senses: Touch-pressure: found in the superficial layers of the skin (also may be deeper). Some are simple free nerve endings wrapped around hair cells. They are located all over the body, and respond to high frequency vibration, which opens mechanically gated ion channels they rapidly adapt to stimulation. Pain: Are activated by noxious stimulation that has the potential to damage tissue. They produce an adoptive, protective response to environmental stress. Protect the body from tear and ware. The Nociceptive reflex gives protection from potential dangers i.e. winking. Temperature: free nerve endings in the subcutaneous layers of the skin. Cold is sensitive to temps 1 degree below body temp. Warm is stimulated from body temp(37 C) to 65 C; pain is > 65. They are scattered across the body with #cold > #warm. They will adapt (20-40 C).
Proprioreception: mediated by sensory receptors located in the muscles and joints of the body; they make us aware of our body position in space, and the relative location of body parts compared to other parts. Special Senses: Olfaction (Smell): Uses chemoreceptors (thousands) to distinguish between odors. Smell is linked to memories and emotions Gustatory (Taste): closely linked with olfaction, but only has 5 receptors types, which are localized at different positions on the tongue. Bitter – associated with toxic components
Sour – Salty, sweet, umani – are associated with nutrition
Vision: perceives light reflection from the environment, and translates the light into
mental images with the help of the eye’s retina. Photoreceptors – light sensitive Rods – responsible for monochromatic nighttime vision Cones – responsible for light and color activity vision during the day Problems: Myopia – nearsightedness due to elongation of the eyeball (concave); images are brought into focus before the reach the retina Hyperopic – farsightedness due to a shortened eyeball (convex); images are brought into focus behind the retina. Astigmatism – Visual defect created by an unusual curvature of the cornea or lenses
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Hearing: Anatomy: Outer ear serves as a function to collect sound waves and direct them inward. Middle ear is the auditory vesicles with multiplies the vibrations (amplification), and allows for protection (muscles pull bones). Inner ear is composed of the cochlea with many hair cells and fluid, which allows for processing of the fluid waves during vibration. Equilibrium: is the state of balance that is mediated by the semi-circular canals in the inner ear, and through vision. The canals are filled with endolymph, which is set into motion by gravity and acceleration. The hair cells sense the movement and send signals to the brain.
If a Stimulus is Continued Sensory Receptors Adapt & Become Less Sensitive
• If a stimulus is maintained at a constant intensity for a long time the nerve seems to lose interest in it- the nerve has adapted and become less sensitive
• This allows us to tune out background noise, to ignore the touch sensation from our clothing , to lose awareness of the temperature of the room, etc..
• Some nerves, such as those for pressure and touch, are fast-adapting; others, such as those for muscle stretch and some types of pain, are slow-adapting- the sensation lasts a long time
• Example: tenperature receptors o Two types: warm & cold receptors o If one hand is placed in warm water and the other is placed in cold water, the
temperature receptors will adapt and become less sensitive o After adaptation, if both hands are placed in lukewarm water, the hand originally
in warm water will feel cold, and the hand originally in cold water will feel warm •
Skin Sensations are Usually Perceived at the Location of the Receptor
• Somatic (body) senses are perceived to be coming from the location of the sensory receptor
• Sometimes the body is fooled: phantom limb pain- person feels a limb which is no longer present
• Skin sensations are quite complicated: o Merkel cells and Ruffini endings respond to steady pressure o Pacinian corpuscles and Meissner's corpuscles give the sense of vibration o There are separate warm and cold receptors o Receptors associated with skin hairs allow you to feel the displacement of hairs o Several types of pain receptors respond to mechanical trauma or very high or low
temperatures • Uneven distribution of receptors: close together on finger tips & face; far apart on back,
legs, arms, belly
Mechanical Pain Receptors are Naked Nerve Endings
• The impulses perceived as pain are generated by the simplest type of sensory receptor- a naked nerve ending
• Pain receptors are activated by strong stimuli that threaten tissue damage
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• They may be stimulated by chemicals released when tissues are damaged (i.e., histamine)
There are 2 Basic Types of Pain
• There are 2 distinct types of pain, carried by 2 types of nerve fibers. • Slow, unmyelinated C fibers carry pain from deep within the tissues. The pain is felt as a
dull ache which is hard to localize • Fast, myelinated A delta fibers carry sharp, well-localized pain from the surface
http://faculty.washington.edu/chudler/twopt.html
Pre-Lab Questions: From: http://www.queendom.com/tests/quiz/index.htm?idRegTest=917 1. Human’s can’t perceive color: a. Underwater b. In outer space c. In bright moonlight d. when one eye is covered 2. What is Anton’s Syndrome? a. A syndrome characterized by the ability to see shapes clearly but the inability to identify them. b. A syndrome characterized by the ability to see only in black and white. c. A syndrome characterized by a lack of depth perception d. A syndrome characterized by a person’s complete blindness and a vehement conviction that they see. 3. Which of the following creatures cannot move it’s eyes? a. Rabbit b. owl c. chimpanzee d. starling 4. Which animal can see between its open jaws? a. Rabbit b. owl c. chimpanzee d. starling 5. If a 2-person conversation measures 60 decibels and a vacuum cleaner measures 80, what is the decibel level of normal breathing? a. 0 b. 10 c. 25 d. 40 6. What is the decibel level of a jet plane at take-off? a. 90 b. 140. c. 450 d. 1000 7. Of the following, which would be most difficult to vividly conjure up in the imagination (for most, if not all people)? a. Smell of coffee b. color of red c. feel of velvet d. taste of lemon 8. Which taste cannot be detected by the tip of your tonue? a. Bitter b. sour c. salty d. sweet 9. Which of the following body parts is the MOST sensitive to touch? a. Back b. stomach c. lips d. fingertips
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Experiments
Go and try this in the lab before anything:
http://www.bbc.co.uk/science/humanbody/body/interactives/senseschallenge/
1. VISION
Retinoscopy
The eye doctor will often perform this test early in the eye exam in order to obtain an approximation of your prescription from which to start.
In retinoscopy, the room lights will be dimmed and you will be given a large target (usually the big "E" on the chart) to fixate on. As you stare at the "E," the eye doctor will shine a light at your eye and flip lenses in a machine in front of your eyes.
Based on the way the light reflects from your eye, the doctor is able to "ballpark" your prescription — sometimes right on the money! This test is especially useful for children and non-verbal patients who are unable to accurately answer the doctor's questions.
From: http://illinoiseyecenter.com/
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The Ishihara Color Test
Is a test for red-green color deficiencies. It was named after its designer, Dr. Shinobu Ishihara, a professor at the University of Tokyo, who first published his tests in 1917. [1]
The test consists of a number of colored plates containing a circle of dots randomized in color and size. Within the randomized pattern are dots which form a number visible to those with normal color vision and invisible, or difficult to see, for those with a red-green color vision defect. The full test consists of thirty-eight plates, but the existence of a deficiency is usually clear after a few plates. Testing the first 24 plates gives a more accurate diagnosis of the level of severity one's color vision defect may be.
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Experiment:
- Chart the distribution of the Ishihara test based on gender.
Question:
- Do males have the same color sensitivity as females?
What is astigmatism?
From: http://www.psych.ucalgary.ca/PACE/VA-Lab/AVDE-Website/astigmatism.html
The cornea is responsible for about 2/3 of the eye’s refractive power needed to focus on the retina; the lens provides the other 1/3. If the surface of either of these optical components is not smoothly spherical, (i.e., less curved across some orientations than others) some orientations will be better focused than others. This visual defect, normally due to asymmetries in the curvature of the cornea is termed astigmatism. Clinicians distinguish between two general types of astigmatism: with-the-rule and against-the-rule. In with-the-rule astigmatism, the eye has more refractive power along the vertical axis and the patient has difficulty resolving targets with horizontal lines (e.g., letters such as E or F). A patient with against-the-rule astigmatism has the opposite problem; they have difficulty focusing vertically oriented targets.
If you would like to see if you might have astigmatism, look directly at the center of the chart below, using the eye you want to test (close the other eye). Without shifting your gaze, note whether the lines along some orientations look lighter or more blurry than others. If they do, you may have astigmatism and may want to consult your eye-care practitioner (i.e., optometrist or ophthalmologist).
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2. OLFACTORY
In this section you will smell a set of different odors and you will be required to identify them.
3. SOUND (From: http://www.cigna.com/healthinfo/tv8475.html
Tuning fork tests
A tuning fork is a metal, two-pronged device that produces a tone when it vibrates. The health professional strikes the tuning fork to make it vibrate and produce a tone. These tests assess how well sound moves through your ear. Sometimes the tuning fork will be placed on your head or behind your ear. Depending on how you hear the sound, your health professional can tell if there is a problem with the nerves themselves or with sound getting to nerves.
Purpose: a vibrating tuning fork held next to the ear or placed against the skull will stimulate the inner ear to vibrate, and can help determine if there is hearing loss. (http://www.rwjhamilton.org)
Two types of hearing tests with tuning forks are typically conducted. In the Rinne test, the vibrating tuning fork is held against the skull, usually on the bone behind the ear (mastoid process) to cause vibrations through the bones of the skull and inner ear. It is
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also held next to, but not touching, the ear, to cause vibrations in the air next to the ear. The patient is asked to determine which sound is louder, the sound heard through the bone or through the air. A second hearing test using a tuning fork is the Weber test. For this test, the stem or handle of the vibrating tuning fork is placed at various points along the midline of the skull and face. The patient is then asked to identify which ear hears the sound created by the vibrations. Tuning forks of different sizes produce different frequencies of vibrations and can be used to establish the range of hearing for an individual patient.
FIGURE 4. Weber test. Holding a 512-Hz or 1,024- Hz tuning fork on the middle of the patient's forehead, the physician asks, "Where do you hear this loudest--left, right or in the middle?" The sound localizes toward the side with a conductive loss (toward the worse-hearing ear) or away from the side with a sensorineural loss (toward the better-hearing ear). The physician can clarify this test by performing the test on himself or herself, plugging one ear with a finger to simulate a conductive loss. The Weber test is only useful if there is an asymmetric hearing loss. If hearing is symmetric, the patient perceives the sound in the middle of the forehead.
FIGURE 5. Rinne test. Holding a 512-Hz or 1,024-Hz vibrating tuning fork against the mastoid process, the physician asks the patient to indicate when the sound can no longer be heard. At this point, the physician places the tuning fork in front of the auditory meatus to determine whether the sound can be heard again. Normal hearing patients and patients with sensorineural hearing loss hear the sound longer through air than bone. The result is reported as "AC > BC" (air conduction greater than bone conduction). In a conductive hearing loss, bone conduction becomes equal to or greater than air conduction. This result is reported as an "abnormal Rinne" or "reversed Rinne."
From: www.aafp.org/afp/20000501/2749.html
4. GUSTATORY
bitter - Bitter tastes (like the taste of tonic water) are mostly sensed towards the back and rear sides of the tongue. salty and sweet - Salty tastes and sweet tastes (like sugar) are mostly tasted at the tip of the tongue.
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sour - Sour tastes (like lemon juice) are mostly tasted at the sides of the tongue, at the middle and towards the front.
5. TOUCH PERCEPTION
From: http://www.usd.edu/coglab/2point.html
Touch acuity is conventionally measured using the two-point threshold test. The basic question is this: How far apart do two separate points need to be before they are perceived as two points rather than one? In this experiment we will test the sensitivity of five separate areas of the skin: the pad of the middle finger, the dorsal (or backside) of the middle finger, the back of the hand, the forearm, and upper arm. Begin the experiment by forming a 2 person team. Next, decide who will do the testing and who will be the participant. The person chosen to be the experimenter will begin by calibrating the test apparatus (an adjustable 2-point caliper) to a inter-point gap size of 1 mm (using a ruler).
Start with the fingertip and then continue through the five testing areas using a gap size of 1mm. After testing each area record whether the participant perceives one or two points on the skin surface. Once you have tested all five areas at 1mm of separation (and record the responses) proceed to test all five areas in the same sequence at the following increments: 2mm, 3mm, 4mm, 5mm, 10mm, 15mm, 20mm, 25mm, and 30mm. Be sure to record the amount of separation and whether the participant can perceive two separate points. Once the participant has perceived two points on two consecutive trials feel free to skip that testing area, and use the 1st two-point increment as the threshold value. For example, if on the back of the hand the participant feels two points at 10mm and 15mm, use 10mm as the threshold. Proceed through the remaining increments until the participant can feel two separate points on each of the five testing areas.
1mm 2mm 3mm 4mm 5mm 10mm 15mm 20mm 25mm 30mm
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Two-touch point Report
1. What is the independent variable?
2. What is the dependent variable?
3. What was the psychophysical method used in this experiment?
4. Plot your threshold as a function of the tested area.
5. What is the relationship between the two-point threshold and the tested area? Why is this so?
(From http://www.usd.edu/psyc301/2point.htm)
Temperature test:
1) place one hand in warm water (35oC) and the other in cold water (4oC). 2) Leave your hands in the water until you do not feel any more the temperatures of the
water bath. 3) Remove your hands fast and deep them into a room temperature bath (23oC). 4) Record your sensation.
