Lesson 3 Cardiopulmonary Response to Exercise Flashcards
1
Q
What is cardiac output?
A
- amount of blood ejected from the left ventricle per minute
2
Q
What is the equation of cardiac output?
A
Q = HR x SV
3
Q
What is the avg cardiac output for men and women at rest?
A
5 L/min for men
4L/min for women
4
Q
How much does cardiac output increase during maximal exercise?
A
increases to 35-40 L/min
5
Q
What is stroke volume?
A
- the amount of blood ejected from left ventricle during single contraction
6
Q
What is the stroke volume equation?
A
SV = EDV - ESV
7
Q
What are EDV and ESV?
A
ESV: amount of blood ejected during singular contraction of left ventricle
EDV: amount of blood left in left ventricle after ventricular contraction
8
Q
What is systolic blood pressure?
A
- pressure in circulatory system against the walls of the blood vessels during ventricular systole
9
Q
What is diastolic blood pressure?
A
- pressure in circulatory system during ventricular diastole
10
Q
What is mean arterial pressure?
A
avg perfusion pressure delivered to organs
11
Q
How much must mean arterial pressure be maintained to sustain adequate flow to tissues?
A
60 mmHg
12
Q
What is the normal range of mean arterial pressure?
A
70-110 mmHg
13
Q
What is rate pressure product and what can it be used for?
A
index of myocardial oxygen consumption
can be used to prescribe safe exercise zones in people with high blood pressure
14
Q
What is the equation for rate pressure product?
A
RPP = HR x Systolic blood pressure
15
Q
What is a-vO2 difference?
A
- difference between oxygen content of arterial and venous blood
16
Q
What happens to a-vO2 difference during exercise? Why?
A
- greater difference as tissue needs to take in much more oxygen during exercise
17
Q
How does cardiac output change during exercise?
A
increases significantly to meet oxygen demand due to increase in HR and SV
18
Q
What does the sympathetic nervous system do in terms of HR?
A
- increases HR and force of contraction
19
Q
What does the parasympathetic nervous system do in terms of HR?
A
- signals vagus nerve to decrease the HR
20
Q
What are the receptors that help in feedback during exercise?
A
mechanoreceptors, chemoreceptors, and baroreceptors
21
Q
What is the influence of central input of the medulla on exercise?
A
- peripheral input and central motor command integrated in this location
the thought of activity can increase HR alone
22
Q
What triggers the initial increase in HR during exercise?
A
- reduced PNS activity
- activation of cerebral cortex in anticipation of exercise
- activation of mechanoreceptors
23
Q
How is HR fine tuned during exercise?
A
- SNS activation
- input from chemoreceptors
- input from baroreceptors
24
Q
What is heart rate variability?
A
variation in time from one heartbeat to the next
25
What are the implications on health when it comes to increased or decreased heart rate variability?
increased: healthy and norma
decreased: can predict cardiac health deficits and inadequate recovery from exercise
26
What are the two main ways stroke volume can increase?
1. increased EDV from increased filling
2. decreased ESV with greater force of contraction
27
When is stroke volume at its highest?
EDV is high and ESV is low
28
What are the two ways EDV is maintained or increased during exercise?
central venous pressure through muscle pump and systemic venous constriction (less blood to heart)
respiratory pump
29
How is ESV increased during exercise?
- frank-starling reflex: more stretch more contraction
30
How does exercise affect diastolic blood pressure?
exercise training reduces DBP by reducing the resistance against which the ventricular contraction pumps blood
31
When do HR and SV increase with exercise?
immediately increase
32
How does HR increase with exercise intensity?
increase linearly
33
When does SV stop increasing linearly with exercise?
40% VO2max, starts to increase slower
34
What does exercise training do to EDV?
- increase in blood volume
- increase filling during diastole
- increased ventricular stretch
35
How does exercise training affect ESV?
- increased force of contraction
- less resistance in vascular system
36
Where does blood mainly flow during exercise?
- active muscle and the heart
- maintains flow to brain
- decreases in inactive muscle and organs
37
What are the factors that influence and regulate the distribution of blood flow during exercise?
