A&P CH13

Question 1

vessel layers (inner to outer)

Answer 1

tunica interna
tunica media
tunica externa

Question 2

which are thicker - arteries or veins?

Answer 2

arteries, due to higher vascular pressure

Question 3

tunica interna comprise of…?

Answer 3

elastic fibers, need elasticity to respond to needs of body

Question 4

tunica media contains what? (3)

Answer 4

smooth muscle, collagen, elastic fibers

Question 5

what is a capillary bed?

Answer 5

interconnected network of capillaries

Question 6

factors affecting blood flow (4) and what is each

Answer 6

1. pressure (force behind flow)
2. resistance (force that opposes movement, higher in arteries)
3. viscosity (thickness of blood)
4. turbulence (smoothness of flow)

Question 7

what affects viscosity?

Answer 7

hydration levels, medications

Question 8

fastest flow where? slowest?

Answer 8

fastest = near center, slowest = nearest vessel walls

Question 9

3 factors affecting tissue blood flow

Answer 9

cardiac output, peripheral resistance, blood pressure

Question 10

def baroreceptor

Answer 10

responds to changes in blood pressure

Question 11

def chemoreceptor

Answer 11

respond to changes in chemical composition

Question 12

critical blood loss

Answer 12

20% or more

Question 13

2 divisions of circulatory system

Answer 13

pulmonary circuit (heart to lungs), systemic circuit (to body and back to heart)

Question 14

what is name for blood flow to brain?

Answer 14

circle of willis

Question 15

what is hepatic portal system?

Answer 15

blood flow going to liver first

Question 16

2 components necessary for fetal blood flow and why

Answer 16

foramen ovale and ductus arteriosis, allow blood to bypass pulmonary circuit in a fetus