Pad of Middle Finger
Back of Middle Finger
Back of Hand
Forearm
Upper Arm
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PATELLAR REFLEX
A spinal reflex is one in which the decision to react is made at the level of the spinal cord, allowing extremely rapid reaction without awaiting the participation of the brain. Protective reactions and postural adjustments are typical examples of this kind of spinal reflex.
Typically it will involve a sequence of neurons consisting of a sensory neuron, an internuncial or association neuron, and a motor neuron for a bisynaptic reflex arc. Monosynaptic arcs consist of only a sensory and a morot neuron. We will explore the best know of spinal reflexes, a stretch reflex called the patellar reflex (a monosynaptic reflex).
1) Muscle spindles (transducers in quadriceps) are stretched (golgi tendon organs may detect increased tension, usually only when active contraction occurs) 2) sensory impulses are carried on dendrites up along a spinal nerve to the unipolar sensory neuron (ganglion cell) in the dorsal root ganglia. 3) IF BISYNAPTIC: the ganglion cell relays the impulse out along its axon into posterior gray horn of spinal cord, where it synapses with an association or internuncial neuron. 4) The internuncial neuron sends an impulse along its axon to a motor neuron in the anterior gray horn. 5) The motor neuron sends an impulse along its axon out through the ventral root, through the spinal nerve to quadriceps femoris. At the motor endplate, acetylcholine is released, causing
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contraction of the muscle. The leg kicks...
PRODUCING THE PATELLAR REFLEX
1) Construct a data table to record the patellar reflex of the right versus the left leg for you and your bench partner.
2) Have your partner sit on edge of table or with legs crossed so that leg swings freely.
3) Locate the tibial tuberosity and the lower edge of patella.
4) With a percussion hammer, strike with the pointed end in the center of the soft space between these two hard landmarks.
5) Experiment with striking in various locations to see where the most pronounced reaction is elicited. Repeat for the other leg.
6) Describe the reflexive reactions of the R versus the L leg of your benchmates, record in the data table. Compare yours with your benchmates.
Post-Lab Questions
1. In light of your discoveries during class, what do your think is your keenest sense and why? 2. What is your weakest sense and why?
5.
MUSCLE PHYSIOLOGY I
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5. MUSCLE PHYSIOLOGY I
Objective:
1. Learn the molecular aspects of muscle contraction. 2. Learn about muscle fatigue.
I. There are 3 Major Muscle Types A. Smooth Muscle
Non-striated muscle that lines the blood vessels, and organs. Is made up of smooth spindle fibers with only 1 nucleus. Has involuntary contraction, which are slower & prolonged due to no t-tubules.
= better for things like digestion
B. Cardiac Muscle Striated muscle fibers with one central nucleus and a higher number of mitochondria for the large amount of O2 supply required. This muscle is NOT under voluntary control. Cells are joined by tight junctions and separated by thick sarcolemma called inter-collated discs
C. Skeletal muscles Striated muscles have multiple nuclei due to cell fusion during development. Inside each cell cylindrical cells there are large numbers of myofibrils, composed of Sarcomeres units (contractile unit). Inside each sarcomere there are two main type of fibril/proteins/myofilaments:
a. thin filaments: actin b. thick filaments: Myosin
II. Muscle contraction 1. The brain sends an action potential down the axon of a motor neuron. At the nerve
end (synapse) the cell releases the neurotransmitters (acetylcholine) into the neuromuscular junction.
2. ACh binds to the nicotinic receptor on the muscle cell membrane, allowing Ca2+ to enter the cells.
3. The Ca2+ enters the muscle cell activating troponin and tropomysin; causing them to change conformation, and uncovering the A:M binding site;
4. The muscle is depolarized and Sarcoplasmic Reticulum releases more Ca2+ into the muscle.
5. In order to reach relaxation, the Ca2+ has to be removed from the cell. 6. Contractions (sliding of acting over myosin) require energy: from the hydrolysis of
ATP. When quick energy stores are empty, the body uses creatine-phosphate to “steal” Phosphate, add it to ADP and thus make one extra ATP.
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III. Summation The body recruits different muscle fibers to keep the muscle contraction for long periods of time. Summation occurs when more than 1 stimulus is applied @ increasing frequencies. The result is that it increases the strength of the muscle but the fibers don't have time to relax. IV. Tetanus Is the maintenance of sustained muscle contraction. It means that there is contraction without ANY fiber relaxation, it has recruited all fibers and will last for a finite amount of time. See: http://www.unmc.edu/Physiology/Mann/mann14.html And: http://csm.jmu.edu/biology/danie2jc/muscles/muscles.htm Weight lifting: isometric contractions
Cardiac output and blood pressure increase, and arterioles in the exercising muscles undergo vasodilation. However, once the contracting muscles exceed 10-15% of their maximal force, the blood flow to the muscle is greatly reduced because the muscles are physically compressing the blood vessels that run through them; the arteriolar vasodilation is completely overcome by the physical compression of the blood vessels.
Therefore, isometric contractions may be maintained only briefly before fatigue sets in. In addition, because of blood vessels compression, total peripheral resistance may go up considerably, contributing to a large increase in mean arterial blood pressure.
Maximal oxygen consumption (VO2max) After VO2max is reached, work can be sustained only very briefly by anaerobic metabolism in the exercising muscle. Theoretically, VO2max can be limited by:
1. the cardiac output. 2. the respiratory system ability to deliver oxygen to the blood. 3. the exercising muscle ability to use oxygen. 4.
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In normal people, except highly trained athletes, cardiac output is the factor that determines VO2max. With increasing work load, heart rate increases progressively until it reaches a maximum. Stroke volume increases less and tends to level off when 75% of VO2 max has been reached. KEY TERMS anabolic - in reference to muscle, a net increase in muscle protein catabolic - in reference to muscle, a net decrease in muscle protein concentric - shortening of a muscle during contraction eccentric - lengthening of a muscle during contraction hyperplasia - increase in cell number hypertrophy - increase in cell size isometric - no change in muscle length during a contraction mitochondria - is an organelle ("little organ") found within cells and is involved in generating ATP via aerobic processes muscle fiber - also known as a myofiber; is the multinucleated cell of skeletal muscle myoblast - an immature muscle cell containing a single nucleus myogenesis - the development of new muscle tissue, esp. its embryonic development
Pre-lab Questions: 1. What muscle is the only muscle in your body attached at one end? 2. How many muscles does the human body have? 3. How many muscles does the tongue have? 4. What is the strongest muscle in the human body? 5. Over the course of a lifetime, what muscle works the hardest? 6. Discuss fresh muscle compared with preserved muscle and what you think could improve the overall results of this experiment. http://www.brookscole.com/chemistry_d/templates/student_resources/shared_resources/animations/muscles/muscles.html Webpage with excellent info on exercise: http://home.hia.no/~stephens/exphys.htm
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Experiments Do in Class: Investigation: Muscle Contraction
The Muscle Contraction Investigation is scheduled directly after the benchmark lesson on cellular respiration. The purpose of this lab is to: 1) Allow students to see muscle contraction occur in the presence of ATP; and 2) Initiate student exploration into other factors that must be present for contraction. Though not directly part of this project, discussion about the other factors necessary for contraction, like KCl and MgCl2, will serve as a springboard into a more in-depth discussion of muscle contraction.
Learning objectives:
A. Each student will make predictions as to the substances that are necessary for muscle contraction.
B. Each student will test muscle reaction to various substances and observe muscle contraction in the presence of the necessary substances.
C. Each student will determine which substances are necessary for muscle contraction and formulate hypothesis to explain why such substances are necessary.
Materials needed: A. Lab Notebook
B. Vial of solution A - .25% & ATP solution in distilled water
C. Vial of solution B - .25% ATP solution in water + .05 M KCl + .001 M MgCl2 in distilled water
D. Vial of solution C - .05 M KCl + .001 M MgCl2 in distilled water
E. tube of psoas muscle in glycerol
F. microscope slides
* The muscle tissue sample has been tied to a wooden rod, stored in glycerin, and kept in the freezer. The muscle bundle was tied to the wooden rod before being cut from the main muscle in the rabbit to prevent contraction. It is kept in glycerol to prevent freezing of the muscle myofibrils. The low temperature is required to prevent destruction of the
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enzymes present in the tissue sample.
Student Procedures C. In groups of 3, acquire one small 2cm length of psoas muscle.
D. Place the bundle in a small drop of glycerol on a microscope slide.
E. Tease the bundle of muscle fibers into individual muscle fibers.
F. Align 3 individual fibers on each of three different microscope slides and place one fiber on a forth slide.
G. Observe the single fiber under high power under a compound microscope. Draw a diagram of the muscle fiber.
H. Measure the length of each fiber in mm. Record measurements.
I. Add several drops of solution A to each of the three fibers on one of the microscope slides.
J. After 30-45 seconds, measure each of the three fibers. Record your measurements.
K. Was the length of the fiber the only dimension that changed?
L. Observe one of the fibers under a compound microscope and compare with the original relaxed fiber you observed? Record your observations in your notebook.
M. Repeat steps with solution B and then with solution C with new sets of fibers.
Post-Lab Questions 1. Was your original hypothesis correct? Give a reason for why or why not. 2. Based on your data, determine what substances are necessary for muscle contraction. 3. Why are these substances necessary? You may wish to check with different references to help answer this last question.
6.
MUSCLE PHYSIOLOGY II
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6. MUSCLE PHYSIOLOGY II Objective:
1. Learn about summation and tetanus contraction. 2. Learn about muscle strength.
Pre-Lab questions: 1. How many muscles does it take to smile? 2. How many muscles does it take to frown? 3. How many pounds of pressure can your jaw muscles exert when chewing? 4. How much (%) of the average human body is muscle? 5. What is the longest muscle in the body? 6. How many muscles does it take to lift your eyebrows? See: http://csm.jmu.edu/biology/danie2jc/muscles/muscles.htm
Experiment 1:
ADI Muscle contraction Experiments
Experiment 1. Effect of Stimulus Strength: Threshold stimulus, and maximal response (Spatial Summation):
Experiment 2. Effect of Stimulus Frequency (Temporal Summation)
Experiment 2:
Use PowerLab experiment to measure muscle contraction strength.
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Experiment 3: From: http://www.exrx.net/WeightExercises/Biceps/DBCurl.html And: http://exercise.about.com/od/exerciseworkouts/ss/howtosquat.htm Dumbbell Curl Preparation: Position two dumbbells to sides, palms facing in, arms straight. Execution: With elbows to the sides, raise one dumbbell and rotate forearm until forearm is vertical and palm faces shoulder. Lower to original position and repeat with opposite arm. Continue to alternate between sides. Comments: Biceps may be exercised alternating (as described), simultaneous, or in a simultaneous-alternating fashion. When elbow is fully flexed, elbow should only travel forward slightly allowing forearm to be no more than vertical to allow for a relative release of tension in muscles between repetitions. Also see mechanical analysis of arm curl. Dumbbell Single Leg Calf Raise Instructions Preparation Grasp dumbbell in one hand to side. Position toes and balls of feet on calf block with arches and heels extending off. Place hand on support for balance. Lift other leg to rear by bending knee. Execution Raise heels by extending ankles as high as possible. Lower heels by bending ankles until calves are stretched. Repeat. Continue with opposite leg. Comments Keep knees straight throughout exercise or bend knees slightly only during stretch. Quadriceps serve as a Synergists muscle if knees are bent slightly during stretch. Use a lighter load if you need to assist with hands used for support. The Wall Sit The wall sit is a bit different from typical squats since you're holding a static position for a certain period of time, rather than working through an entire range of motion. This is a great exercise you can do anywhere without any equipment to help you build endurance in the lower body. Here's how to do it: 1. Stand in front of a wall (about 2 feet in front of it) and lean against it. 2. Slide down until your knees are at about 90-degree angles and hold, keeping the abs contracted, for 20-60 seconds. 3. Come back to start and repeat, holding the squat at different angles to work the lower body in different ways. 4. To add intensity, hold weights or squeeze a ball between the knees.
Laboratory Handout Electromyography (EMG)
2005 ADInstruments Page 1 of 5
Introduction In this laboratory, you will explore the electrical activity of skeletal muscle by recording an electromyogram (EMG) from a volunteer. You will examine the EMG of both voluntary and evoked muscle action, and use this technique to measure nerve conduction velocity.
Background Skeletal muscles do the majority of the work for locomotion and support of the animal skeleton. Each muscle is made up of individual muscle fibers organized in fascicles (Figure 1).
