lecture 11: cardiovasc reg., functional capacity etc Flashcards

1
Q

beta cells do dilation or constriction

A

dilation

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

alpha receptors do constriction or dilation

A

constriction

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

true or false;Any increase in energy expenditure requires rapid adjustments in blood flow

A

true

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

how does increase in energy expenditure (rapid adjustments in blood flow) impact the entire cardiovascular sysyem

A

takes blood from unimportant tissues (not needed for activity atm) and redistrubutes it to the needed muscle

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

During exercise, local arterioles of active muscles dilate or constrict

A

dilate

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

During exercise, vessels to tissues that can temporarily compromise their blood supply, constrict or dialte

A

consict

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

during exercise what is happes to the vessels of the active adn resting vessels

A

active muscle vessels dilate which inactive constriction

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

give an example of inactive muscle constricting to redistribute blood flow

A

ex: during running, your gut and kidney vessels will constrict and ur sksletel will dilate

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

what are the 2 factors taht contribute to reduced blood flow to non-active tissues:

A

Increased sympathetic nervous system outflow

Local chemicals that directly stimulate vasoconstriction or enhance the effects of other vasoconstrictors

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

true or false: Increased sympathetic nervous system outflow contribute to icnrease blood flow to non active tissues

A

false, DECREASE BLOOD FLOW

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

epinephrin released by sympatethic will active what types of receptors

A

beta and alpha

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

skeletal muscle blood flow couples to what

A

metabolic demand (will not waste sending oxygen if not needed)

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

how does regulation of active myscle flow occur

A

Regulation occurs from the interaction of neural vasoconstriction activity and locally derived vasoactive substances within the endothelium and red blood cells

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

at rest, what is happening at the capilary of sksletal muscle

A

only 1 in 30-40 capilarries remains open

because increase blood supply is not needed at rest

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

what are the 3 functions of the opening of dormant capilaries in exercises

A

Increase total muscle blood flow

Deliver a large blood volume with only a minimal increase in blood flow velocity

Increase the effective surface for gas and nutrient exchange between the blood and muscle fibers

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

true or false: you must increase blood velocity to increase the amounft of blood volume to tisse

A

false, you can just open dormant capilaries

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

vasodilation occurs from local factored related to what

A

related to tissue metabolism that act directly on the smooth muscle bands of small arterioles and precapillary sphincters

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

what are some local factors that act directly on vasodilation

A

Decreased tissue oxygen, local increases in blood flow, temperature, carbon dioxide, acidity, adenosine, magnesium and potassium ions, and nitric oxide production by the endothelial cells lining the blood vessels

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

can the venous side release vasodilatory factors>

A

yes if there needes to be active msucle

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

what is the function of nitric oxide

A

serves as an important signal molecule that dilates blood vessels and decreases vascular resistance

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

is NO a constrictor or dialtor

A

Dialator

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

what are exmaples of things that provoke NO synthesis and release

A

Stimuli from diverse signal chemicals, sheer stress and vessel stretch from increased blood flow through the vessel lumen

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

how is NO released

A

vascular endothelium

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

where are places that the endothelium produces less NO

A

In coronary artery disease (atherosclerosis), diabetes and other disruptions of normal cardiovascular function
(less. vasodilation)

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

what is cardiac output expresses

A

the amount of blood pumped by the heart during a 1-minute period

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

what deos CO reflect

A

functional capacity of the cardiovascular system

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

what is the formualte for cardiac output

A

Cardiac output = Heart rate x Stroke volume

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

what are 3 methods to assess cardiac output

A

Direct Fick
Indicator dilution
CO2 rebreathing

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

what does direct fick method express

A

Expresses the relationships among cardiac output, oxygen consumption, and a-vO2 difference

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

true or false: direct fick is complex?

