Chapter 9 Flashcards

1
Q

circulatory system works with the

A

pulmonary system to bring O2 to the lungs and the lungs deliver O2 to the tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

purposes of the cardiorespiratory system

A

transport O2 and nutrients to tissues
remove CO2 wastes from tissues
regulate body temp

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

two major adjustments of blood flow during exercise

A

increased cardiac output
redistribution of bloodflow from inactive organs to active muscle (thermoregulation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

pulmonary circuit

A

heart to lungs
on the right side of the heart
pumps DEoxygenated blood to the lungs via the pulmonary artery
returns OXYgenated blood to the left side of the heart via the pulmonary veins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

systemic circuit

A

heart to the rest of the body
left side of the heart
pumps OXYgenated blood to the whole body via the arteries
returns DEoxygenated blood to the right side of the heart via the veins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

plasma

A

liquid portion of the blood
contains ions, proteins, and hormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

RBCs

A

has Hb to carry O2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

white blood cells

A

important in preventing infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

platelets

A

important in blood clotting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how to calculate hematocrit

A

hematocrit= height of RBCs/total height

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

hematocrit

A

what percent of blood is made of packed RBCs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

average hematocrit males and females

A

males = 42%
females = 38%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

blood flow is directly proportional to

A

the pressure difference between two ends of a system (change in pressure)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

blood flow is inversely proportional to

A

resistance (increase resistance, decrease bloodflow)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

blood flow equation

A

blood flow= change in pressure/resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

pressure is proportional to

A

the difference between MAP and right atrial pressure (change in pressure)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

diastole

A

relaxation period
pressure in the ventricles is LOW
filling with blood from the atria
AV valves open when ventricular pressure is LESS THAN atrial pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

systole

A

contraction phase
pressure in ventricles rises
blood is ejected to pulmonary and systemic circulation

aortic and pulmonary semilunar valves open when ventricular pressure is GREATER than aortic pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

at rest what is longer: diastole or systole

A

diastole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what happens to both systole and diastole during exercise

A

get shorter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

appropriate order of events in left ventricle

A

ventricular filling - atrial contraction forces small amount of blood into ventricles
isovolumetric contraction- ventricles contract with no corresponding volume change
ventricular ejection- as pressure increases, blood is ejected into aorta
isovolumetric relaxation- ventricles relax with no corresponding volume change

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

cardiac output

A

the amount of blood pumped by the heart each minute
Q=HR x SV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is stroke volume

A

the amount of blood ejected in each beat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

cardiac output depends on

A

HR
SV
and training state and sex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

typical resting HR for untrained males and females

A

males- 72
females- 75

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

typical resting SV for untrained males and females

A

males- 70
females- 60

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

typical Q for untrained males and females

A

males- 5.00
females- 4.5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

typical max HR for untrained males and females

A

200 for both

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

typical max SV for untrained males and females

A

males- 110
females- 90

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

typical Q at max for males and females

A

males- 22.0
females- 18.0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

parasympathetic regulation of HR

A

via vagus nerve- slows HR by inhibiting SA and AV node

preganglionic neuron releases ACh onto post-ganglionic neuron
post-ganglionic neuron releases ACh onto mAChr
G protein conformational change
G protein inactivates Ca2+ channel, inhibiting it from entering the cell
G protein also opens K+ channel, allowing it to exit the cell. This causes hyperpolarization as the cell becomes more negative making it harder to generate an action potential, slowing HR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

sympathetic regulation of HR

A

via cardiac accelerator nerves- increases HR by stimulating SA, AV, and cardiac tissues

preganglionic neuron releases ACh onto post ganglionic neuron
post-ganglionic neuron releases NE onto B1-ADR
This causes a G protein conformational change which signals a 2nd messenger to open Na+ and Ca2+ channels.
Na+ and Ca2+ enter the cell, depolarizing the cell by making it more positive, making it easier to generate an action potential which increases HR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

what is responsible for the increase in HR at onset of exercise

A

PNS withdrawl

if the function of the vagus nerve is hyperpolarizing the cell making it harder to generate an action potential, withdrawl of this function would actually increase HR and allow sympathetic pathway to take over

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

an increase in temperature does what to HR

A

increases HR to maintain perfusion pressure

if we are devoting blood to other areas of the body, the heart has to work harder to maintain perfusion pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Heart Rate Variability (HRV)

A

variation time between HRs
measured at R-R (peak to peak) interval using ECG tracing

36
Q

wide range in resting HRV=

A

good index of a healthy balance between SNS and PNS

37
Q

low variation in resting HRV =

A

bad
imbalance in autonomic regulation
excellent predictor of CV dysfunction

if we have low variability (same HR at rest) we lost PNS input and only have SNS input which is a sign of too much stress, no longer have vagus nerve input to AV and SA nodes)

38
Q

diseases that promote a decrease in HRV:

A

depression
hypertension
heart disease, including myocardial infarction
physical inactivity

39
Q

what activity results in increased HRV

A

regular bouta of aerobic exercise

40
Q

EDV

A

end diastolic volume
aka preload

volume of blood in ventricles at the end of diastole

41
Q

increased EDV does what to SV

A

increases SV

because volume is increasing

42
Q

frank starling mechanism

A

EDV (preload)
greater EDV results in a more forceful contraction
- if you stretch the heart/ventricles more they get lined into a more optimal position to generate more forceful contraction
dependent on venous return and filling time

43
Q

venous return is increased by

A

venoconstriction via SNS
skeletal muscle pump
respiratory pump

44
Q

skeletal muscle pump

A

rhythmic skeletal muscle contractions force blood in extremities towards the heart
one way valves in veins prevent backflow of blood

exercising= constantly constricting veins= constantly moving blood back to heart = increasing preload

