Circulation

Question 1

function of the circulatory system?

Answer 1

bring nutrients to body cells and take away waste products

Question 2

3 types of blood vessels that the cardiovascular system has?

Answer 2

arteries (& arterioles), capillaries, veins (& venules)

Question 3

function of arteries?

Answer 3

• take blood away from the heart
• carry nutrients & blood high in O2 throughout body (except pulmonary artery)
• regulate BP by constriction (increase BP) and dilation (decrease BP)

Question 4

why don’t arteries carry nutrients and blood through the pulmonary arteries?

Answer 4

the blood being carried is high in O2, and pulmonary arteries carry high levels of CO2

Question 5

what allows stretching within the artery?

Answer 5

elastic fibers in inner arterial layer (endothelium)

Question 6

what is the function of arterioles?

Answer 6

regulate BP by contracting to increase BP (narrow to increase BP)

Question 7

what do capillaries join?

Answer 7

arterioles to venules

Question 8

describe the exchange that occurs in capillary beds

Answer 8

-O2 & nutrients (ex: glucose) diffuse OUT of capillary into tissue fluid surrounding cells.
Some H20 also leaves.
-wastes (ex: CO2) diffuse INTO capillary

Question 9

some H20 leaves the capillary, along with O2 and nutrients. where happens to the excess H20?

Answer 9

it is picked up by lymphatic cells

Question 10

what do sphincters do?

Answer 10

open or close capillary beds to shunt (move) blood from one body system to another

Question 11

what allows for the exchange of materials within the capillary beds?

Answer 11

very thin structure consisting of one layer of cells

Question 12

function of veins?

Answer 12

have valves to prevent the back flow of blood (allows blood to flow in only 1 direction)

Question 13

how do the veins allow blood flow?

Answer 13

by contraction of skeletal muscles

Question 14

how are veins formed?

Answer 14

venules drain capillary blood and join to form a vein

Question 15

difference b/t structure of arteries and veins?

Answer 15

veins have a thinner wall than arteries (less smooth muscle and connective tissue), but larger hole (bore) in center (veins have larger interior diameter)

Question 16

function of venules?

Answer 16

• transport deoxygenated blood to <3 and wastes away from tissues
• return blood from cap. beds to veins

Question 17

what are the 2 blood circuits in terrestrial vertebrates?

Answer 17

• pulmonary circuit

- systemic circuit

Question 18

difference b/t pulmonary and systemic circuit?

Answer 18

• pulmonary: (from right to left side) from heart to lungs and back
• circuit: (from left to right side) from heart to everywhere else and back

Question 19

internal structure of the heart

Answer 19

2 thin walled atria and 2 thick walled ventricles separated by a septum

Question 20

function of coronary arteries?

Answer 20

supply the heart muscle with oxygen and nutrient rich blood

Question 21

right atrium

Answer 21

receives deoxygenated blood from superior and inferior vena cava
-sends blood through atrioventricular valve to right ventricle

Question 22

atrioventricular valve

Answer 22

prevent blood from flowing back into right atrium from the right ventricle

Question 23

what do the chordae tendineae prevent?

Answer 23

(corrects)
- prevent atrioventricular valve from inverting by anchoring them to the walls of the ventricles
- prevent AV’s from opening in wrong direction

Question 24

right ventricle

Answer 24

receives blood from right atrium, and pumps deoxygenated blood to the lungs through pulmonary trunk and pulmonary arteries.
Must go through a semi-lunar valve