L18 & 19: Cardiovascular System III & IV

Question 1

major arteries

Answer 1

divide into smaller and smaller arteries, the character of the wall changes, becoming less elastic and more muscular

Question 2

the walls of arterioles

Answer 2

contain several layers of smooth muscles that contract and relax under the influence of chemical signals

Question 3

systemic veins serve as

Answer 3

expandable volume reservoir

Question 4

elastic systemic arteries serve as

Answer 4

pressure reservoir that maintains blood flow during ventricular relaxation

Question 5

capillaries

Answer 5

small, extremely thin, have nucleus, basement membranes, endothelial cells inside

Question 6

veins have ___ than arteries

Answer 6

less muscle tissue

Question 7

veins do not have __

Answer 7

elastic tissue

Question 8

pulse

Answer 8

the pressure increase generated by the left ventricles ejecting blood into the aorta, transmitted through the arteries

Question 9

pulse pressure

Answer 9

pulse pressure = systolic pressure - diastolic pressure

Question 10

venous blood flow

Answer 10

steady and it’s not pulsatile

Question 11

mean arterial pressure

Answer 11

represents driving pressure because arterial pressure is pulsatile

Question 12

MAP formula

Answer 12

MAP = Diastolic pressure + 1/3 pulse pressure

Question 13

hypotension

Answer 13

blood pressure falls too low and blood flow is unable to overcome opposition by gravity

Question 14

hypertension

Answer 14

blood pressure is chronically elevated

Question 15

the elevated pressure in the arteries during diastole is due to

Answer 15

elastic recoil property of arteries

Question 16

arterial blood pressure is measured by

Answer 16

sphygmomanometer and stethoscope

Question 17

when the cuff is inflated above the systolic pressure

Answer 17

arterial blood flow is stopped, no sound

Question 18

when the cuff pressure is below diastolic pressure

Answer 18

the artery is no longer compressed, no sound

Question 19

when the cuff pressure is between systolic and diastolic pressures

Answer 19

turbulent blood flow produces Korotkoff sounds due to compressed artery

Question 20

cardiac output

Answer 20

the amount of blood pumped out of each ventricle in one minute

Question 21

cardiac output formula

Answer 21

CO = Heart rate x Stroke volume

Question 22

total blood volume

Answer 22

around 5 liters

Question 23

normally, cardiac output is

Answer 23

the same for each side of the heart

Question 24

autonomic input to the heart can

Answer 24

raise or lower heart rate and affect cardiac output

Question 25

heart rate is initiated by

Answer 25

autorhythmic cells in the SA node at a rate of 100 bpm in the absence of any nervous or hormonal influence

Question 26

at the resting state

Answer 26

there is more parasympathetic activity to the heart than sympathetic

Question 27

normal resting heart rate

Answer 27

lower, closer to 70 bpm

Question 28

what sympathetic receptors are there in SA node

Answer 28

beta-adrenergic

Question 29

what channels do protein kinases in heart cells trigger to open

Answer 29

F-type Na+ and T-type Ca2+ channels

Question 30

what parasympathetic receptors are there in SA node?

Answer 30

muscarininc cholinergic receptors

Question 31

what channels and how do G-proteins trigger in a parasympathetic pathway?

Answer 31

open K+ and close T-type Ca2+ channels

Question 32

sympathetic NS activity can also

Answer 32

increase the force of contraction and stroke volume

Question 33

when can the sympathetic activity increase the strength of contraction?

Answer 33

at any given end-diastolic ventricular volume

Question 34

Frank-Starling principle

Answer 34

the heart will pump all the blood that returns to it

Question 35

the strength of contraction increases as

Answer 35

the end-diastolic ventricular volume increases

Question 36

mean arterial pressure formula

Answer 36

MAP = Cardiac Output x Total Peripheral Resistance

Question 37

total peripheral resistance

Answer 37

the sum of resistances to flow offered by all the systemic blood vessels

Question 38

the homeostatic regulation of systemic MAP is important because

Answer 38

MAP influences blood flow to all organs in the systemic circuit

Question 39

the primary short-term reflex pathway for control of MAP

Answer 39

baroreceptor reflex

Question 40

sensory receptors of the barareceptor reflex are located

Answer 40

in the walls of carotid arteries (high in the neck) and aorta

Question 41

carotid baroreceptors measure

Answer 41

pressure of blood flowing to the brain

Question 42

aortic baroreceptors measure

Answer 42

pressure of blood flowing to the body

Question 43

___ with changes in blood pressure

Answer 43

baroreceptor firing frequency

Question 44

if increased blood pressure in the arteries stretches the baroreceptor membranes,

Answer 44

the firing rate of the receptor increases

Question 45

if the blood pressure in the arteries falls

Answer 45

the firing rate of the receptors decreases

Question 46

the primary integrating center for the baroreceptor reflex is

Answer 46

medullary cardiovascular control center located in medulla oblongata

Question 47

medullary cardiovascular control center

Answer 47

integrates sensory input and initiates a rapid response

Question 48

in how many minutes are changes in CO and TPR initiated?

Answer 48

in two heartbeats of the stimulus

Question 49

output signals from the cardiovascular control center are carried by

Answer 49

both sympathetic and parasympathetic neurons

Question 50

peripheral resistance is under

Answer 50

tonic sympathetic control

Question 51

increased sympathetic discharge causes

Answer 51

vasoconstriction

Question 52

the heart is regulated by

Answer 52

antagonistic control

Question 53

increased sympathetic activity

Answer 53

increases heart rate at the SA node, shortens conduction time through the AV node, and enhances the force of myocardial contractions

Question 54

increased parasympathetic activity

Answer 54

slows heart rate but has only a small effect on ventricular contraction

Question 55

arterial baroreceptor reflex functions as

Answer 55

short-term regulator of arterial blood pressure

Question 56

if arterial pressure deviates from its normal set point for ___, the arterial baroreceptors ___

Answer 56

more than a few days, adapt to this new pressure

Question 57

arterial baroreceptors cannot

Answer 57

set long-term arterial pressure

Question 58

in individuals who have chronically elevated blood pressure

Answer 58

the arterial baroreceptors continue to oppose minute-to-minute changes, but at a higher set point

Question 59

___ are the single most important long-term determinant of blood pressure

Answer 59

changes in steady-state blood volume

Question 60

if blood volume increases

Answer 60

blood pressure increases

Question 61

an increase in blood volume due to increased fluid ingestion induces

Answer 61

an increase in arterial pressure

Question 62

events that can lead to change in blood volume

Answer 62

dehydration, hemorrhage, ingestion of a large quantity of fluid

Question 63

___ restores blood volume to the original value

Answer 63

increase in excretion of fluid in the urine by the kidneys

Question 64

compensation for decreased blood volume

Answer 64

is more difficult because kidneys cannot restore lost fluid

Question 65

kidneys can

Answer 65

conserve blood volume

Question 66

rapid response to elevated blood pressure

Answer 66

by cardiovascular system: vasodilation and decreased cardiac output

Question 67

slow response to elevated blood pressure

Answer 67

by kidneys: excretion of fluid in urine blood volume