Download Hemo the Magnificent

Hemo the Magnificent
1. Hemo means __blood____ in Greek.
2. William Harvey (1628) observed the circulatory system and predicted capillaries.
3. The circulatory system is a system of arteries and veins.
4. Arteries carry oxygenated blood to the body.
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“red” blood
You can feel your pulse here
Have to remain open
Thick muscular walls because the force of blood is so great
5. Veins carry deoxygenated blood from the body to the heart
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“blue” blood
Have one-way valves
Muscles help push blood up
Have thinner walls so they can be squeezed and push blood back to the
heart
6. Heart has 4 chambers with one-way valves between the chambers
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pumps 1 quart of blood in 10 seconds
size of your fist
strongest muscle in your body
does more work than all other muscles combined
brain controls how fast the heart beats
7. There are two types of nerves that control how fast or slow the heart beats:
 Sympathetic nerve tells the heart to beat faster (example: exercise)
 Vagus nerve tells the heart to beat slower (example: rest)
8. Capillaries are microscopic
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One cell thick
work of blood is done here
gives off nutrients and oxygen
takes away wastes (garbage) and carbon dioxide
cells are generally no more than two cells away from a capillary
Red blood cells pass through in single file
RBC passage is controlled by a gatekeeper, a round muscle called a
sphincter muscle
9. Three main body functions/activities:
 Brain – thinking; always get a full supply of blood
 Muscles – moving; 2nd priority for survival
 Digestive system – eating
10. All three body functions cannot get all the blood they can use at the same
time
 There is not enough blood to supply all three body functions
 The brain decides where the blood goes
11. Brain cells have priority to get the blood
 Barostat is the pressure regulator in the neck
 Barostat maintains blood pressure in the brain
12. Chemical regulators
 Hormones
 Can control heart rate (example; when you are scared)
13. The smaller the animal, the faster the heart beats to maintain body heat
14. The larger the animal, the slower the heart beats
15. LUBB_DUBB is the sound of the heart
 Sound is caused by closing the valves
16. Lungs
 Supply oxygen to the blood
 Takes carbon dioxide out of the blood
17. Blood and Seawater
 Blood has the same composition as seawater
i. Blood has the same salts in approximately the same
percentages as seawater
ii. 88% of seawater salts are the same as our blood