A

true

Requires complex methodology usually performed in a hospital

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

how can you get CO from direct fick method

A

Measuring oxygen consumption involves open-circuit spirometry methods

Measuring a-vO2 difference involves a sample of arterial blood and from an anatomic “mixing chamber”, then sampling arterial and mixed-venous blood simultaneously

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

explain the indicator diluation method

A

A known quantity of an inert dye whose concentration curve can be measured in blood by light absorption is injected into a large vein

The indicator material remains in the vascular stream and then mixes in the blood as the blood travels to the lungs and returns to the heart before ejection throughout the systemic circuit

A photosensitive device continually assesses arterial blood samples and the area under the dilution–concentration curve reflects the average concentration of indicator material in blood leaving the heart

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

what two methods use open circuit spirometry

A

co2 rebreathing method

direct fick

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

explai nthe co2 rebreathing method

A

The same open-circuit spirometry method for determining O2 consumption in the typical Fick technique determines CO2 production in the rebreathing method

Using a rapid CO2 gas analyzer and making reasonable assumptions about gas exchange provides valid estimates of mixed-venous and arterial CO2 levels
Requires breath-by-breath CO2 analysis

Does not require blood sampling or medical supervision

One limitation is that exercise must be under steady-rate aerobic metabolism, restricting the method’s use during maximal and in the transition from rest to exercise

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

true or false: CO2 required blood sample

A

flase, it does not require sampling or supervision

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

what is one limitation of c02 rebreathing method

A

One limitation is that exercise must be under steady-rate aerobic metabolism, restricting the method’s use during maximal and in the transition from rest to exercise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

true or false: cardiac output varies considerably during rest

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

what are some influencing factors or cardiac output at rest

A

Influencing factors include emotional conditions that alter cortical outflow to the cardioaccelerator nerves and nerves that modulate arterial resistance vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

how can emotional conditions influence CO at rest

A

they alter corticol outflow to the cardioaccelerator nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

what is an avergae CO at rest for men

A

5 L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

what is the average CO at rest for women

A

4L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

men or women have a higher cardiac output at rest

A

MEN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

CO is mostly affected by SV or HR

A

SV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

what are heart rates and SV for resting athetles

A

Heart rates in healthy endurance athletes generally average 50 beats/min at rest while the resting stroke volume averages 100 mL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

what are the 2 factors that explain the large stroke vol and low heart rate of endurance trained atheltes

A

Increased vagal tone and decreased sympathetic drive, both of which slow the heart

Increased blood volume, myocardial contractility, and compliance of the left ventricle, all of which augment the heart’s stroke volume (traiininng ventircular muscles to pump more)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

true or false: endurance athletes dont need to pump as much to get the same CO

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

how are sarcomeres arranged for endurance traininng

A

in series (allow for larger SV)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

how are sarcomeres arranged for resistnace training

A

iin parallel (smaller SV)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

explain how cardiac output moves during exercise

A

Cardiac output increases rapidly during the transition from rest to steady-rate exercise and then gradually until it plateaus when blood flow meets the exercise metabolic requirements

50
Q

when does cardiac output increase rapidly

A

during the transition from rest to steady state

51
Q

when does CO plateau

A

when blood flow meets the exrcise metabilic requirements

52
Q

know the cardiac output curve

A

.

53
Q

The endurance athlete achieves a large maximal cardiac output how

A

solely through a large stroke volume at submaximal exercise

54
Q

what are the 3 factors that increase SV during exercisee

A

1) increased preload
2) decreasd afterload
training adaptations that expand blood vol and ressistnace to blood flow

55
Q

explain how icnreased preload leads to incrase in SV

A

Enhanced cardiac filling in diastole
followed by a more forceful systolic
contraction (frank starling)

56
Q

explain how decraesed afterload/increased contractility increases heart SV

A

Normal ventricular filling with a
subsequent forceful ejection and
emptying during systole

57
Q

true or false: training adaptations have no effect on stroke volume

A

false, Training adaptations that expand
blood volume and reduce resistance
to blood flow in peripheral tissues

58
Q

what factors produce a greater preload during cardiac diastole phase

A

Any factor that increases venous return or slows down the heart will produce greater preload

59
Q

an increase in end disstolic does what to the myocardial fibers

A

stretches them and initiates a powerful ejection stroke during contraction (ejects normal blood and additional)

60
Q

what does frank starling law state

A

Frank-Starling law of the heart states that the force of
contraction of the cardiac muscle remains proportional
to its initial resting length

61
Q

true or false: greater systolic ejection occurs despite increased resistance to blood flow and why

