Human Systems
Getting and delivering oxygenGetting food and removing wasteCommunication
Major Functions
Function 1: Getting and Delivering Oxygen
• Why???
One word: ENERGY!!!!
Remember: In Cell respiration oxygen is combined with glucose to make ATP and CO2 (waste)
How do we get the oxygen?
• Requires two systems: – Respiratory system: brings O2 into
the body– Circulatory system: delivers O2 to
EVERY single cell in your body
Evolution of the heart
• Fish– Two chambers– High pressure ONLY between ventricle and gills– Low oxygenated pressure = limited rapid activity
• Amphibians– Three chambers, 2 atria, 1 ventricle– Mixed blood in the ventricle– High pressure to lungs and body
Evolution of the Heart
• Some reptiles– Partial separation of ventricles– Increased efficiency of oxygen transport
• Mammals, birds and crocodiles– Four chambered heart– Two separate pumps (ventricles)– High pressure, oxygen rich blood to the body– RESULT: high activity levels possible
Processing the food we eat
• Why do we need food? – Reactants for cell respiration (energy)– Building blocks for new cells, tissues, etc. – Essential nutrients: minerals, vitamins, etc.
• What happens to materials we can’t use? – Stored for later– Excreted– Converted into something we can use
Two main systems involved:
• Digestive: Breaks down food into small molecules (monomers!) and absorb the nutrients into the blood stream for delivery
Two main systems involved: • Excretory: Maintain Homeostasis– internal balance of chemicals–Rids body of metabolic wastes•Wastes produced by body’s metabolism•Eg: Salts, Carbon Dioxide, Urea
• BUT how do we deliver the “good stuff”?
• Bile: produced in the liver and stored in the gall bladder; function- breaks down/ dissolves lipids
• HCl: stomach; function- unravels proteins• Sodium Bicarbonate: pancreas; function-
neutralizes acid• Amylase: salivary glands; function- breaks down
starch• Pepsin: stomach; function- breaks down proteins
Differences in Digestive Systems
• In animals that eat grass, a more complex system is needed to digest cellulose.
• Any system that processes cellulose (cows, termites) requires a digestive area that contains micro-organisms that break down the cellulose.
• Differences in what foods can be utilized affect how we can change our eating habits.
Excretion
Major Excretory Organs–Skin – water and salts–Lungs – CO2–Large intestines –
excess/indigestible solid food waste–Kidneys and associated organs –
Urea – liquid metabolic waste
Kidney Nephron
Cortex
Medulla
Renal artery
Renal vein
Ureter
To the bladder
Bowman’s capsule
GlomerulusCapillaries
Collecting duct
To the ureter
Loop of Henle
Artery
Vein
FiltrationMost filtration occurs in the glomerulus. Blood pressure forces water,
salt, glucose, amino acids, and urea into Bowman’s
capsule. Proteins and blood cells are too large to cross the membrane;
they remain in the blood. The fluid that enters the
renal tubules is called the filtrate.
ReabsorptionAs the filtrate flows through the renal
tubule, most of the water and nutrients are
reabsorbed into the blood. The
concentrated fluid that remains is called urine.
SecretionSubstances such as hydrogen ions are
transferred from the blood to the filtrate.
Communications In the Body
Two systems involved: 1.Nervous – Quick response, electrical
messages; short lived; Examples?
2.Endocrine – slow, longer term response, chemical messages (hormones); examples?
Nervous System
• Central Nervous System – Brain and spinal cord– Its main job is to get the information from the
body and send out instructions.
• Peripheral Nervous System– The peripheral nervous system is made up of all of
the nerves and the wiring. This system sends the messages from the brain to the rest of the body.
Job of Each Part of the Neuron
• Neurons have specialized extensions called dendrites and axons.
Dendrites bring information to the cell body and axons take information away from the cell body. The cell body (soma) contains the nucleus and cytoplasm
How do signals go from one neuron to the next
• Junction between to neurons – Axon of one cell Dendrite of the NEXT cell
Chemicals released from one neuron to “stimulate” the next are called neurotransmitters
What does the nervous system respond to?
• Stimuli
• Neurons are able to respond to stimuli (such as touch, sound, light, and so on), conduct impulses, and communicate with each other (and with other types of cells like muscle cells).
http://www.youtube.com/watch?v=i-NgGKSNiNw&feature=player_embedded
Brain
• Cerebrum – Frontal Lobe– Parietal Lobe– Temporal Lobe– Occipital Lobe
• Cerebellum• Brainstem– Medulla oblongata– Pons
Cerebrum
• Voluntary or conscious activities
– Outer surface – Cerebral Cortex (grey matter)• Processes information from sense organs• Controls body movements
– Inner surface – White matter (bundles of axons)
Cerebellum
• Location: Back lower area inside skull, near brainstem
• Coordination and balance, fine motor skills (grace and efficiency)
Brain Stem
• Connects brain to spinal cord• Two regions– Medulla– Pons
• Controls involuntary processes– Blood pressure, heartrate, breathing swallowing
Reflex Arc
• http://www.youtube.com/watch?v=Y5nj3ZfeYDQ&feature=related