45
Q

respiratory pump

A

changes in thoracic pressure pull blood towards the heart, increasing venous return, increasing preload

46
Q

filling time affected by

A

HR
Body position

47
Q

what body position increases preload

A

supine due to equal distribution of the blood in veins

48
Q

average aortic pressure

A

pressure the ventricles must pump against to eject blood
aka afterload
dependent on MAP

49
Q

stoke volumes relationship to afterload

A

stoke volume is INVERSELY proportional to afterload

increase afterload = decreases SV

50
Q

a decrease in afterload results in

A

an increase in SV, decrease in ESV, and decrease in LVP

51
Q

strength of ventricular contractility (inotropy) enhanced by

A

circulating Epi/NE and direct SNS stimulation of heart via cardiac accelerator nerves

52
Q

less inotropy results in

A

less NE/Epi binding onto target cells (ventricles/cardiac tissues) resulting in a not as forceful contraction

53
Q

more inotropy results in

A

more Epi/NE binding onto B1ADR
more G protein conformational change to 2nd messenger to open channels
makes it easier to generate action potential which depolarizes the cell increasing HR

54
Q

increase inotropy results in

A

decreased ESV and increased SV

55
Q

what is an increase in SV during exercise due to

A

increase EDV (preload)
increased inotropy

56
Q

fick equation

A

VO2= Q x (a-v)O2difference

57
Q

increased O2 delivery accomplished by what during exercise

A

increased Q
redistribution of blood flow from inactive organs to working skeletal muscle

58
Q

up to 40-60% VO2 max due to

A

increased HR
increased SV

59
Q

greater than 40-60% VO2 max due to

A

increased HR only

60
Q

unless an elite athlete, what happens to EDV and SV

A

decreases and plateaus because at high HR, filling time is decreased

61
Q

what body position results in an increased SV

A

supine position due to increase in EDV due to less pooling of blood in the legs

62
Q

what happens to blood flow during exercise

A

increased blood flow to working skeletal muscle

63
Q

at rest, what % of Q goes to muscle

A

15-20%

64
Q

at maximal exercise, what % of Q goes to muscle

A

80-85%

65
Q

what happens to bloodflow to less active organs during exercise

A

decreased bloodflow to liver, kindeys, GI tracts

66
Q

redistribution of blood flow during exercise depends on

A

metabolic rate

67
Q

regulation of muscle blood flow during exercise is primarily mediated by

A

local factors (autoregulation)

intrinsic control of bloodflow by increases in local metabolites (nitric oxide, prostaglandins, ATP, adenosine, and endothelium-derived hyperpolarization factors) all promote vasodilation to increase blood flow to working muscle tissues

68
Q

does the a in (a-v)O2 difference ever change

A

no = it is the amount of O2 found in arteries

69
Q

what is arteriovenous difference?

A

the amount of O2 that is taken up from 100mL blood

70
Q

during exercise what happens to (a-v)O2difference

A

increases due to higher O2 uptake in tissues
used for oxidative ATP production

as you start exercising/muscles activated you are consuming more O2 which means that the partial pressure of O2 at the mitochondria/muscles decreases; this increases the gradient for O2 to move from arteries into the tissues which yields a lower value on venous or returning blood

71
Q

as we consume more O2 in tissues, what happens to venous return

A

decreases
more O2 being pulled into tissues, lower partial pressure of O2 at mitochondria

72
Q

what causes an elevated HR and BP in emotionally charged environments?

A

increases in SNS activity

73
Q

emotional influence on HR and BP

A

can increase HR and BP
does not increase peak HR or BP during exercise

74
Q

transition from rest to exercise: onset of exercise

A

rapid increase in HR, SV, Q
plateau in submaximal (below lactate threshold) exercise

75
Q

HR and Q during graded exercise

A

increases linearly with increasing work rate
reaches plateau at 100% VO2 max

76
Q

BP during graded exercise

A

MAP increases linearly
systolic BP increases all the way to max
Diastolic BP remains fairly constant

77
Q

arm vs leg exercise: which yields a higher HR and BP

A

at the same absolute workload (1L/O2 in arms/legs)
the arms will yield a higher BP and HR because vascular capacity is much smaller in upper body/arms (network/# of blood vessels much smaller, but if you send same amount of blood into a smaller network, you increase pressure)

increased BP = vasoconstriction of large inactive muscle mass
increased HR= higher sympathetic stimulation

78
Q

recovery of HR and BP between bouts depends on

A

fitness level
temp and humidity
duration and intensity of exercise

79
Q

HIIT

A

power output constant but HR is gradually increasing between intervals (don’t have full recovery of HR before the start of the next interval= additive effect and HR slowly starts drifting to max and you potentially start to fatigue out)

this relates to EPOC as it takes a long time for HR and other things to recover at higher intensity exercises

80
Q

during prolonged exercise what happens to Q

A

cardiac output is maintained

81
Q

what happens to SV during prolonged exercise

A

gradual decrease in SV at a constant work rate over time due to dehydration and reduced plasma volume

as time increases, you sweat more and lose fluid, decreasing blood volume, decreasing SV and EDV

82
Q

what happens to HR during prolonged exercise

A

gradual increase in HR (particularly in heat) aka cardiovascular drift

83
Q

cardiovascular drift

A

not able to maintain steady state at high temps or power outputs
can also happen if you start diverting bloodflow to periphery via vasodilation, meaning the heart has to work harder to maintain perfusion pressure

84
Q

how to prevent cardiovascular drift

A

drink water
lower intensity
cooler environment or use cooling measures during exercise

85
Q

transition from exercise to recovery: during recovery

A

decrease in HR, SV, and Q toward resting

86
Q

recovery after exercise depends on

A

duration and intensity of exercise
training state of subject