Figure 1. Skeletal muscle structure. Each individual fiber is innervated by a branch of a motor axon. Under normal circumstances, a neuronal action potential activates all of the muscle fibers innervated by the motor neuron and its axonal branches. The motor neuron, together with all of the individual muscle fibers that it innervates, is termed a motor unit (Figure 2). This activation process involves the initiation of an action potential (either voluntarily, or as a result of electrical stimulation of a peripheral nerve), conduction of the action potential along the nerve fiber, release of neurotransmitter at the neuromuscular junction and depolarization of the muscle membrane with resultant contraction of the muscle fibers.
Laboratory Handout Electromyography (EMG)
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Figure 2. The components of a motor unit. Electromyography is a technique that measures the electrical activity of the muscles and the nerves controlling the muscles. The data recorded is an Electromyogram (also known as an ‘EMG’ or ‘Myogram’). There are two methods of recording: needle electrodes inserted through the skin into the muscle, or electrodes placed on the skin surface. The size and shape of the waveform measured provide information about the ability of the muscle to respond when the nerves are stimulated. In the clinical setting, EMG is most often used when people have symptoms of weakness, and examination shows impaired muscle strength. It can help to differentiate muscle weakness caused by neurological disorders from other conditions. The EMG provides a depiction of the timing and pattern of muscle activity during complex movements. The raw surface EMG signal reflects the electrical activity of the muscle fibers active at that time. Motor units fire asynchronously and it is sometimes possible, with exceedingly weak contractions, to detect the contributions of individual motor units to the EMG signal. As the strength of the muscular contraction increases, however, the density of action potentials
Laboratory Handout Electromyography (EMG)
Page 3 of 5
increases and the raw signal at any time may represent the electrical activity of perhaps thousands of individual fibers. In the first exercise, you will record EMG activity during voluntary contractions of the biceps and triceps muscles of the arm (Figure 3).
Figure 3. Skeletal muscle structure. The raw EMG signal during voluntary contractions may be processed in various ways to indicate the intensity of EMG activity. In the method used here, the negative-going portions of the EMG are inverted, and then the whole signal is integrated in such a way as to smooth out individual spikes, and make the time course of changing activity much clearer. In this part of the exercise you will examine coactivation: a phenomenon in which contraction of a muscle leads to more minor activity in the antagonist muscle. The physiological significance of this is not entirely clear, but it has been suggested that it helps to stabilize the joint. You will also record evoked EMG signals produced by electrical stimulation of a motor nerve supplying a muscle. The abductor pollicis brevis muscle is a member of the thenar muscle group on the palmar surface of the hand (Figure 4).
Laboratory Handout Electromyography (EMG)
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Figure 4. Some muscles of the forearm and hand. The motor nerve to the abductor pollicis brevis muscle (the median nerve) is easy to stimulate at the wrist and elbow. In this exercise, flat metal disc electrodes are attached to your skin. Brief electrical pulses are administered through the skin to the nerve, and the time it takes for the muscle to contract in response to the electrical pulse is recorded. The speed of the response is dependent on the conduction velocity. In general, the range of normal conduction velocities will be approximately 50 to 60 meters per second. However, the normal conduction velocity may vary from one individual to another and from one nerve to another. Nerve and muscle disorders cause the muscles to react in abnormal ways. Measuring the electrical activity in muscles and nerves can help detect the presence, location and extent of diseases that damage muscle tissue (such as muscular dystrophy) or nerves (such as amyotrophic lateral sclerosis: Lou Gehrig's disease). In the case of nerve injury, the actual site of nerve damage can often be located. In a clinical setting, EMG and nerve conduction studies are usually done together. When external nerve stimulation is applied, the volunteer will feel a brief 'pinch', a tingling sensation and a twitching of the muscle. It may feel similar to the static discharge felt when rubbing one's feet on the carpet and then touching a metal object. In our exercises, each electrical pulse is very brief (less than a millisecond). The energy of electrical pulses is not high enough to cause an injury or damage. There are no risks associated with these small currents. Nothing is inserted into the skin, so there is no risk of infection.
Laboratory Handout Electromyography (EMG)
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What you will do in the Laboratory You will perform four exercises: 1. Voluntary change in contractile force. You will record EMG during voluntary
muscle contractions, and investigate how contractile force changes with increasing demand.
2. Alternating activity and coactivation. Here you will examine the activity of antagonist muscles and the phenomenon of coactivation.
3. Evoked EMG. In this exercise, you will record EMG responses evoked by stimulating the median nerve at the wrist.
4. Nerve conduction velocity. In this exercise, you will measure nerve conduction velocity from the difference in latencies between responses evoked by nerve stimulation at the wrist and the elbow.
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Post-Lab questions:
Study the graphs representing, twitch, wave summation, Incomplete tetanus, & complete tetanus
7.
BLOOD
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7. BLOOD
Objective: 1. The purpose of this lab is to learn about blood clotting and about different
blood types. I. Functions of Blood
Blood functions as a transporter. It brings nutrients and oxygen to the cell and removes waste/CO2 from interstitial fluid around the cell.
II. Blood Composition A. Plasma: Organic Molecules i.e.Plasma Proteins (Albumin, Globulin, Fibrinogen), 7% Water-92%, Ions, Vitamins, Gases. B. Cellular Materials: Red Blood Cells (RBC), White Blood Cells and Platelets. II. Cell Types A. Erythrocytes (RBC’s) – transport O2 and CO2 with lungs and tissues; do not have a nucleus or membrane bound organelles, are shaped as a biconcave disc, are filled with enzymes and hemoglobin and live approximately 120 days. B. Leukocytes (WBC’s) are grouped based on function:
1. Immunocytes are responsible for immune responses directed against invaders Lymphocytes (produce antibodies)- 25%
2. Phagocytes engulf and ingest foreign particles Monocytes (become macrophages)- 2 to 4%
Neutrophils- 65% 3. Granulocytes contain cytoplasmic inclusions Basophils- less than 1%
Eosionophils- 4 to 5 % (to some extent Neutrophils) C. Thrombocytes (Platelets)
Have a 10 day life span. They are present always in the blood, and upon activation (damage to the circulatory walls), they are responsible for the clotting of blood.
Hemoglobin is an oxygen carrying pigment of RBC’s; It is a large complex molecule that can be oxygenated or deoxygenated; It is composed of 4 globin protein chains, and has an iron core. The molecule can hold 4-O2 molecules, attachment of the last 3 facilitated by the attachment of the first. III. Diseases Associated with Red Blood Cells
A. Anemia is caused when either the blood hemoglobin content is low, and not enough O2 gets transported, or there is a low RBC count, or there is abnormal shapes and structures of the two.
B. Iron deficient anemia: Hemoglobin is not made properly due to low iron C. Sickle Cell Anemia: abnormal Hgb disrupts the shape of the RBC, causing a clogging of
the arteries during blood flow D. Hematopoiesis Erythroblastosis fetalis
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Hematocrit is the percent of the total blood volume that is occupied by RBC, and is used in disease diagnosis. Normal is 42% RBC, with 58% platelets. IV. Blood Typing
1. Blood can be used as an identifier in paternity, and as a sign for a threatening disease (heart attack).
2. The antigens (proteins on the outside of the cell) present are genetically determined; they are responsible for triggering immune responses by reacting with antibodies. RBC antigens: A, B, and O (none) Blood Type A has the A antigen and is tested for using anti-B antibodies B B anti-A AB A & B anti-A or anti-B O does not have an antigen both A & B antibodies
V. Genetics
A. Our chromosomes carry our DNA as genes that have been expressed; the gene carries the info needed to produce the required protein. B. We get a pair of genes (alleles) for blood type, allowing for many possible combinations:
1. Homozygous is when both chromosomes have the same allele 2. Heterozygous is when you get two different alleles, and if both alleles are equally
expressed, there is co-dominance, and you have an AB blood type.
C. Your genotype is the genetic composition D Your phenotype is the outward appearance PHENOTYPE GENOTYPE/Ag Ab DONATE RECEIVE A AA, AO A A, AB A, O B BB, BO B B, AB B, O AB AB AB AB AB, A, BO O OO - any/universal O AB is the universal recipient, and O is the universal donor VI. Rh factor
A. Presence of Rh makes you Rh+, and the absence makes you Rh- B. It is a dominant trait, so if homo recessive you will not have the antigen on
your RBC. C. It is a problem in pregnancy with a – mom and a + dad, because you may
have a + baby; during the second pregnancy the mom’s body will have created antibodies against the antigen from the first baby, and it will destroy the fetus.
Pre-lab questions: 1. What is in a speck of blood? 2. Why are red blood cells shaped like breath-mint discs with a dent in the middle? Why not spheres? Or cubes? 3. What is the study of blood called?
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4. Is blood thicker than water? 5. What happens when blood does not flow well? 6. How do we know that blood moves? 7. How much blood is in your body right now? 8. What body parts make blood? 9. What causes a bruise? 10. Who can donate blood? 11. What is hemophillia? 12. Why do vampire bats feed at night? 13. What is a blood sausage?
Experiment 1: Paternity Test.
Experiment 2: Interactive game: http://nobelprize.org/educational_games/medicine/landsteiner/
8.
ELECTROCARDIOGRAM
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8. ELECTROCARDIOGRAM
Objective: 1. The purpose of this lab is to learn about your heart cycle. 2. Learn about your cardiac capacity and changes during physical activity.
The electrocardiogram is a measure of the electrical pattern of impulses produced in the heart resulting in a rhythmic pattern of contraction of the heart known as the cardiac cycle. Can be used clinically as a diagnostic tool to help reveal heart abnormalities. 1. Cardiac Muscle (Myocardium) The heart is a muscular pump that propels blood through the pulmonary and systemic circulations. The cardiac muscle or myocardium is composed of striated uninucleate or binucleate fibers. Myocardial fibers are electrically connected to one another via specialized gap junctions known as intercalated disks. These connections allow electrical stimuli produced in one region of the heart to spread throughout the tissue. Myogenicity – Term describing the fact that the heart can beat on its own without innervation from the CNS. The electrochemical events that cause the myocardial fibers to contract arise within the heart itself. Atria and Ventricles – The heart is a four-chambered organ comprised of a right and left atria and a right and left ventricle. The atria function in receiving blood from the pulmonary and systemic circulation while the ventricles are thick walled (muscular) chambers that function in pumping the blood out of the heart. Septum – Connective tissue found between the atria and ventricles. Divides the heart into four chambers and provides electrical insulation. 2. Control of Cardiac Cycle The cardiac cycle is composed of a contraction period known as systole and a relaxation period known as diastole. During the cycle, blood received in the atria is pushed into the ventricles due to the downward contraction of the myocardial fibers of the atria. Blood within the ventricles is pumped out of the heart due to the upward contraction of the ventricular walls. This arrangement results in a directionality of contraction whereby both atria contract prior to ventricular contraction. Therefor blood entering the atria is pumped into the ventricles then pumped out of the heart. Sinoatrial node (SA) – Group of cells located in the upper right atria, regulate cardiac cycle by initiating depolarization waves at a rate of 100/min. The SAN is also referred to as the pacemaker or pattern generator because it controls the waves generated that eventually spread though out the myocardium resulting in contraction. Atrioventricular node (AV) – Group of specialized cells located at the base of the intra-atrial septum. Help delay the signal to ensure atria contract prior to ventricles.
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Bundle of His – Fibers that carry the depolarizing signal from the AVN through the inter-ventricular septum towards the apex (base) of the heart. Purkinje Fibers – Specialized fibers that stem from the apex and branch upward along the ventricular wall. Function in carrying the depolarizing signal upward resulting in an upward contraction of the ventricles which pushes the blood out into the systemic and pulmonary circulation.
3. Electrocardiogram (From: http://anatimation.com/cardiac-cycle/cardiac-cycle-events-of-the-cardiac-cycle.html) The electrocardiogram (ECG) is an indirect measure of the electrical activity of the heart. The activity can be measured by placing leads on the surface of the skin. The ECG is made up of five points P, Q, R, S and T. The points are grouped together to represent important electrical events in the heart. A normal healthy hearts ecg is represented by 3 distinct waves:
• The P wave, • The QRS complex and • The T wave. •
The P wave represents atrial depolarization followed by atrial contraction. The QRS complex represents ventricular depolarization followed by ventricular ejection. The T wave represents ventricular repolarization. Other than the three mentioned above there are other significant pieces to the ecg: The PR segment is the AV nodal delay. The ST segment is the time it takes for the ventricles to contract and empty. The TP interval is the time during which the ventricles are relaxing and filling. P-wave: atria depolarization QRS complex: depolarization and contraction of ventricles Q-wave R-wave S-wave T-wave: repolarization of the ventricles 4. Neuronal and Endocrine Control of the Cardiac Cycle Both the CIC and CAC (see below) are located within the medulla of the brain stem. These two centers help regulate heart rate, resulting in a normal heart rate of 70-75 beats/min. Specialized chemorecptors that detect [CO2] in the blood help activate these centers.