- vaso/venoconstriction
- vascular tone
- local vasodilation
38
What is the main compound that causes vasodilation?
nitric oxide
39
What happens during prolonged exercise?
- heat increases and the body responds by vasodilation to regulate temperature
40
What happens to SBP and DBP during endurance exercise?
- SBP increases (HR and SV)
- DBP decreases slightly (peripheral resistance)
41
What happens to SBP and DBP during resistance exercise?
both increase in proportion to force generated and mass of muscle activated
42
What is the pressure response?
- during muscle contraction, vessels become compressed, causing muscle to be temporarily ischemic
- reflexive increase in blood pressure
43
What happens to the baroreceptor reflex during exercise?
set point is raised and MAP is maintained
44
What happens during the valsalva maneuver?
- activation of expiratory muscles against closed glottis to stabilize abdominal and thoracic cavities
- veins become compressed due to intrathoracic pressure which can decrease blood flow to heart and brain, causing dizziness
45
Between arm and leg exercises, where does blood pressure increase the most?
arm exercises
46
What is ventilation?
the process of moving gas into and out of the lungs
47
What is respiration?
exchange of gasses
48
What are pulmonary and cellular respiration?
pulmonary: exchange of gases in the lungs
cellular: exchange of gases at muscle and other organs
49
What is tidal volume?
- amount of air inhaled and exhaled with each breath
50
What is inspiratory reserve volume?
- amount of air that can be forcefully inhaled above tidal volume
51
What is inspiratory capacity?
the max amount of air that can be inspired after normal expiration
52
What is the equation of inspiratory capacity?
IC = tidal volume + inspiratory reserve volume
53
What is expiratory reserve volume?
amount of air that can be forcefully exhaled after normal tidal expiration
54
What is residual volume?
the amount of air remaining in the lungs after forced expiration
55
What is functional residual capacity?
the amount of air remaining in the lungs at the end of normal tidal expiration
56
What is the equation for functional residual capacity?
FRC = end reserve volume + residual volume
57
What is vital capacity?
max amount of gas that can be exhaled after a max inhalation
58
What is the equation for vital capacity?
VC = inspiratory reserve volume + tidal volume + expiratory reserve volume
59
What is maximal voluntary ventilation?
- rapid breathing for 15 seconds
60
What is Dalton's law (gas partial pressure)?
- the total pressure of a mixture of gases is the sum of partial pressure of each gas
61
How much of air is oxygen?
20.93%
62
What is the difference between paO2 and PAO2?
paO2 = arterial
PAO2 = alveoli
63
How does altitude affect gases?
- decreased pressure decreases partial pressure
- will decrease the rate of diffusion
64
What is the partial pressure comparison between O2 and CO2 in the alveoli?
O2 high, CO2 low
65
What is the ventilation perfusion ratio?
rate of perfusion in pulmonary capillaries (Qc) must match ventilation (Va) in order for optimal gas exchange
Va/Qc: ratio of alveolar ventilation to alveolar blood flow, optimal when = 1
66
What happens to the ventilation perfusion ratio with exercise?
moves closer to 1 because even distribution of blood flow
exceeds 1 at high intensity
67
What is 99% of oxygen bound to in the blood?
hemoglobin
68
How is the O2-hemoglobin dissociation curve altered by temp, pH, and 2,3 DPG?
temp: increase shifts curve to right, weaker bond, more O2 release at muscle
pH: decrease shift curve to right, weaker bond, more )2 release
2.3 DPG: increase shifts curve to right
69
What happens during the buffering (transportation) of CO2?
- 10% remains in blood
- 20% binds to hemoglobin
- 70% converted to bicarbonate by red blood cells
70
What is the optimal pH of blood?
7.4
71
If there is too much CO2 in the blood, how does the blood become acidic?
when CO2 combines with water it creates carbonic acid, in reaction the release of hydrogen ions makes blood acidic
72
What does exercise do to CO2 production?
increases CO2 production, increasing hydrogen ions and lowering plasma pH
73
What is the body's response to high CO2 levels in the blood?
increased ventilation to "blow off" CO2
74
What is ventilatory threshold?
point at which ventilation increases disproportionally to metabolic demand