A

true beacsuse of exterice induced elevation of systolic bp

62
Q

if there is an increased BP will there be greater systolic ejection or less

A

greater = more contractility

63
Q

what enhances myocardial contractiole force

A

catacholine relrease in exercise

64
Q

what is the fucntion of catacholine release in exercise

A

Catecholamine release in exercise enhances myocardial contractile force to augment stroke power and facilitate systolic emptying

65
Q

true or false: the ventricles always contain functional residual blood bolume and why

A

true because it is easier to fill if blood is already in and does not allow the ventricles to collapse

66
Q

during exercise there is an incrase in pressure in systemic circulation so what does the heart need to do to compensate and how does it do it>

A

heart must build up a higher diastolic pressure to pump blood against the higher resistance.

iwth more sympathetic innervation and catechline release, the heart will increase pressure and eject more blood despite increase in ressitance

67
Q

what does cardiovascular drift describe

A

Describes the gradual time-dependent downward “drift” in several cardiovascular responses, most notably stroke volume with concomitant heart rate increase, during prolonged steady-rate exercise

68
Q

ADD SLIDES ON CARDIOVASCULAR DRIFT

A

/

69
Q

at rest, the typical cardiac output generally distributes by what locations

A

One fifth flowing to muscle tissue

The digestive tract, liver, spleen, brain, and kidneys receive major portions of the remaining blood
=depends on metabolic needs

70
Q

most of cardiac output divers to where during exercise

A

to active muscles

71
Q

most of the blood diversed to what portions of the muscle during exrceise

A

Most of the blood diverts to oxidative portions of muscle at the expense of those with high glycolytic capacity

72
Q

for trained individuals, when does blood redistrubute begin

A

blood redistribution begins in the anticipatory period just prior to exercise

73
Q

what causes blood to route to active muscles from areas that temporailry tolerate compromised blood flow

A

hormonal vascular regulation and local metabolic condiations

74
Q

hormonal vascular regulation and local metabolic conditions cause blood to do what

A

to route to active muscles away from areas that temporailiy ttolerate compromised blood flow

75
Q

blood redistribution among specfiic tisses occurs primarily during what

A

high intensity exercise

76
Q

true or false: heart and brain tissue can tolerate a compromised blood supply

A

false

77
Q

during redistribution, does blood even get redirected away from heart or brain

A

no , they cannot tolertate reduced blood flow

78
Q

at rest, the myocardium uses what percentage of oxygen in the blood flowingn through coronary circulation

A

75%

79
Q

what does it mean that tthe myocardium uses 75% of the oxygen

A

no backup, therefore if metabolic needs increase, you must increase blood flow sincne you are already taking up oxygen

80
Q

durinng exercise, coronary circulation has what icnrease

A

4-5 fold icnrease

81
Q

does cerebral blood flow ixnrease or decreaes during exercise

A

it icnrease (25-30% compared tp rest)

82
Q

true or false: blood flow to heartt and brain decrease during exercise

A

false, it cannot tolerate that

83
Q

what does an increase in max cardiac output produce

A

produces a proportionate increase in capacity to circulate oxygen and profoundly impacts an individual’s maximal oxygen consumption

84
Q

what is the VO2 formulat

A

VO2 = CO x av VO2 diff

85
Q

A low maximal oxygen consumption corresponds closely with whta

A

with a low maximum cardiac output

86
Q

for every 1 L increase in o2 consumption aboce resting value, you get an icnrease or decrase in blood flow

A

5 to 6 L increase in blood flow

87
Q

true or false: depending on the exercise mode, that will affect the oxugen consumption to blood flow relationship?

A

no

88
Q

what provide distinguishing characteristics for preadolescent and adult endurance athletes

A

High levels of maximal oxygen consumption and cardiac output

89
Q

An almost proportionate increase in maximum cardiac output accompanies what

A

increases in V·O2max with endurance training

90
Q

how can you reach increase levels of oxygen consumpton

A

icnrease CO

91
Q

true or false: Cardiac output and oxygen consumption remain linearly related during graded exercise for boys and girls and men and women

A

true

92
Q

true or false and why Teenage and adult females exercise at any level of submaximal oxygen consumption with a 5-10% larger cardiac output than males

A

true due to a 10% lower hemoglobin concentration

93
Q

do the higher heart rates in children during submaximal exrcise compensate for a smaller decreased volume