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Cardioinhibitory Center (CIC) - Parasympathetic division (neurotransmitter: Acetylcholine). Via the vagus nerve the CIC slows the SAN to approx. 70-75 depolarizations/min. (As opposed to the SAN’s own rate of 100 depolarizations/min.) Cardioaccelerator Center (CAC) – Sympathetic division (neurotransmitter: Norepinephrine). Release of norepinephrine increases heart rate during periods of strenuous activity. Epinephrine – Hormone also known as adrenaline. Produced and released into the blood from the adrenal medulla during the “fight or flight” response. Binds to adrenergic receptors with an effect similar to norepinephrine in that it stimulates the SAN and increases heart rate. Additionally since it is released into the circulatory system it has a longer lasting effect.
The major factors limiting the rise in stroke volume: 1. the very rapid heart rate, which decreases diastolic filling time. 2. inability of peripheral factors favoring venous return (respiratory pump, skeletal muscle
pump, venous vasoconstriction, arteriolar vasodilatation) to increase ventricular filling further during the very short time available.
At rest, a trained individual has an increased stroke volume and decreased heart rate with no change in cardiac output. At VO2max, cardiac output increases mostly due to increase in stroke volume; maximal heart rate is not altered by exercise. Increase in stroke volume is due to:
1. effects of training on the heart: possibly greater ventricular contractility and thicker myocardium.
2. peripheral effects: increased blood volume, increased number of blood vessels in skeletal muscles. Training also increases the concentrations of oxidative enzymes and mitochondria in the exercised muscle. These changes increase the speed and efficiency of metabolic reactions in the muscles and permit larger increases-200 to 300%- in exercise endurance, but they do not increase VO2max because they were not limiting it in the untrained individual.
Note
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A sudden and exhausting exercise can sometimes trigger heart attack. In individuals who perform regular physical activity the risk is significantly reduced. In general, the more a person exercises; the better is the protective effect. The protective effect of exercise against heart attacks operates via a number of mechanisms:
1. Decreases heart rate and blood pressure, two major determinants of myocardial oxygen demand.
2. Increases diameter of coronary arteries. 3. Decreases hypertension and diabetes; two major risk factors for atherosclerosis. 4. Decreases total plasma cholesterol concentration with simultaneous increase in the
plasma concentration of cholesterol-carrying lipoprotein (HDL-“good” cholesterol). 5. Decreases tendency of blood to clot and improves the ability of the body to dissolve
blood clots.
Disorders 1. Myocardial ischemia 2. Hypertrophy 3. Bundle-branch block 4. V-fib 5. ventricular contractions 6. Superventricular tachycardia 7. Premature ventricular contractions For better understanding go to: http://www.hhmi.org/biointeractive/ecg/ecg.html And: http://pennhealth.com/health_info/animationplayer/ecg_tool.html
Pre-Lab Questions 1. Name five places that you can feel your pulse. 2. What is a good score for blood pressure? 3. What is the first Korotkoff sound to be heard? 4. What is the second Korotkoff sound to be heard? 5. Which animal would have a lower blood pressure; those that live in water or those that live on land? Why? 6. What is the term for the highest pressure in the circulatory system that reflects the pressures created by contraction of the ventricles? 7. The lowest pressure in the circulatory system, associated with relaxation of the ventricles is called? 8. Define pulse. 9. How much faster does the pulse travel than the blood itself? 10. What do you think is the appropriate blood pressure at birth, toddler-age and a teen? 11. If you have hypertension, what are four things you could do to help?
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Experiments In this lab you will test how exercise affects heart rate.
1. Take ECG of labmate BEFORE exercising. 2. Then, this student should go UP-AND_DOWN the stairwell THREE TIMES. 3. Return for another ECG. 4. Determine how much heart rate changed after exercising.
ECG Before exercise After exercise After 3 minutes
Trained student
Poorly trained student
HOMEWORK: http://home.hia.no/~stephens/hrchngs.htm http://home.hia.no/~stephens/exphys.htm
Laboratory Handout ECG and Heart Sounds
2005 ADInstruments Page 1 of 7
Introduction The beating of the heart is associated with both electrical activity and sound. The pattern of electrical activity recorded at the body surface is called the electrocardiogram or ECG. The aim of this laboratory is for you to record and analyze an ECG from a volunteer, and to examine the relationship between the ECG and the characteristic sounds of the heart.
Background The heart is a dual pump that circulates blood around the body and through the lungs. Blood enters the atrial chambers of the heart at a low pressure and leaves the ventricles at a higher pressure. The high arterial pressure provides the energy to force blood through the circulatory system. Figure 1 shows a schematic of the organization of the human heart and the circulatory system.
Figure 1. A schematic diagram of the human heart and circulatory system.
Blood returning from the body arrives at the right side of the heart and is pumped through the lungs. Oxygen is picked up and carbon dioxide is released. This oxygenated blood then arrives at the left side of the heart, from where it is pumped back to the body.
Laboratory Handout ECG and Heart Sounds
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The electrical activity of the heart Cardiac contractions are not dependent upon a nerve supply. However, innervation by the parasympathetic (vagus) and sympathetic nerves does modify the basic cardiac rhythm. Thus the central nervous system can affect this rhythm. The best known example of this is so-called sinus arrhythmia where respiratory activity affects the heart rate. A group of specialized muscle cells, the sinoatrial, or sinuatrial (SA) node acts as the pacemaker for the heart (Figure 2). These cells rhythmically produce action potentials that spread through the muscle fibers of the atria. The resulting contraction pushes blood into the ventricles. The only electrical connection between the atria and the ventricles is via the atrioventricular (AV) node. The action potential spreads slowly through the AV node, thus allowing atrial contraction to contribute to ventricular filling, and then rapidly through the AV bundle and Purkinje fibers to excite both ventricles.
Figure 2. Components of the human heart involved in conduction.
The cardiac cycle involves a sequential contraction of the atria and the ventricles. The combined electrical activity of the different myocardial cells produces electrical currents that spread through the body fluids. These currents are large enough to be detected by recording electrodes placed on the skin (Figure 3).
Laboratory Handout ECG and Heart Sounds
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Figure 3. Standard method for connecting the electrodes to a volunteer.
The regular pattern of peaks during one cardiac cycle is shown in Figure 4.
Figure 4. One cardiac cycle showing the P wave, QRS complex and T wave.
The action potentials recorded from atrial and ventricular fibers are different from those recorded from nerves and skeletal muscle. The cardiac action potential is composed of three phases: a rapid depolarization, a plateau depolarization (which is very obvious in ventricular fibers) and a repolarization back to resting membrane potential (Figure 5).
Laboratory Handout ECG and Heart Sounds
Page 4 of 7
Figure 5. A typical ventricular muscle action potential.
The components of the ECG can be correlated with the electrical activity of the atrial and ventricular muscle:
• The P-wave is produced by atrial depolarization. • The QRS complex is produced by ventricular depolarization; atrial
repolarization also occurs during this time, but its contribution is insignificant.
• The T-wave is produced by ventricular repolarization.
Heart valves and heart sounds Each side of the heart is provided with two valves, which convert the rhythmic contractions into a unidirectional pumping. The valves close automatically whenever there is a pressure difference across the valve that would cause backflow of blood. Closure gives rise to audible vibrations (heart sounds). Atrioventricular (AV) valves between the atrium and ventricle on each side of the heart prevent backflow from ventricle to atrium. Semilunar valves are located between the ventricle and the artery on each side of the heart, and prevent backflow of blood from the aorta and pulmonary artery into the respective ventricle.
The closure of these valves is responsible for the characteristic sound produced by the heart, usually referred to as a ‘lub-dup’ sound. The lower-pitched ‘lub’ sound occurs during the early phase of ventricular contraction. This is produced by closing of the atrioventricular (mitral and tricuspid) valves. These valves prevent blood from flowing back into the atria. When the ventricles relax, the blood pressure drops below that in the artery, and the semilunar valves (aortic and pulmonary) close, producing the higher-pitched ‘dup’ sound. Malfunctions of these valves often produce an audible murmur, which can be detected with a stethoscope.
Laboratory Handout ECG and Heart Sounds
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The cardiac cycle
The sequence of events in the heart during one cardiac cycle is summarized in Figure 6. During ventricular diastole blood is returning to the heart. Deoxygenated blood from the periphery enters the right atrium and flows into the right ventricle through its open AV valve. Oxygenated blood from the lungs enters the left atrium and flows into the left ventricle through its open AV valve. Filling of the ventricles is completed when the atria contract (atrial systole). In the resting state, atrial systole accounts for some 20% of atrial filling. Atrial contraction is followed by contraction of the ventricles (ventricular systole). Initially, as the ventricles begin to contract the pressure in them rises and exceeds that in the atria. This closes the AV valves. But, until the pressure in the left ventricle exceeds that in the aorta (and in the right ventricle exceeds that in the pulmonary artery), the volume of the ventricles can not change. This is the so-called isovolumic phase of ventricular contraction. Finally, when the pressure in the left ventricle exceeds that in the aorta (and the pressure in the right ventricle exceeds that in the pulmonary artery), the aortic and pulmonary valves open and blood is ejected into the aorta and pulmonary arteries. As the ventricular muscle relaxes, pressures in the ventricles fall below those in the aorta and pulmonary artery, and the aortic and pulmonary valves close. Ventricular pressure continues to fall and once it has fallen below that in the atria, the AV valves open and ventricular filling begins again.
Figure 6. The cardiac cycle.
Laboratory Handout ECG and Heart Sounds
Page 6 of 7
Changes in a variety of parameters during one cardiac cycle are susefully summarized in a figure introduced by Wiggers. A modified form of this is shown in Figure 7. The importance of this representation is that it allows you to see the temporal relationships between the different parameters.
Figure 7. A Wiggers' diagram.
Laboratory Handout ECG and Heart Sounds
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What you will do in the laboratory 1. ECG in a resting volunteer. You will record the ECG, analyze the signal and
observe the effects of slight movement on the signal.
2. ECG recorded from several other volunteers. You will identify and discuss similarities and differences in the ECGs of the different participants.
3. ECG and heart sounds. You will use a stethoscope to listen to the heart and an event marker to determine the relationship between what you are hearing and the ECG being recorded at the same time.
4. ECG and phonocardiography. You will also record the heart sounds (phonocardiogram) together with the ECG.
9.
BLOOD PRESSURE
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9. BLOOD PRESSURE
Objective: 1. The purpose of this lab is to learn about your blood pressure. 2. Learn about blood pressure changes due to physical activity. .
I. Cardiovascular System A. Function of the heart B. Direction of blood flow C. Function of the arteries D. Direction of flow in the arteries E. Function of the circulatory system
1. Delivers nutrients 2. Removes metabolic wastes 3. Gas exchange 4. Maintenance of homeostatic temperature
F. Heart sounds 1. Lub: Ventricle contractions cause the atrioventricals to close 2. Dub: blood from aorta and pulmonary arteries causes the semilunar valves
to close G. Stroke Volume H. Cardiac output: the amount of blood pumped by the heart per minute I. Systemic circulation J. Pulmonary circulation
II. Blood Pressure
A. Systolic Pressure: results from mechanical contraction; when the first sounds are heard B. Diastolic Pressure: relaxation of the ventricles; when the sounds disappear C. Peripheral resistance: the resistence to flow in the small vessels
BP is raised with constriction, and lowered with dilation D. Blood velocity E. Vasodilation F. Vasoconstriction
III. Regulation
A. Medulla Oblongata B. Baroreceptors in vessels respond to pressure, and stretch
Blood pressure is the pressure exerted by the blood on the walls of blood vessel. This pressure will change if there is a change in blood volume, the cardiac output changes, resistance in the arteries, distribution of blood within the cardiovascular system changes, a change in posture and regulation by the sympathetic and parasympathetic changes blood pressure. The ways that each of these factors effect blood pressure are:
1. A change in blood volume- 2. A change in Cardiac output- 3. Change in Resistance-
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4. Distribution of the blood changes- 5. Posture changes- 6. Regulation by the sympathetic and parasympathetic system-
You will be able to measure blood pressure by using a medical instrument called a sphygmomanometer, which is attached to a stethoscope. With this machine you will be able to determine what the systolic (when the vessels are contracted) over diastolic (when the vessels are relaxed) is. The way that this instrument works is the cuff wraps around the right arm and is inflated in till the pressure exerted is more then the systolic pressure in the artery. This results in the blood circulation through that artery to be cut off. As the cuff is deflated the pressure exerted on the arm will lower in till it equals the systolic pressure of the artery. At this time blood flow will begin through the vessel, this is when you will hear the first Korotkoff sound. You will hear these sounds in till the cuff deflates to a pressure that is equal to the diastolic pressure in the artery. The pressure that you hear the first sound at is the systolic pressure and the pressure that you hear the last sound at is your diastolic. For better understanding go to: http://132.241.10.14/bp/bp.swf Purpose: The purpose of this experiment was to study the blood pressure of various people at different body positions.
