Exercise 11- Animal Physiology:
Respiration and Circulatory Systems
Exercise 11- Overview
• Generate a hypothesis about the relationship between
ambient temperature and metabolic rate in ectotherms
• Design and conduct an experiment with crickets to test
this hypothesis
• Measure the human heart rate under different conditions
(e.g., resting, holding breath, face in water, after exercising,
final resting)
• Measure human blood pressure under different conditions
(e.g., initial resting, after exercising, final resting)
Do all animals need to regulate their
body temperature?
Thermoregulation vs. Thermoconformers
Homeotherms: (thermoregulators):
stable body temperatures.
Poikilotherms: (thermoconformers):
their body temperature changes with the
environment.
Ectotherms vs. Endotherms
Endotherms: rely on internal heat
produced by metabolically active organs
(liver, kidney, heart, brain, muscle)
Ectotherms: rely on environmental heat
sources.
What is the independent variable?
What is the dependent variable?
What is the effect of increasing ambient
temperature on oxygen consumption?
Can you explain the difference between
endotherms and ectotherms?
Gas Exchange- Physiologic Respiration
How could you measure metabolic rate in a cricket?
Physiologic Respiration: Spiracles
Metabolic activity and Crickets
Draw a graph of the expected relationship between
ambient temperature, body temperature and metabolic
activity for a cricket.
Equipment: crickets, environmental chamber, CO2 probe,
temperature probe.
8
Crickets Belong to the Order Orthoptera
OvipositorRudimentary wings
Acheta domesticus, commonly called the house cricket
Equipment
Temperature and Respiration
What is your testable hypothesis?
What are your dependent and independent variables?
How will you manipulate your independent variable?
How will you measure your dependent variable?
What variables do you need to control?
What is your unit of replication? Do you think using one cricket work?
What is your sample size? In other words, how many replicates do you need?
Can you ‘reuse’ crickets to increase your sample size?
Exercise 11- Overview
• Generate a hypothesis about the relationship between
ambient temperature and metabolic rate in ectotherms
• Design and conduct an experiment with crickets to test
this hypothesis
• Measure the human heart rate under different conditions
(e.g., resting, holding breath, face in water, after exercising,
final resting)
• Measure human blood pressure under different conditions
(e.g., initial resting, after exercising, final resting)
Circulatory System: Movement of blood cells
In vertebrates: a closed
circulatory system
Blood flows in two connected,
continuous circuits through the
body
What kind of circulatory
system does a crayfish have?
LUNG =
PULMONARY
CIRCUIT
BODY =
SYSTEMIC
CIRCUITVideo: https://www.youtube.com/watch?v=5tUWOF6wEnk
Cardiac Cycle: Moving the blood
Diastole = whole heart is relaxed.
Systole = heart contraction.
With each contraction, a wave of blood is pushed from the heart.
Can be felt as pulsations in arteries close to the skin surface, such as those in the wrist and neck.
Pulse Points
The pulse may be palpated in any place that allows an artery to be compressed against a
bone:
The neck (carotid artery)
On the inside of the elbow (brachial artery)
At the wrist (radial artery),
At the groin (femoral artery)
Behind the knee (popliteal artery)
Near the ankle joint (posterior tibial artery)
On foot (dorsalis pedis artery).
Take your pulse using the pulse point in
your neck.
Heart Rate (beats per minute)
Average = 70 bpm
Trained athlete = 50 bpm
Anxious/excited = 125 bpm
Faster rate: Tachycardia
Slower rate: Bradycardia
Irregular Rate: Arrhythmia
What will be the effect of holding your breath on your heart rate? Exercise? Immersing your face in really cold water?
The Mammalian Diving Response/Reflex
http://www.youtube.com/watch?v=nhd8Yr_u_18
Bradycardia: slowing down of heart rate
Peripheral vasoconstriction: restriction of circulation to vital capillary beds (brain & heart) circulation to muscles.
Do you think my daughter (an 11 year-old competitive swimmer) or me is
more likely to have the mammalian diving response?
Blood pressure
Blood Pressure
Category
Systolic
mm Hg (upper #)
Diastolic
mm Hg (lower #)
Normal less than 120 and less than 80
Prehypertension 120 – 139 or 80 – 89
High Blood Pressure
(Hypertension) Stage 1140 – 159 or 90 – 99
High Blood Pressure
(Hypertension) Stage 2160 or higher or 100 or higher
Hypertensive Crisis
(Emergency care needed)Higher than 180 or Higher than 110
Blood pressure at rest
Sphygmomanometer & stethoscope(Sphyg-mo-ma-nom-e-ter)
https://www.youtube.com/watch?v=VJrLHePNDQ4 https://www.youtube.com/watch?v=-LqKmrmaHsk
What Determines Resting Blood Pressure?
The exact causes of high blood pressure are not known,
but several factors and conditions may play a role in its
development, including:
• Smoking
• Being overweight
• Lack of physical activity
• Alcohol consumption
• Older age
• Genetics
What happens to your systolic
and diastolic pressure when you
exercise?
Exercise 11- Overview
• Generate a hypothesis about the relationship between
ambient temperature and metabolic rate in ectotherms
• Design and conduct an experiment with crickets to test
this hypothesis
• Measure the human heart rate under different conditions
(e.g., resting, holding breath, face in water, after exercising,
final resting)
• Measure human blood pressure under different conditions
(e.g., initial resting, after exercising, final resting)