A

no

94
Q

since kids have a smaller SV, they compensate with their HR

A

false cannot therefore they have a smaller cardiac output

95
Q

since kids have a smaller SV and therefore a decrase CO what expands to meet the oxygen requirements

A

the a-VO@ difference expands

96
Q

during rest what is the VO2 difference

A

5 ml of oxygen per dl of blood perfusing the tissue capilarry bed

97
Q

during rest, we use alot of oxygen

A

false, we keep 75% of origial oxygen load bound to hemoglobinn

98
Q

where is 75% of the bloods origian oxygen load remai nbound to

A

hemoglobin

99
Q

why is there 75% of oxygen that remain in circulation at rest

A

because it keeps it as a back up incase you need to increase oxygen consumption nwithout icnrease CO

100
Q

During maximum exercise, what does hemoglobin do

A

releases a considerable quantity of its “reserve” oxygen from blood that perfuses active tissues

101
Q

What are the two factors tht increse oxygen consumption durinf exedtckse

A

increased CO

expanded vo2 diff

102
Q

The progressive expansion of the a-vO2 difference results from what

A

a reduced venous oxygen content

103
Q

why dies The capacity of each deciliter of arterial blood to carry oxygen increases during exercise

A

from an increase in hemoconcentration

104
Q

hemoconcentrationn results from what

A

Hemoconcentration results from the progressive movement of fluid from the plasma to the interstitial space with:

  • increased in cap hydrostatic pressure as BP arries
  • metabolic byproducts of exercise metabilise that osmotically draw flioe into tissue spaces from plasma
105
Q

what interacts to increase oxugen extraction in active tissue during exrecise

A

central and peripheral factors

106
Q

what are the central and peripheral factors icnrease oxygen extractionn inn active tissues during exrceise

A

A large portion of the cardiac output is diverted to active tissue

Some tissues temporarily decrease their blood supply to make more oxygen available

Exercise training redirects a greater portion of the central circulation to active muscle

An increase in skeletal muscle microcirculation
An increased capillary-to-fiber ratio
An increase in the size and number of mitochondria
Augmenting aerobic enzyme activity
Local vascular and metabolic improvements within muscle enhance its capacity to produce ATP aerobically

107
Q

explai nthe factors effecting the execsinng aVO2 difference

A

.

108
Q

The highest oxygen consumption during arm exercise averages BLANK lower than leg exercise

A

20 to 30%

109
Q

IS MAXIMAL oxygen soncumption lower in arm por leg

A

leg

110
Q

why is the oxygen consumption for arms lower

A
111
Q

Arm exercise produces BLANK for heart rate and pulmonary ventilation

A

lower maximal values

112
Q

WHY ARE There differences between arm and leg vo2

A

relate to the relatively smaller muscle mass activated in arm exercise

113
Q

there are higher or lower oxygen consumption during arm exercise at all submaximal power outputs

A

higher

114
Q

what are te 2 factors that produce additional oxygen cost at higher intensityies of arm execise

A

Lower mechanical efficiency in upper-body exercise from the additional cost of static muscle actions that do not contribute to external work

Recruitment of additional musculature to stabilize the torso during arm exercise

115
Q

Any level of submaximal oxygen consumption or power output with upper-body exercise provides greater BLANK than lower-body exercise

A

physiologic strain than lower-body exercise

116
Q

submaximal arm exersices produce higher…

A

Heart rates, pulmonary ventilations, perceptions of effort, and blood pressure

117
Q

true or false: submaximal arm exrcised are good for cardiovascular patients

A

no because it increases bp and HR

118
Q

why is there an elevated heart rate response durinng sibmaximal arm exrcises

A

Greater feed-forward stimulation from the brain’s central command to the medullary control center

Increased feedback stimulation to the medulla from peripheral receptors in active tissue

119
Q

true or false: Exercise prescriptions based on running and bicycling do not apply to arm exercise

A

true

120
Q

why can you not predict aerobic capacity for arm exercise based on a test that uses the legs and vice versa

A

becuase low correlations between vo2 max in arm and leg

121
Q

what amplifies the specficicity concept

A

The lack of strong association between the two exercise modes amplifies the specificity concept