Pre-Lab Questions 1. Name five places that you can feel your pulse. 2. What is a good score for blood pressure? 3. What is the first Korotkoff sound to be heard? 4. What is the second Korotkoff sound to be heard? 5. Which animal would have a lower blood pressure; those that live in water or those that live on land? Why? 6. What is the term for the highest pressure in the circulatory system that reflects the pressures created by contraction of the ventricles? 7. The lowest pressure in the circulatory system, associated with relaxation of the ventricles is called? 8. Define pulse. 9. How much faster does the pulse travel than the blood itself? 10. What do you think is the appropriate blood pressure at birth, toddler-age and a teen? 11. If you have hypertension, what are four things you could do to help?
Experiment Methods:
1. Obtain a sphygmomanometer 2. Have the patient sit down 3. Wrap the cuff around the right arm 4. Pump the cuff with air in till the pressure squeezes the arm enough to overpower the systolic
pressure in the arteries. Don’t pump the pressure past 140.
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5. Allow the cuff to deflate over a period of time, this will cause the pressure exerted on the arm to drop.
6. As the pressure drops listen for the Korotkoff sounds using a stethoscope. The first sound you hear is the systolic sound and the second sound heard is the diastolic sound.
7. Record where you heard the first Korotkoff sound and the last Korotkoff sound. 8. Repeat this process 3-7 while the patient is reclining, immediately after standing, and after
standing three minutes.
Laboratory Handout Blood Pressure
Page 1 of 3
Introduction In this laboratory, you will become familiar with auscultation (listening to the sounds of the body) and the measurement of blood pressure. The exercises involve measuring your blood pressures using a stethoscope, blood pressure cuff and sphygmomanometer. You will also assess changes in peripheral circulation and the effects of cuff location.
Background The pressure in the arteries varies during the cardiac cycle. The ventricles contract to push blood into the arterial system and then relax to fill with blood before pumping once more. This intermittent ejection of blood into the arteries is balanced by a constant loss of blood from the arterial system through the capillaries. When the heart pushes blood into the arteries there is a sudden increase in pressure, which slowly declines until the heart contracts again. Blood pressure is at its highest immediately after the ventricle contracts (systolic pressure) and at its lowest immediately prior to the pumping of blood into the arteries (diastolic pressure). Systolic and diastolic pressures can be measured by inserting a small catheter into an artery and attaching the catheter to a pressure gauge. Such a direct measurement may be accurate, but is invasive and often inconvenient and impractical. This was, in essence, the method by which blood pressure was first measured by the Rev. Stephen Hales in 1714 on a horse (Figure 1). Simpler estimates of blood pressure can be made with acceptable accuracy using noninvasive, indirect methods. Traditionally, systemic arterial blood pressure is estimated using a stethoscope and a blood pressure cuff connected to a mercury column or other sphygmomanometer (Figure 2). The cuff is placed on the upper arm and inflated to stop arterial blood flow to the arm from the brachial artery; the high pressure in the cuff causes the artery to collapse. The pressure in the cuff is then released slowly. When the systolic pressure in the artery exceeds the cuff pressure, blood slowly flows to the arm through the partially collapsed artery. Because the flow is through a partially occluded vessel, the flow instead of being laminar is turbulent. And therefore this flow can be heard through the stethoscope. These sharp, tapping sounds are called Kortokoff sounds. When Kortokoff sounds are first heard, the cuff pressure approximates systolic pressure. As cuff pressure is reduced further, the sounds heard through the stethoscope increase in intensity and then suddenly become muffled. The cuff pressure at the point of sound muffling approximates diastolic blood pressure.
Laboratory Handout Blood Pressure
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Figure 1. The first direct measurement of arterial blood pressure. Eventually, as the cuff pressure is reduced even more, the sounds disappear completely, and normal flow through the artery is re-established. Since the disappearance of sound is easier to detect than muffling, and since the two occur within a few millimeters of mercury pressure, the disappearance of sound is commonly used to determine diastolic pressure. Note that, in some normal healthy people, the sound can still be heard at pressures appreciably below the true diastolic pressure. In these people, it is not possible to define their diastolic pressure accurately. An alternative method makes use of a simple finger pulse transducer connected to the computer. The cuff is inflated to a pressure that obliterates the finger pulse. As the cuff pressure is released, the finger pulse returns and the pressure at which it reappears is a measure of the arterial systolic pressure.
Laboratory Handout Blood Pressure
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The effects of position on the measured arterial blood pressure It is conventional to reference all arterial blood pressure measurements to the position of the heart. One of the things that will be explored in this laboratory is the effect that position has on the magnitude of the pressure. At this stage, can you think of any factors that would change the pressure if the measurements were performed at levels different from the heart?
Figure 2. Indirect measurement of arterial blood pressure
What you will do in the laboratory During today’s class period you will complete four exercises: 1. Measurement of blood pressure by auscultation. You will learn how to measure the blood pressure using a sphygmomanometer cuff and a stethoscope, and appreciate the range of pressure that can be seen in normal people. 2. Measurement of blood pressure with a microphone. In this part of the laboratory, you will record cuff pressure and the Korotkoff sounds. 3. Measurement of systolic pressure from the finger pulse. Here, you will see if you can use pulse measurement to replace the stethoscope. 4. Measurement of systolic pressure in the forearm. Here you will examine the effects of arm position on the systolic pressure determined from finger pulse recordings.
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NAME:_________________
LAB REPORT Maria Smith
Sitting Reclining Immediately standing after reclining
After standing three minutes
Blood pressure (systolic/ diastolic)
Pulse (beats per minute)
Susie Cute Sitting Reclining Immediately standing
after reclining After standing three minutes
Blood pressure (systolic/ diastolic)
Pulse (beats per minute)
Jane Doe Sitting Reclining Immediately standing
after reclining After standing three minutes
Blood pressure (systolic/ diastolic)
Pulse (beats per minute)
Miss America Sitting Reclining Immediately standing
after reclining After standing three minutes
Blood pressure (systolic/ diastolic)
Pulse (beats per minute)
Before Immediately After one minute After 3 minutes
Trained student Poorly trained student
After smoking/coffee 2 min after 3 min after 4 min after Blood pressure Pulse
10.
RESPIRATION
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10. RESPIRATION PHYSIOLOGY
Objective:
1. The purpose of this lab is to learn about your respiratory capacities.
From: http://www.medicine.mcgill.ca/physio/vlab/resp
Lung volumes and capacities are anatomic measurements that vary with age, weight, height and sex of an individual. When affected by disease or trauma, the lung volumes and capacities are altered to a certain degree, depending upon the severity of the disorder. Pulmonary tests can show the effects of disease on function, but they cannot be used to give a diagnosis. However these tests do give valuable quantitative data, allowing the progress of a disease to be followed, or the response to a treatment examined.
This exercise demonstrates techniques for the measurement and evaluation of:
A. Vital capacity of the lung and its subdivisions B. Dynamic lung function tests
Lung volumes that depend upon the rate at which air flows out of the lungs are termed dynamic lung volumes. There are various dynamic tests; in this lab we will perform the Forced Vital Capacity test, and the Maximum Voluntary Ventilation test. The Forced Vital Capacity
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(FVC) is the volume of gas that can be exhaled as forcefully and rapidly as possible after a maximal inspiration. Normally FVC = VC, however in certain pulmonary diseases (characterized by increased airway resistance), FVC is reduced.
From the FVC test, we can also determine the Forced Expiratory Volume in 1 sec (FEV1), which is the maximum volume of air that can be exhaled in a 1 sec time period. Normally the percentage of the FVC that can be exhaled during 1 sec is around 80% (i.e. FEV1/FVC=80%). Maximum Voluntary Ventilation (MVV) is the largest volume of air that can be breathed in and out of the lungs in 1 minute. It will be reduced in pulmonary diseases due to increases in airway resistance or changes in compliance.
From: http://www.medicine.mcgill.ca
About Pulmonary Function Tests From: http://www.nationalasthma.org.au/html/management/spiro_guide/sp_gd003.asp
Spirometry provides an objective assessment of airflow obstruction and is important in staging asthma severity. It should be done on initial diagnosis of asthma, after treatment is started and symptoms have stabilized, and every 1 to 2 years afterward. Spirometry is used to measure the rate of airflow during maximal expiratory effort after maximal inhalation. It can be useful in differentiating between obstructive and restrictive lung disorders. In asthma (an obstructive lung disorder) the forced expiratory volume in 1 second (FEV1) is usually decreased, the forced vital capacity (FVC) is usually normal and the ratio FEV1/FVC is decreased. In restrictive disorders the FEV1 and FVC are both decreased, leaving a normal FEV1/FVC.
Spirometry measurements are usually done before and after administration of a beta2 agonist. Reversibility with the use of a bronchodilator is defined as an increase in FEV1 of 12% or 200 ml. Patients with severe asthma may need a short course of oral steroid therapy before they demonstrate reversibility. Common Terms in Spirometry Below is an example of a volume-time curve. It shows the amount of air expired from the lungs as a function of time.
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Below is a short explanation of the terms used in spirometry.
FVC (Forced Vital Capacity) -- This is the total volume of air expired after a full inspiration. Patients with obstructive lung disease usually have a normal or only slightly decreased vital capacity. Patients with restrictive lung disease have a decreased vital capacity.
FEV1 (Forced Expiratory Volume in 1 Second) -- This is the volume of air expired in the first second during maximal expiratory effort. The FEV1 is reduced in both obstructive and restrictive lung disease. The FEV1 is reduced in obstructive lung disease because of increased airway resistance. It is reduced in restrictive lung disease because of the low vital capacity.
FEV1/FVC -- This is the percentage of the vital capacity which is expired in the first second of maximal expiration. In healthy patients the FEV1/FVC is usually around 70%. In patients with obstructive lung disease FEV1/FVC decreases and can be as low as 20-30% in severe obstructive airway disease. Restrictive disorders have a near normal FEV1/FVC.
FEF25-75% (Forced Midexpiratory Flow Rate) -- This is the average rate of airflow during the midportion of the forced vital capacity. This is reduced in both obstructive and restrictive disorders.
DLCO (Diffusing Capacity of the Lung for Carbon Monoxide) -- Carbon monoxide can be used to measure the diffusing capacity of the lung. The diffusing capacity of the lung is decreased in parenchymal lung disease and COPD (especially emphysema) but is normal in asthma.
Pre-lab Questions: From: www.enchantedlearning.com/subjects/anatomy/lungs/label/index.shtml 1. What is a specialist of the respiratory system called? 2. An outward breath is called expiration, what is an inward breath called? 3. Which of these is not a section of the pharynx? a. Laryngopharynx b. oropharnx c. bronchopharynx d. nasopharynx 4. What is the medical term for Adam’s Apple?
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a. Epiglottis b. trachea c. glottis d. thyroid cartilage 5. What is the name for the membrane surrounding the lungs? a. Apex b. bronchi c. pleura d. lobes 6. What age group is the most vulnerable to respiratory syncytial virus? a. Infants b. seniors c. adults d. adolescents 7. What is an examination of the larynx, trachea and esophagus. a. Bronchoscopy b. laryngoscopy c. tracheostomy d. spirometry 8. Which of these is not an asthma preparation? a. Ventolin b. seldane c. singulair d. proventil 9. Which of these is the smallest part of the bronchial tree? a. Pleura b. trachea c. bronchus d. bronchioles 10. What part of the body is also known as the thoracic cavity?
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Experiments 1) http://www.medicine.mcgill.ca/physio/vlab/exercise/protocol_new.htm 2) Turn on respirometer and fill out the Quick Patient Information. Such as Male/Female, daily exercise routine, smoker, etc.
- Next select 1 – Spirometry, select 1 again – Expiratory Relaxed Vital Capacity. When the machine reads “Blow Now”, take a deep breath and exhale at a slow consistent rate into the mouth piece.
- Select 2 when Done. Forced Vital Capacity Test will begin on the next screen. You will want to take a deep breath and then forcibly blow into the mouth piece. This will need to be repeated at least 3 times until the screen reads “Good Blow”.
- Now we can view our results from the report menu. - The final test from the Spirometry menu is Inspiratory Relaxed Vital Capacity, select 2.
After exhaling completely, breathe into the mouthpiece at a slow and steady rate, when finished select Done.
- Forced Vital Capacity will pop up again, and once more you will complete at least 3 forced exhales in a row until the screen reads Good Blow.
