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 too-

mechanical 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

To prevent infection and illness• What is the point?

• What is the first line of defense?Skin!• What are the main cell types and their jobs?Macrophages-eat invaders and interact with helper TsHelper T Cells-Tell others what to doB-cells-Make antibodies to tag invadersMemory B-cells-remember past invadersKiller 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, thyroid-metabolism, parathyroid-calcium, adrenal-adrenalin,

pancreas-blood glucose, testes-testosterone, ovaries-estrogen

• 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

• 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.

Excretory System

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) boneMarrow (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