Chapter 10 - blood pressure

Question 0

F =

Answer 0

flow rate of blood through a vessel

Question 1

flow rate through a vessel is _________ to the pressure gradient and ________ to vascular resistance

Answer 1

directly proportional

inversely related

Question 2

delta P

Answer 2

pressure gradient difference

- the higher the delta P, the greater the F

Question 3

R =

Answer 3

resistance of blood vessels

- resistance is a measure of opposition of blood flow through a vessel

Question 4

three things that oppose flow of blood

Answer 4

blood viscosity
vessel length
vessel radius

Question 5

major determinant of resistance to flow is _______

Answer 5

vessel’s radius

Question 6

slight change in radius produces significant change in ______

Answer 6

blood flow

Question 7

arteries

Answer 7

carry blood away from heart to tissues

- specialized to serve as rapid-transit passageways for blood from heart to organs

Question 8

3 layers of arteries

Answer 8

tunica interna (inner - endothelium)
tunica media
tunica externa - outer

Question 9

arterial connective tissue contains: collagen fibers

Answer 9

provides tensile strength

Question 10

arterial connective tissue contains: elastin fibers

Answer 10

provide elasticity to arterial walls/compliance (rubber band bounce into shape analogy)

Question 11

due to large radius, arteries offer little ______ to blood flow

Answer 11

resistance

Question 12

arteries act as ________ to provide driving force for blood when heart is relaxing

Answer 12

pressure resovoir

Question 13

aterioles defined

Answer 13

smaller branches of arteries - deliver blood to organs

Question 14

arterioles: major ______ - due to smaller radius

Answer 14

resistance vessels

Question 15

vasoconstriction

Answer 15

narrowing of vessel/decrease radius

• smooth muscle (tunica media) contracts
• increase resistance
• decrease flow

Question 16

vasodilation

Answer 16

increase in vessel radius

• smooth muscle relaxes
• decrease resistance
• increase flow

Question 17

only blood supply to ______ remains constant

Answer 17

brain

Question 18

control of diameter: local metabolic changes

Answer 18

• higher metabolic activity = higher blood flow
• lower metabolic activity = lower blood flow
• vasodilate in response to: decrease O2, increase CO2, increase acid, increase K+, increase adenosine

Question 19

control of diameter: local vasoactive mediators

Answer 19

• endothelial cells release vasoactive paracrines to affect arteriole radius
• NO reduces intracellular Ca+ concentration in smooth muscle = vasodilation

Question 20

control of diameter: local physical influences on arteriolar radius

Answer 20

local application of heat and cold

• prevent swelling = cold
• opening up blood flow = hot
• shear stress - NO release

Question 21

control of diameter: sympathetic stimulation

Answer 21

• s.m. of arterioles richly innervated
• alpha 1 = excitatory
• increase activity = vasoconstrict
• decrease activity = vasodilate
• 1. establishes vascular tone
     
     2. regulate flow into organs and MAP

Question 22

control of diameter: histamine

Answer 22

vasodilation

Question 23

control of diameter: angiotension II

Answer 23

potent vasoconstrictor

Question 24

vascular tone

Answer 24

reflects the state of partial s.m. contraction to establish baseline resistance
- ex. severely allergic people to bee stings lose their vascular tone

Question 25

MAP = overall ____

Answer 25

BP