- View results. FVC = Forced Vital Capacity FEV = Forced Expiratory Volume FEV/FVC = ratio of percentage of total volume (FVC) in a given amount of time
(derived from FEV) IC = Inspiratory Capacity Students will perform this before and after exercising (going up and down three flights three times). Afterwards each patient will perform these tests again to compare before and after results. Try to make homogeneous groups: i.e. women that do or don’t do exercise, that smoke or not, etc. Same for men. Notice any trends and decide if breathing improved or not. Find out what should be your respiratory capacity at: http://www.micromedical.co.uk/services/predict/default.asp
Laboratory Handout Respiratory Air Flow and Volume
Page 1 of 5
Introduction In this laboratory, you will be introduced to spirometry as a technique for recording respiratory variables and you will analyze a recording to derive respiratory parameters. You will examine lung volumes and capacities, as well as the basic tests of pulmonary function and simulate an airway restriction.
Background Gas exchange between air and blood occurs in the alveolar air sacs. The efficiency of gas exchange is dependent on ventilation; cyclical breathing movements alternately inflate and deflate the alveolar air sacs (see Figure 1). Inspiration provides the alveoli with some fresh atmospheric air and expiration removes some of the stale air, which has reduced oxygen and increased carbon dioxide concentrations.
Figure 1. A schematic diagram of the human respiratory system.
Spirometry is becoming more and more important, as respiratory diseases are increasing word wide. Spirometry is the method of choice for a fast and reliable screening of patients suspected of having Chronic Obstructive Pulmonary Disease (COPD). COPD is the 12th leading cause of death worldwide and the 5th leading cause in Western countries. Studies suggest COPD could climb to be the 3rd leading killer by 2020. Most COPD cases are completely avoidable; 85-90% of cases are caused by tobacco smoking.
Laboratory Handout Respiratory Air Flow and Volume
Page 2 of 5
Many important aspects of lung function can be determined by measuring airflow and the corresponding changes in lung volume. In the past, this was commonly done by breathing into a bell spirometer, in which the level of a floating bell tank gave a measure of changes in lung volume. Flow, F, was then calculated from the slope (rate of change) of the volume, V:
F = dVdt
Equation 1
More conveniently, airflow can be measured directly with a pneumotachometer (from Greek roots meaning “breath speed measuring device”). The PowerLab pneumotachometer arrangement is shown in Figure 2.
Figure 2. The PowerLab pneumotachometer.
Several types of flow measuring devices are available and each type has advantages and disadvantages. The flow head you will use today is a “Lilly” type that measures the difference in pressure either side of a mesh membrane with known resistance. This resistance gives rise to a small pressure difference proportional to flow rate. Two small plastic tubes transmit this pressure difference to the Spirometer Pod, where a transducer converts the pressure signal into a changing voltage that is recorded by the PowerLab and displayed in LabTutor. The volume, V, is then calculated as the integral of flow:
V = F dt∫ Equation 2
Laboratory Handout Respiratory Air Flow and Volume
Page 3 of 5
This integration represents a summation over time; the volume traces that you will see in LabTutor during the experiment are obtained by adding successive sampled values of the flow signal and scaling the sum appropriately. The integral is initialized to zero every time a recording is started. A complication in the volume measurement is caused by the difference in air temperature between the Spirometer Pod (at ambient temperature) and the air exhaled from the lungs (at body temperature). The volume of gas expands with warming, therefore the air volume expired from the lungs will be slightly greater than that inspired. Thus a volume trace, as calculated by integration of flow, drifts in the expiratory direction. To reduce the drift, the flow has to be integrated separately during inspiration and expiration, with the inspiratory volume being corrected by a factor related to the BTPS factor (body temperature, atmospheric pressure, saturated with water vapor). The LabTutor software makes this correction. Spirometry allows many components of pulmonary function (see Figure 3 below) to be visualized, measured and calculated. Respiration consists of repeated cycles of inspiration followed by expiration. During the respiratory cycle, a specific volume of air is drawn into and then expired from the lungs; this volume is the Tidal Volume (VT). In normal ventilation, the breathing frequency (ƒ) is approximately 15 respiratory cycles per minute. This value varies with the level of activity. The product of ƒ and VT is the Expired Minute Volume ( EV ), the amount of air exhaled in one minute of breathing. This parameter also changes according to the level of activity. Note that the volume of air remaining in the lungs after a full expiration, residual volume (RV), cannot be measured by spirometry as a volunteer is unable to exhale any further.
Laboratory Handout Respiratory Air Flow and Volume
Page 4 of 5
Figure 3. Lung volumes and capacities.
Terms that you should be familiar with before coming to class.
Term Abbreviation / Symbol Units Respiratory Rate RR breaths / min (BPM) Expired Minute Volume =
E TV RR x V L/min Lung Volumes Tidal Volume VT L Inspiratory Reserve Volume IRV L Expiratory Reserve Volume ERV L Residual Volume RV (predicted) L Lung Capacities Inspiratory Capacity IC = VT + IRV L Expiratory Capacity EC = VT + ERV L Vital Capacity VC = IRV + ERV + VT L Functional Residual Capacity FRC = ERV + RV L Total Lung Capacity TLC = VC + RV L Pulmonary function tests Peak Inspiratory Flow PIF L/min Peak Expiratory Flow PEF L/min Forced Vital Capacity FVC L Forced Expired Volume in one second FEV1 L % FVC expired in one second FEV1/FVC x 100
Laboratory Handout Respiratory Air Flow and Volume
Page 5 of 5
What you will do in the laboratory There are five exercises that you will complete during this Lab. 1. Becoming familiar with the equipment. In this exercise, you will learn the
principles of spirometry, and how integration of the flow signal gives a volume.
2. Lung volumes and capacities. Here you will examine the respiratory cycle and measure changes in flow and volume.
3. Pulmonary function tests. Here you will measure parameters of forced expiration that are used in evaluating pulmonary function.
4. Simulating an airway restriction. In this exercise, you will simulate an airway restriction.
5. Variability amongst group members. In this exercise, you will compare the parameters of forced expiration measured in different students.
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Susie Cute Before Exercise After exercise After three minutes
FEV1/FVC
FVC
Athlete Before Exercise After exercise After three minutes
FEV1/FVC
FVC
Video-game addict Before Exercise After exercise After three minutes
FEV1/FVC
FVC
Before Immediately After one minute After 3 minutes
Trained student Poorly trained student
After smoking/coffee 2 min after 3 min after 4 min after
FVC
Post-Lab Questions:
1. Would you expect someone who regularly exercises to have improved breathing after exercising compared to those who do not exercise regularly?
2. Explain why breathing improved with exercise? 3. Why did the person who exercises not improve?
11.
DIGESTION
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11. DIGESTION
Objective: 1. The purpose of this lab is to learn about digestive enzymes and their optimal
conditions.
I. Gastrointestinal system A. Oral cavity B. Esophagus is lined with stratified squamous epithelium, and uses stratified and smooth muscles for contractions.
C. Stomach made of two glands 1. Gastric Gland are the cells that line the folds of the mucosa
a.) goblet cells: secrete mucus b.) Parietal cells to secrete H-Cl c.) chief cells secrete pepsinogen
2. Pyloric gland a.) enterochromaffin-like cells secrete histamine b.) G cells secrete gastrin c.) D cells secrete somastatin
D. Small Intestine 1. divided into three regions a.) Duodenum b.) Jejunum
d.) Ileum 2. Contains microvilli, villi, and plicae circulares to increase the surface area of the
intestines, which maximizes the rate of digestive product absorption 3. Digestive enzymes for food hydrolysis are fixed to the cell membrane 4. Epithelium secretes many digestive enzymes
a.) secretin: stimulates water and bicarbonate secretion in pancreatic juice, and potentiates actions of CCK on the pancreas
b.) CCK (cholecystokinin): Stimulates contraction of the gallbladder, secretion of pancreatic juice enzymes, inhibits gastric motility and secretion, maintains the structure of exocrine pancreas
c.) Gastric inhibitory peptide: inhibits gastric motility and secretion, and stimulates secretion of insulin from pancreatic inlets
E. Large Intestine (colon) receives waste products from the small intestines
F. Liver Secretes bile to emulsify fats, sends it to the gallbladder, where it is stored and concentrated, it also has phagocytic cells which modify the blood
G. Pancreas
Is a double gland: endocrine and exocrine gland: tissues secrete pancreatic juices to be carried to the duodenum Islands of endocrine cells AKA Islets of Langerhans:
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a.) alpha cells secrete glucagon b.) beta cells secrete insulin
II. Digestion
A. Carbohydrates Carbohydrate digestion begins in the mouth, with the mixing of saliva, containing salivary amylase, to hydrolyze the long chains into shorter polysaccharide chains, and then into maltose a glucose disaccharide B. Protein Protein digestion takes place in the stomach. First they are coagulated due to the high acidity, allowing pepsin to begin digestion. Digestion is completed in the small intestines by proteolytic enzymes, which hydrolyze proteins into amino acids. C. Fat The major digestion of fats occurs in the small intestines with the help of pancreatic and intestinal lipase, and bile. It is the bile salts that emulsifies the large fat drops into little fat droplets. This allows them to be broken down into monoglycerides and fatty acids, which form micelle and are absorbed into the intestinal epithelium.
III. Digestive enzymes Amylase Pepsin Trypsin Chymotrypsin Lipase V. Hormones Gastrin: is the major physiological regulator of gastric acid secretion. http://www.vivo.colostate.edu/hbooks/pathphys/endocrine/gi/gastrin.html Ghrelin: increases appetite: http://www.vivo.colostate.edu/hbooks/pathphys/endocrine/gi/ghrelin.html CCK: involved in appetite decrease. Leptin: regulates body weight, metabolism and reproductive function. But obese people tend to have high levels of leptin. http://www.vivo.colostate.edu/hbooks/pathphys/endocrine/bodyweight/leptin.html VI. Neurotransmitters Serotonin is released during digestion that is partly why you feel sleepy after a big meal.
Pre-Lab Questions From: www.funtrivia.com 1. What is the study of the gastrointestinal system? 2. What is the GI tract also known as? 3. How many pairs of salivary glands are there? 4. What is the beginning of the large intestine called? 5. What is the portion of the digestive tract between the stomach and large intestine? 6. What age group is the most likely to develop pyloric stenosis?
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7. What is the medical term for vomiting? 8. What is the removal of part or all of the stomach? 9. Are the teeth a part of the gastrointestinal system? 10. Which cavity starts the GI system? 11. Wavelike motions that propel food through the GI system are called what? 12. Whe entering the stomach, what part does the food pass by first? 13. What nutrient does amylase work on? 14. Which organ is mainly used for storage? 15. Which section of the large intestine is least likely to develop cancer? 16. Name one of the five gases that account for 99% of intestinal gas? 17. After the watery saliva dissolves the food, the food is then stuck together with mucoid made by the salivary glands. What is the ball of food called? 18. Which of the palates prevent food from entering the nasal cavity? 19. The tongue has skeletal muscles that are labeled extrinsic and intrinsic. How does the extrinsic muscle help the tongue during digestion? 20. The tongue has four taste zones. Where is the bitter zone located? 21. True or False: the lifespan of a taste bud is one year? 22. Which of the following is broken down in the mouth? a. Protein b. starch c. fats
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Experiments
Each group will need approx 16 test tubes.
Starch/Amylase 1. Label four clean test tubes 1-4. (label an additonal four tubes as 1a, 2a, 3a, and 4a for later) 2. Obtain 5 ml of amylase solution by spitting into a clean test tube. 3. Add 3.0 ml of distilled water to tube 1. 4. Add 3.0 ml of amylase to tubes 2 and 3. Add one drop of hydrochloric acid to tube 3. 5. Boil the remaining amylase solution in a Pyrex test tube, the add 3.0 ml of this boiled
amylase to tube 4. 6. Add 5.0 ml of cooked 1% starch solution to each tube (1-4). 7. Allow the tubes to incubate for at least 1 hr. in a 37°C water bath. 8. Divide the contents of each sample in half by pouring into four new test tubes (1a-4a). 9. Test one set of solutions for starch by adding a few drops of Lugol’s soln. (Positive =
purple/black color) 10. Test the other set of solutions for reducing sugars in the following way: (a) Add 5.0 ml of Benedict’s reagent to each of the four test tubes and immerse them in a rapidly boiling water bath for 2 minutes. (b) remove the tubes from the boiling water with a test-tube clamp and rate the amount of reducing sugar present according to the scale on your lab report. Protein/pepsin 1. Label five test tubes 1-5 2. Using a razor blade cut 5 very thin slices of egg white (aprox. 2 cm2) and place one in each
test tube (1-5) 3. Add one drop of distilled water to tube 1. Add one drop of concentrated HCl to tubes 2-4,
add one drop of concentrated (10 N) NaOH to tube 5. 4. Add 5.0 ml of pepsin solution to tubes 1, 2, 3, and 5. Add 5.0 ml distilled water to tube 4. 5. Place tubes 1, 2, 4 and 5 in a 37°C water bath. Place tube 3 in the freezer. 6. After 1 hr. remove the tubes from the water bath (allow tube #3 to thaw) and record the
appearance of each egg white in your lab report. Fat/lipase 1. Obtain 3 test tubes and label them 1-3 2. Add the following to the indicated test tubes. 1- 3.0 ml cream + 5.0 ml DI H2O + few grains of bile salts. 2- 3.0 ml cream + 5.0 ml pancreatin solution. 3- 3.0 ml cream + 5.0 ml pancreatin solution + few grains of bile salts. 3. Using pH paper, check the pH of each tube. 4. Incubate the tubes in a 37°C water bath for 1 hr. then check the pH of each tube and 5 record your results in your lab report.
