cardiovascular lecture 3

Question 1

_____ are the main transporters of O2 blood

Answer 1

arteries

Question 2

what is adjusted in arterioles to regulate blood flow

Answer 2

the diameter is adjusted

Question 3

artery walls are made up mainly of what

Answer 3

ELASTIC TISSUE and smooth muscle

Question 4

arteriole walls are made up mainly of what

Answer 4

elastic tissue and SMOOTH MUSCLE

Question 5

capillary walls are made up of what

Answer 5

1 layer of endothelial cells for diffusion

Question 6

pulses of pressure move through the vasculature and __________ with distance

Answer 6

decrease the pressure amplitude with distance (from the heart)

Question 7

what is compliance

Answer 7

the change in volume over the change in pressure

Question 8

what is the maximum arterial pressure called

Answer 8

systolic pressure (heart is contracting)

Question 9

what is the minimum arterial pressure called

Answer 9

diastolic pressure (heart is relaxed and filling with blood)

Question 10

the pulse pressure is calculated as the difference b/w….

Answer 10

the SP - DP

Question 11

Mean arterial pressure (MAP) is calculated as

Answer 11

DP + 1/3 (SP-DP). aka the diastolic pressure minus one third of the pulse pressure

Question 12

what allows the blood to keep moving in the arteries during diastole

Answer 12

the recoil of the arteries (a result of them being stretched out during the contraction)

Question 13

what is MAP defined as

Answer 13

the pressure driving blood into the tissues averaged over the cardiac cycle (mean pressure in your vasculature)

Question 14

how do you calculate relative blood flow to an organ

Answer 14

Flow= MAP/Resistance (resistance to that organ)

Question 15

what is resistance influenced by

Answer 15

the smooth muscle vasodilation and vasoconstriction in arterioles

Question 16

blood distribution to organs is adjusted by what

Answer 16

relaxation and contraction of arteriole smooth muscle

Question 17

intrinsic tone (which i think is the degree of constriction of b.v) is controlled via what 2 controls

Answer 17

• local (organ itself)

- extrinsic

Question 18

local control of organ blood flow is through what 2 mechanisms

Answer 18

1. active hyperemia

2. flow autoregulation

Question 19

what is active hyperemia

Answer 19

a mechanism of local control in which an organ’s increase in metabolic activity ultimately causes an increase in blood flow to that organ. (increase metabolic activity—> decrease O2, increase metabolites—> arteriole dilation–>increase flow to organ)

Question 20

what is flow autoregulation

Answer 20

a mechanism of local control in which an decrease in MAP in an organ ultimately causes restoration of normal blood flow to organ (decrease in MAP to an organ–> decrease in blood flow to organ–> decrease in O2, increase in metabolites, *decreased stimulation of stretch receptors in organ–> arteriole dilation–> restoration towards normal blood flow to organ)

Question 21

local control occurs in what 3 main organs

Answer 21

1. heart
2. active skeletal muscle
3. brain

Question 22

what is reactive hyperemia

Answer 22

(a type of flow autoregulation?) the reaction of an organ to cessation of blood flow (organ responds by increasing the blood flow to itself=hyperemia)…the heart does this during diastole

Question 23

what is extrinsic control of intrinsic tone

Answer 23

control of blood flow to organs via: sympathetic system, psymp system, hormones, noncholinergic/adrengergic neurons

Question 24

what are the hormones used for sympathetic extrinsic control

Answer 24

• norepinephrine (from the post-gang symp neurons)

- epinephrine (from the adrenal medulla)

Question 25

sympathetic stimulation of alpha receptors causes

Answer 25

vasoconstriction to decrease blood flow to a location

Question 26

sympathetic stimulation of beta receptors causes

Answer 26

vasodilation to increase blood flow to a location

Question 27

alpha adrenergic receptors are located where

Answer 27

all arterioles

Question 28

beta adrenergic receptors are located where

Answer 28

atria and ventricles

Question 29

the endothelial cells of an arteriole can also regulate its blood flow via:

Answer 29

-vasodilators and vasoconstrictors (molecules). this is controled by the flow within the arteriole (ex. if there is increased flow, the endothelial cells sense and release factors to decrease flow...a vasoconstrictor)

Question 30

for muscle arteriole control what is the difference b/w resting muscle and exercising muscle control

Answer 30

at rest, the muscle is under extrinsic control. when exercising, the muscle is under intrinsic control

Question 31

_____ is the primary point exchange b/w the blood and the intersitial fluid

Answer 31

the capillary. diffusion occurs here and intercellular clefts b/w the endothelial cells assist.

Question 32

blood flow in the capillaries is

Answer 32

slow moving. this allows adequate time (and surface area bc the caps are branched!) for diffusion into the interstital fluid

Question 33

define filtration

Answer 33

the movement of fluid/solutes OUT of the blood into the ISF

Question 34

define absorption

Answer 34

movement of fluid/solutes INTO the blood from the ISF

Question 35

crytalloids vs. colloids

Answer 35

crytalloids: low MW penetrating solutes, colloids: non-penetrating plasma proteins

Question 36

what is Pc/capillary hydrostatic pressure

Answer 36

pressure in cap due to blood flow favoring movement OUT of the cap

Question 37

what is Pif/ interstitial hydrostatic pressure

Answer 37

pressure in the ISF favoring movement INTO the cap

Question 38

TTc

Answer 38

osmotic force due to plasma protein [ ] that favors movement of water INTO the cap

Question 39

TTif

Answer 39

osmotic force due to interstitial fluid protein [ ] that favors movement of water OUT of the cap

Question 40

what is net filtration (movmement out of the cap) pressure

Answer 40

an interaction b/w Pc, TTif, Pif, TTc | Pc+TTif-Pif-TTc

Question 41

what causes the increase in venous return to the heart

Answer 41

- sympathetically mediated venoconstriction - skeletal muscle pump - one-way valves