Transcript After School Physiology review 2013

Physiology Overview
Respiratory System
• What is the point?
get oxygen to muscles and carbon dioxide out
• Where does gas exchange happen?
In the lungs-between alveoli (air sacs) and
capillaries (small blood vessels)
• What parts are involved, in order?
Nose, pharynx, larynx, trachea, bronchi, lungs
• What does the diaphragm do?
Contracts to bring air in, relaxes for air to go
out
• What is the epiglottis?
Flap that prevents food from going down
trachea (wind pipe)
Circulatory system
• What is the point?
To get oxygen and nutrients to all cells and wastes out
• What moves the blood around?
The heart pumps the blood through arteries to
capillaries, and returns via veins
• How many chambers does the heart have? What
are they called?
4-right atrium, right ventricle, left atrium, left ventricle
• What do valves do?
Prevent back flow
Digestive System
• What is the point?
To break down food and provide nutrients for the cells
• Where are complex sugars broken down?
In the mouth, and chewing breaks down food here toomechanical digestion
• What happens in the stomach?
Acids break down proteins
• What happens in the small intestine?
Where MOST nutrient absorption takes place, lipids are
broken down here
• What do the liver, gall bladder, and pancreas do?
Liver-make bile to break down fat, Gall bladder-store bile,
pancreas-make chemicals for digestion in small intestine
• What does the large intestine do?
Mostly absorb water
Immune system
• What is the point?
To prevent infection and illness
• What is the first line of defense?
Skin!
• What are the main cell types and their jobs?
Macrophages-eat invaders and interact with helper Ts
Helper T Cells-Tell others what to do
B-cells-Make antibodies to tag invaders
Memory B-cells-remember past invaders
Killer T Cells-kill tagged invaders
• How do vaccines work?
Inject coat of virus with antigens on it (no DNA), body makes
antibodies and memory B cells, so ready when get real virus
Nervous system
• What is the point?
For brain to interact with body and environment
• What are the cells called?
Neurons-sensory neurons, interneurons, motor neurons
• How do they work?
Stimulus hits dendrite, causes voltage gates ion channels to
open on axon, sodium goes into cell, changing gradient,
spreading signal down axon to synapse-goes to next cell
• What is a synapse?
Space between one neuron and the next.
Neurotransmitters (chemicals) carry the signal across
• What is a reflex?
Signal that goes to spin and directly to motor neuron,
no brain involved
Endocrine System
• What is the point?
Send chemical messages (hormones) to control body activities
• Which glands are involved?
Hypothalamus-regulate pituitary, pituitary-regulate
adrenals, thyroid, growth, ova and sperm, thyroidmetabolism, parathyroid-calcium, adrenal-adrenalin,
pancreas-blood glucose, testes-testosterone, ovariesestrogen
• How are they controlled?
Negative feedback loops-when a lot is made, the gland stops
making it, then too little, starts making it again-like with
glucose and insulin
Positive feedback-less common, production causes more
production-oxytocin and childbirth
Excretory System
• What is the point?
To get rid of wastes from metabolism
• What parts are involved?
Lungs (for CO2) Kidneys (urea)
• How does it work?
•Kidney has nephrons- is made of a Bowman’s capsule:
tubules and capillaries
• Fluid (filtrate) enters capsule
•fuid passes through the tubule of the nephron,
materials needed reabsorbed, remainder becomes
urine.
Skeletal/Muscular
• What is the point?
Structure and movement
• How are bodies organized from small to big?
Cells-tissues-organs-organ systems-organisms
• What are the parts of a bone?
Compact bone (outside), spongy bone (inside) bone
Marrow (where blood cells made), and blood vessels
• What are ligaments? Tendons?
Ligaments-connect bone to bone, tendons-bone to muscle
• What are the three types of muscles?
1. Smooth-organs, involuntary 2. Cardiac-heart,
involuntary 3. Striated-arms, legs, voluntary
• How do muscles contract?
Actin slides across mysoin using ATP and calcium