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Name__________________
Digestion
Starch/Amylase Contents before incubation Starch after incubation Maltose after incubation 1. Starch + distilled water 2. Starch + amylase 3. Starch + amylase + HCl 4. Starch + boiled saliva Use the following scale to rate the amount of reducing sugars present after the addition of Lugol’s (iodine) and Benedict’s reagent Solution color rating Blue-Black - (unhydrolyzed polysaccharides i.e. starch) Green + Yellow ++ Orange +++ Red ++++ (hydrolyzed reducing sugars; maltose, glucose, etc.) Protein/pepsin Incubation conditions Appearance of Egg white after incubation 1. Protein + pepsin @ 37°C 2. Protein + pepsin + acid @ 37°C 3. Protein + pepsin + acid @ 0°C 4. Protein + acid @ 37°C 5. Protein + pepsin + NaOH @ 37°C Fat/lipase Incubation conditions Initial pH (time 0) Final pH (time 1 hr.) 1. Cream + bile salts 2. Cream + lipase 3. Cream + bile salts + lipase
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1. Which tubes contained the most starch following incubation, which tubes contained the most hydrolyzed sugars? Based on these observations, which conditions favor the chemical breakdown of polysaccharides?
2. What effect does cooking have on enzyme activity? Explain why this effect is produced. 3. Briefly explain how temperature plays a role in digestion (hint: why is the water bath set at
37°C). 4. What role does the stomach play in digestion i.e. what is its function? 5. Explain why fat digestion effects the pH of the solution. What is the function of bile salts in
fat digestion? 6. How does the pancreas help neutralize the acidic chyme produced by the stomach?
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12. REGULATION OF METABOLISM
Experiments
Here you will do the experiments described in PowerLab Tutor for regulation of Metabolism and fitness.
12.
REGULATION OF METABOLISM
Student Handout
Aerobic Fitness Testing
Page 1 of 5 ©2007 ADInstruments
Introduction In this laboratory, you will become familiar with measuring maximal rate of oxygen consumption. The exercise involves measuring a participant’s heart rate (bpm), respiratory rate (bpm), and the fraction CO2 and O2 expired. You will also assess changes in work rate intensity to the physiological measure of the participant.
Background
A commonly used method for determining aerobic fitness is the VO2 max test. This measures an individual's capacity to utilize oxygen. A high VO2 max indicates than an individual is better equipped to meet the oxygen demands of the body during exercise. In this laboratory, two individuals will perform the VO2 max test. This test involves incrementally increasing exercise intensity (work rate) until the participants reach volitional exhaustion, or they reach their age predicted maximum heart rate.
Aerobic performance relates to cardiac function, although VO2 max can be specific to the mode of exercise through differences in the skeletal muscles involved. For example, an individual can obtain different VO2 max results in swimming and running, because of the different muscles used. VO2 max is determined through the functional capacity and integration of systems that supply, transport, deliver and use oxygen. These systems include:
• Pulmonary ventilation • Hemoglobin • Blood volume and cardiac output • Aerobic metabolism
VO2 max can be defined in absolute (L/min) or relative (mL/kg/min) terms. Absolute VO2 max refers to the amount of oxygen used by the entire body and is important to non-weight bearing sports i.e. cycling and rowing. Relative VO2 max allows comparisons between people by taking into account body weight (kg). It is important in weight-bearing sports i.e. running and soccer. Training causes physiological adaptations in the body, leading to improved exercise performance and aerobic power through:
• Enhancement of oxygen transport and use at a local level (within the trained muscles)
• Greater ability to generate adenosine tri-phosphate (ATP) aerobically • Higher regional blood flow (from better distribution of cardiac output or increased
microcirculation, or a combination of both).
Student Handout
Aerobic Fitness Testing
Page 2 of 5 ©2007 ADInstruments
The Energy Systems
The body utilizes energy from both aerobic and anaerobic systems. Three overlapping systems supply the energy required for the body to perform daily activities and additional work:
• ATP-Phosphocreatine "Phosphagen" (Anaerobic) • Anaerobic Glycolytic (This is actually the first stage of Aerobic metabolism,
however it does not involve O2) • Aerobic Metabolism (glycolytic and lipolytic)
Figure 1. The relative utilization of energy-transfer systems for different durations of exercise.
The crossover between these three energy systems allows a continual source of energy. The energy derived from these systems differs in rate and capacity, as shown in Table 1.
Table 1. The maximum energy-transfer rate and the amount of stored energy typically available for each energy system.
System Maximal Power (moles of ATP per minute)
Maximal Capacity (moles of ATP available)
Phosphagen (ATP-PCr) 3.6 0.7 Anaerobic Glycolysis 1.6 1.2
Aerobic (if from glycogen only) 1 90
Student Handout
Aerobic Fitness Testing
Page 3 of 5 ©2007 ADInstruments
The human body has energy in many forms:
• Adenosine Tri-phosphate (ATP) • Creatine Phosphate, Phosphocreatine • Glucose (preferred energy source of the central nervous system) • Glycogen • Fatty Acids (triglycerides) • Amino Acids (protein)
Gas Exchange in the Lungs
Gas exchange between air and blood occurs in the alveolar air sacs of the lungs. The efficiency of gas exchange is dependent on ventilation; cyclical breathing movements that alternately inflate and deflate the alveolar air sacs. Inspiration draws air into the alveoli, where the oxygen is transferred to the blood and exchanged with carbon dioxide. Expiration removes the stale air, which contains increased carbon dioxide and reduced oxygen concentrations.
Metabolism and Energy Storage
As energy yielding molecules (carbohydrate and fats) are metabolized to generate ATP, oxygen consumption increases. Using spirometry and gas analysis techniques, the rate of oxygen (O2) consumption and carbon dioxide production (CO2) can be measured. The ratio between the VCO2 and the VO2 is called the respiratory exchange ratio (RER). Values less-than 1.0 indicate aerobic metabolism (CO2 production equal to or less than O2 consumption), whereas values greater-than 1.0 indicate that anaerobic metabolism is involved. Because the oxygen to carbon dioxide ratio is different for carbohydrate and lipid metabolism, the RER provides an indication of the predominant substrate being metabolized at a particular time during exercise.
Location of the Energy Systems
Cytosol: The phosphagen system and anaerobic glycolysis are located in the cytosol. The fuels used are creatine phosphate, for the phosphagen system, along with glucose and glycogen for anaerobic glycolysis. Mitochondria: The final stage of aerobic catabolism of carbohydrate, lipid and protein takes place in the mitochondria.
Factors influencing VO2max
Aerobic Training affects the utilization of oxygen throughout the human body. Many of the physiological and metabolic adaptations that occur due to aerobic training are independent of age, ethnic group and gender.
Student Handout
Aerobic Fitness Testing
Page 4 of 5 ©2007 ADInstruments
Changes that may occur with Aerobic Training
Adaptations Increase Decrease
Metabolic
Oxidative enzymes Oxidative capacity Mitochondria size Mitochondria number Individual muscle fiber - aerobic power
Hypertrophy slow twitch)
Cardiovascular
Heart Volume Heart Rate Heart Mass Requirements of Blood flow Size and thickness of left ventricular cavity Diastolic Blood Pressure
Plasma volume Systolic Blood Pressure Stroke volume End-diastolic volume O2 transport/delivery Circulatory reserve VO2 max Cardiac Output O2 extraction Improved O2 usage in the muscle Cross-sectional area of arteries, veins, capillaries
Pulmonary
Ventilation (maximal exercise) O2 cost of breathing Tidal Volume Respiratory rate Time to fatigue Ventilatory muscles endurance
Other
Fat free mass Body Mass Ability to off-load heat in warm environments Body Fat
Psychological state (?) improved
Other VO2 max Tests
There are other tests used to estimate VO2 max such as the Beep test, the Balke 15 minute Run, the Cooper 12 minute run and the Rockport test. Outside of the laboratory setting, some of these may be more feasible and appropriate due to time and resource constraints.
Student Handout
Aerobic Fitness Testing
Page 5 of 5 ©2007 ADInstruments
What you will do in the laboratory There are 3 exercises that you will complete during this Lab. 1. VO2max test. Two volunteers from your laboratory group will perform a continuous
exercise bout of increasing intensity every minute until exhaustion.
2. Heart rate, respiratory rate, volume of air expired, fraction CO2 and O2. These variables will be measured every minute of the experiment, before the next intensity.
3. Ventilatory responses and RER. Using the measured variables in the experiment, you will determine these, and compare the changes seen at different exercise intensities within the same individual and between individuals.
Student Handout
Cardiorespiratory Effects of Exercise
Page 1 of 9 ©2007 ADInstruments
Introduction In this laboratory, you will become familiar with auscultation (listening to the sounds of the body) and the measurement of blood pressure. You will also assess changes in physiological measures such as heart rate and respiratory rate from a volunteer during light and heavy exercise and describe changes in ECG intervals with heart rate changes.
Background
The cardiorespiratory system is directly responsible for distributing blood around the human body. The lungs and the heart work together, to re-oxygenate blood by pumping blood from the venous system into the pulmonary circulation. Here, carbon dioxide diffuses out of the blood and oxygen diffuses into it. It is then transferred into the systemic system through the heart. For this to occur, the heart and lungs make complex adjusts using internal and external cues. During exercise, the adjustments made by the cardiorespiratory system become much more pronounced.
Blood Pressure
Arterial blood pressure is determined by the balance between the cardiac output and the peripheral resistance. Arterioles are the major contributor to the peripheral resistance. In simplistic terms, the systolic pressure reflects the cardiac output while the diastolic pressure is determined by the peripheral resistance. During mild to moderate exercise, the increase in cardiac output is greater than overall vasodilation, and both systolic and diastolic blood pressure tend to increase. In moderate to severe exercise, vasodilation in the exercising muscle, together with some vasodilation in the skin to enhance heat loss, results in an increase in systolic pressure accompanied by a decrease in diastolic pressure. Thus the pulse pressure (the difference between the systolic and diastolic pressures) widens.
Figure 1. The formula to work out the mean arterial blood pressure at rest.
Determining (Figure 1) the mean arterial blood pressure (MABP) of an individual during rest gives an insight to the mean pressure in the arteries at a given time. Figure 2 shows the cardiac cycle, and the actual events occurring that give rise to
Student Handout
Cardiorespiratory Effects of Exercise
Page 2 of 9 ©2007 ADInstruments
systolic and diastolic pressures. Systolic pressure refers to the contraction of the heart's chambers; pushing blood out into the arteries this is also known as a heart beat. Diastolic pressure is measured when the heart is relaxed and the compartments are being filled with blood between heart beats. The amount of time spent in diastole is far greater than systole. During exercise the 'filling' time of the heart’s chambers is reduced, as heart rate increases, to increase the cardiac output. The calculation of mean arterial blood pressure becomes less accurate during exercise, as changes in heart rate are not accounted for in the formula.
Figure 2. The cardiac cycle.
Control of the arterial system
The arterial system functions as a pressure reservoir. Blood enters via the heart and exits to the venous system through the capillaries. Signals from the autonomic nervous system control the tone of smooth muscle sphincters around the arterioles. In this way, the autonomic nervous system controls the distribution of blood to the various organs in the body. The distribution of blood that flows to a particular organ is influenced by local conditions. If cells require more arterial
Student Handout
Cardiorespiratory Effects of Exercise
Page 3 of 9 ©2007 ADInstruments
blood-due to, say, a decline in pH or oxygen levels, or an increase in carbon dioxide levels-smooth muscle sphincters open to permit blood to enter the particular capillary beds.
The distribution of blood to an organ when a person is at rest may be very different from that seen during exercise. For example, the blood flow to the gut and kidneys, which together normally account for about 50% of the resting blood flow, decreases appreciably during exercise, whereas blood flow to the exercising skeletal muscles increases dramatically. The distribution of blood is controlled through blood pressure changes that arise from increases in cardiac output.
Figure 3. Changes in organ blood flow between rest and exercise.
Cardiac Output
The volume of blood ejected into circulation each minute by the heart, the cardiac output (CO), is the product of the heart rate (beats/min) (HR) and the stroke
Student Handout
Cardiorespiratory Effects of Exercise
Page 4 of 9 ©2007 ADInstruments
volume (liters/beat) (SV), that is, the volume of blood ejected during each beat. In humans, CO = HR x SV = 70 x 0.07 ~ 5.0 liters/min.
The mammalian nervous system controls heart rate via the autonomic nerves. Stimulation of sympathetic nerves increases the heart rate, while stimulation of the parasympathetic nerve supplying the heart, the vagus nerve, decreases the rate. At rest, the vagal effect predominates (vagal tone), and the heart beats more slowly than it would in the absence of any autonomic activity. During exercise, vagal activity diminishes and sympathetic activity increases. This, together with increased levels of circulating epinephrine, results in increased heart rate.
Stroke volume at rest is appreciably higher, and heart rate lower, in very fit individuals. It is influenced by a variety of factors including the volume of blood returning to the heart (venous return), sympathetic nerve activity and levels of circulating epinephrine. Initially, during exercise, these factors all increase, and stroke volume is thus increased. However, the increase in heart rate also decreases ventricular filling time and thus limits the capacity for increased stroke volume. Although initially stroke volume may increase up to 1.5 fold, once the level of exercise exceeds about 50% of the individual's capacity, there is little if any further increase in stroke volume. Only increasing heart rate can then increase cardiac output further.
Electrical activity of the heart during exercise
An increase in heart rate corresponds to a shortening of the cardiac cycle (RR interval decreases). Most of this shortening occurs in the TP interval. The QT interval also shortens, but only slightly. The regular pattern of peaks during one cardiac cycle is shown in Figure 4.
13.
RENAL PHYSIOLOGY
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13. RENAL PHYSIOLOGY
Objective: 1. The purpose of this lab is to learn about your own renal physiology. 4. Learn about effects of food or drinks on urine contents.
I. Anatomy of the kidneys
A. Renal vein and artery support the kidney's blood flow B. Renal pelvis collects urine from the collecting ducts C. Renal cortex (proximal and distal tubules) D. Renal Medulla (Loop of Henle and collecting duct) E. Nephrons (1 million per kidney): removes fluid using colloidal and hydrostatic
pressures
II. Functions of the kidneys
A. responsible for eliminating the waste products od metabolism B. responsible for retaining molecules essential for normal body function C. Maintaining a constant internal environment
electrolytes, fluid, and acid-base balances
III. Hormones A. Anti-diuretic hormone (ADH) is released by the post. pituitary
1. release is stimulated by the hypothalamus (osmoreceptors), which are stimulated by an increase in osmotic pressure during periods of dehydration
2. Release promotes the re-absorption of water from the renal tubules resulting in water retention and concentrated urea.
3. release is blocks by alcohol, and you get dehydrated B. Aldosterone is secreted by the cortex of the adrenal gland
1. Release is stimulated by a rise in blood K, and a drop in blood Na 2. Promotes the re-absorption of Na into the blood in exchange for K
C. Renin is an enzyme that helps form angiotensin 1. this hormone increases the blood pressure (by vasoconstriction) 2. it stimulates the secretion of aldosterone
D. Erythropoietin For better understanding go to:: http://www.sumanasinc.com/webcontent/animations/content/kidney.html Pre-Lab Questions 1. Which of the following is not a part of the kidney?
a. Glomerulus b. the trigone c. Bowman’s Capasule d. Loop of Henle 2. Which of the following can cause kidney failure?
a. Bell’s Palsy b. nystagmus c. Diabetes Mellitys d. Choleithiasis 3. Which of the following values is used to monitory kidney function? a.White blood cell count b. HgbA1c c. ELISA d. 24 hr creatinine clearance 4. Where is a transplanted kidney placed in the recipient’s body?
a. The right or left lower abdomen b. under the diaphragm c. under the liver d. the upper back on the right side
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5. Which of the following specialties deals with kidney diseases? a. Endocrinologist b. Neurologist c. Nephrologist d. Hematologist
6. How many phases are there in the formation of urine? a. 6 b. 3 c. 2 d. 4
7. What is the tubular structure that filters the urine in the kidney? a. Calyx b. internal urethral sphincter c. nephron d. cortex
8. What age group is the most likely to develop vesicourethral reflux? a. Adolescents b. infants and children c. seniors d. middle age adults
9. What is the medical term for a kidney stone? a. Nephrolith b. uremia c. nephron d. cystitis
10. What is a blood test done to measure the urea, which indicates normal or abnormal kidney function?
a. IVP b. GFR c. BUN d. ESWL
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NAME:_________________
LAB REPORT
1. Each student will drink Pint of water at the beginning of class. 2. Students that will go to the restroom with their urinalysis stick and hold the strip under the flow of the urine. Take their reading from the indicators and measure their urine contents. 3. The TA should make a chart to show how long it takes for the students to urinate again after drinking the pint of water. 4. Some students can see if soda drinks will make a difference (i.e. will be more diuretic than plain water).
Urinalysis
Student A B C D E F
Glucose Level
Protein conc.
Ketones
Blood
White Blood Cells
pH
Color
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QUESTIONS: 1. Was there a sample that showed levels higher or lower than expected? 2. What was the longest time recorded before going to the bathroom? 3. What was the shortest time? If it was very short, what could be the reason for this quick
delivery? 4. Was there a gender difference? 5. Did drinking soda made a difference?
14.
REPRODUCTION
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14. REPRODUCTION
Objective: 1. The purpose of this lab is to learn about the female reproductive cycle.
SEE: www.FertilityMonitor.com http://www.my-fertility-monitor.com/info_pages.php/pages_id/5?osCsid Signs of Ovulation
What Are the Signs of Ovulation? Common Question! Your most fertile time of the month starts one to two days before you ovulate and lasts for three days after you ovulate. The process of ovulation is when your body releases egg(s) from your ovary and begins it's journey through your fallopian tubes. If the egg is fertilized and implants, you are then pregnant. Understanding the signs of ovulation will help you raise your chances at conceiving each month. So What Are the Signs?
~ Breast tenderness ~ Abdominal cramps or twinges ~ Increased vaginal discharge:
Soon after your menstrual cycle, you might notice a sticky or "tacky" vaginal secretion. Immediately prior to ovulation, most women usually detect increased vaginal secretions that are wet and slippery (similar to the consistency of raw egg white). Generally, your body produces the greatest amount of this type of vaginal discharge is on the day of ovulation. Immediately following the day of ovulation, your vaginal discharge gradually becomes thicker in consistency, and less is secreted.
~ Change in position and firmness of the cervix (ask your doctor how to detect cervix changes)
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When your cervical position rises within your body, the opening gets larger and feels soft to the touch, this is an indication of being at your most fertile time. This page will give you information on the different positions, the changes of the opening as well as the feel of your cervix during your monthly cycle.
~ Cervix is Low, Hard & Closed
After your menstrual period you will begin to start checking your cervical position. At this time the position of your cervix will be low within your body and easily reached with your fingertips. The opening to your cervix will be closed - feeling like a small slit or a tiny hole. The feel of your cervix will be rather hard to the touch. It will feel almost like touching the tip of your nose. During this phase (the first phase within your cycle) you are considered infertile.
~ Cervix is High, Soft & Open
Right before ovulation occurs the amount of estrogen increases within your body. This causes your cervix to rise. When checking your cervical position, you will notice that it will move from the lowest point to mid and then extremely high. At the highest point it may be difficult to reach your cervix with your fingertips. The opening of your cervix increases making the slit or tiny hole much larger. The feel of your cervix is much softer now almost like touching your bottom lip. This is an indication of your peak or most fertile time. The cervix will remain high until you ovulate - after which estrogen subsides and the hormone progesterone is released causing your cervix to return to its low. closed and hard position.
From: http://my-fertility-monitor.com/info_pages.php/pages_id/5?osCsid=\\\\\\
Can you “feel” ovulation happen? The most obvious outward sign of approaching ovulation is increasingly wet and slippery cervical fluid. In fact, it can be so abundant that you may notice a string of cervical fluid literally hang down when you use the toilet (yikes!). If you notice this, you should assume that ovulation is about to happen within a day or two. This is what is referred to as a primary fertility sign. Some women are lucky enough to notice other signs on a regular basis, all of which are useful in helping them to further understand their cycles. These signs are referred to as secondary fertility signs, because they do not necessarily occur in all women or in every cycle in individual women. An example of a secondary fertility sign is the sharp pain that women often feel right around ovulation, which is called mittelschmerz, or literally, “middle pain.” It is most likely caused by the egg bursting through the ovarian wall. Why don’t I ever have any dry days after my period ends? Women who tend to ovulate fairly early, and therefore have shorter cycles, often start
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producing estrogen right after their periods end, so they begin producing cervical fluid early in the cycle. So noticing cervical fluid immediately after your period ends usually signals that you’ll have an early ovulation with a short cycle. From: http://www.cyclesavvy.com/index.html For better understanding go to: http://www.sumanasinc.com/webcontent/animations/content/ovarianuterine.html
Student Handout
Cardiorespiratory Effects of Exercise
Page 5 of 9 ©2007 ADInstruments
Figure 4. A Wiggers' diagram showing the cardiac cycle and the events that are measured.
The components of the ECG can be correlated with the electrical activity of the atrial and ventricular muscle:
• the P-wave is produced by atrial depolarization • the QRS complex is produced by ventricular depolarization; atrial
repolarization also occurs during this time, but its contribution is insignificant
• the T-wave is produced by ventricular repolarization.
Student Handout
Cardiorespiratory Effects of Exercise
Page 6 of 9 ©2007 ADInstruments
Respiratory Air Flow and Volume
Gas exchange between air and blood occurs in the alveolar air sacs. The efficiency of gas exchange is dependent on ventilation; cyclical breathing movements alternately inflate and deflate the alveolar air sacs (see Figure 5). Inspiration provides the alveoli with some fresh atmospheric air and expiration removes some of the stale air, which has reduced oxygen and increased carbon dioxide concentrations.
Figure 5. A schematic diagram of the human respiratory system.
Lung volumes and capacities.
Respiration consists of repeated cycles of inspiration followed by expiration. During the respiratory cycle, a specific volume of air is drawn into and then expired from the lungs; this volume is the Tidal Volume (VT). In normal ventilation, the rate of breathing (breaths/minute or BPM) is approximately 15 respiratory cycles per minute. This value varies with the level of activity. The product of BPM and VT is the Expired Minute Volume, the amount of air exhaled
Student Handout
Cardiorespiratory Effects of Exercise
Page 7 of 9 ©2007 ADInstruments
in one minute of breathing. This parameter also changes according to the level of activity.
Figure 6: Lung volumes and capacities
Respiration during exercise
Both oxygen consumption and carbon dioxide production increase during exercise. Despite this, arterial gas composition remains remarkably constant. Exactly how this is achieved is still to be fully understood. Both tidal volume and respiratory rate increase, and a variety of factors are thought to contribute to this including increased central nervous drive, changes in arterial blood pH and possibly potassium concentration, and possibly alterations in the sensitivity of the carotid bodies to oxygen and carbon dioxide.
Student Handout
Cardiorespiratory Effects of Exercise
Page 8 of 9 ©2007 ADInstruments
Figure 7. Physiological changes that occur during exercise (adaptation of Bray et al.)
Student Handout
Cardiorespiratory Effects of Exercise
Page 9 of 9 ©2007 ADInstruments
What you will do in the laboratory There are 2 exercises that you will complete during this Lab. 1. Comparing Physiological Measures. You will measure volume of expired
air, respiratory rate, heart rate and blood pressure and compare their changes in 4 different conditions; resting, light exercise, heavy exercise and recovery.
2. Analyze changes in ECG. You will record ECG throughout the entire protocol and look its relationship with heart rate. Using the ECG trace, you will become familiar with the intervals that make up the cardiac cycle, and use the ECG trace to show the changes which occur.
15.
PEER EVALUATION
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15. PEER EVALUATION Speaker_______________________________________________Date___________________ Topic________________________________________________________________________ 1. Clarity: I understood............a) all b) most c) some d) very little e) none Comments_____________________________________________________________________ 2. Organization: The seminar seemed..................................... a) well organized throughout. b) generally well organized. c) occasionally organized. d) lacked organization. Comments_____________________________________________________________________ 3. Mannerisms: Did anything distract you from the presentation? Explain. a) vocalizations__________________________________________ b) gestures____________________________________________ c) visual aid problems_____________________________________ d) other______________________________________________ 4. Visual aids: Rank the visual aids (excellent, good, fair, poor, awful). Explain. a) clarity___________________________________________________ b) appropriateness____________________________________________ c) technical presentation______________________________________ 5. Final Evaluation: Overall, I felt the seminar was........................................... a) excellent b) good c) fair d) poor e) awful Comments___________________________________________________________________ ____________________________________________________________________________ Final Grade: Out of 100%, assign a grade you think this presentation is worthy of. Remember, if you give everyone 100%, I will only use my grade when figuring out the final score.
