Cardiovascular Response to Exercise Flashcards
(92 cards)
1
Q
How fast does the SA node make the heart beat alone
A
100 bpm
2
Q
What mechanoreceptors send signals to the ventrolateral medulla (3)
A
- Arotic and carotid
- Cardiac
- Skeletal muscle
3
Q
What metaboreceptors send signals to the ventrolateral medulla (1)
A
- Skeletal muscle
4
Q
What else sends information to the ventrolateral medulla (1)
A
- Higher brain centers
5
Q
What is another name for the ventrolateral medulla
A
Cardiovascular center
6
Q
What does the ventrolateral medulla control
A
HR
7
Q
What does HR typically increase with in a linear fashion
A
Work rate and oxygen uptake
8
Q
What does the magnitude of increase for HR depend on (8)
A
- Age
- Body position
- Fitness level
- Type of activity
- Presence of disease
- Medications
- Blood volume
- Environmental factors
9
Q
How do you calculate your max HR
A
220-age (+/- 10 bpm)
10
Q
What happens if workload or oxygen uptake increases
A
HR increase
11
Q
At submaximal work why can we use HR to estimate VO2 max
A
Because oxygen uptake and HR have a direct relationship
12
Q
What do beta blockers do
A
Reduce stress on cardiovascular system by suppressing the sympathetic nervous system
13
Q
What is stroke volume (SV)
A
Volume of blood ejected from the heart per beat
14
Q
How do you calculate SV
A
SV=EDV-ESV
15
Q
What is the normal range of SV
A
60-100ml/beat
16
Q
What is the maximum SV range
A
100-120ml/beat
17
Q
What is the contraction phase
A
Systole
18
Q
What is the resting/filling phase
A
Diastole
19
Q
What are the 3 ways to increase SV during exercise
A
- Increase filling
- Increase contraction
- Training adaptions that increase BV and reduce resistance to flow
20
Q
What is preload of the heart
A
Amount of blood in the ventricle before filling
21
Q
What things increase preload of the heart (2)
A
- Increased venous return
2. Slow heart rate
22
Q
Frank-Starling law of the heart states what
A
The force of contraction of cardiac muscle remains proportional to its initial resting length
23
Q
What does SV increase curvinlinearly with
A
Work rate
24
Q
Where does SV reach it’s maximum
A
About 50% of aerobic capacity
25
What can happen to SV at higher intensities
Decrease
26
How can SV decrease at higher intensities
Because HR is so high that the ventricles can completely fill
27
What is Q
Cardiac output
28
What is cardiac output
The amount of blood pumped by the heart during a 1 minute period
29
What does cardiac output reflect
The functional capacity of the cardiovascular system
30
How do you solve for cardiac output
Q=HR*SV
31
What is the cardiac output for men and women at rest
Men: 5L
Women: 4L
32
What is the average HR for men and women
Men: 70bpm
Women: 70bpm
33
What is the average SV for men and women
Men: 71.4ml
Women: 50-60ml
34
What portion of the cardiac output goes to the muscle tissues at rest
About 1/5
35
What does Q increase linearily with
Work rate
36
At exercise intensities up to 50% VO2 max what are increases in cardiac output do to
Increases in HR and SV
37
At exercise intensities above 50% VO2 max what are increases in cardiac output do to
Solely HR
38
What is 50% VO2 max equivalent to
Moderate exercise
39
During exercise what causes blood to route to the active muscles (2)
1. Hormonal vascular regulation
| 2. Local metabolic conditions
40
At rest how much of the oxygen in the blood flowing through the coronary circulation does the myocardium use
About 75%
41
During exercise how much does the myocardial blood flow increase
Four to fivefold
42
How much does cerebral blood flow increase during exercise
About 25-30%
43
What does a low maximal oxygen consumption correlate with
A low maximum cardiac output
44
How much extra blood flow accompanies a 1L increase in oxygen consumption
5-6L
45
Increase in maximum cardiac output accompanies increases in what during endurance training
VO2 max
46
What happens if we pump more blood through the system
We have a greater capacity to carry oxygen increasing aerobic exercise
47
Changes in cardiac output dictate changes in what
VO2 max
48
As exercise intensity increases what happens to systolic BP
It increase
49
What does MET mean
Metabolic equivalent
50
What is maximal systolic BP
190-220 mmHg
51
What should systolic BP not exceed
250 mmHg
52
What should diastolic BP not exceed
115 mmHg
53
What is the arterial blood oxygen content at rest
20 mL/dL
54
Does arterial blood oxygen stay the same throughout exercise or change
Stays relatively the same
55
What is the venous oxygen content at rest
12-15 mL/dL
56
What is the venous oxygen content during exercise
2-4 mL/dL
57
What is the a-v O2 difference
The difference between arterial oxygen and venous oxygen
58
What does the difference between arterial oxygen and venous oxygen equal
The amount of oxygen that was off loaded at the tissue
59
True or False:
| You never offload all of the oxygen
True
60
True or False:
| You always reach full arterial O2 capacity
False
61
How is a-vO2 difference increased with exercise (3)
1. Cardiac output is diverted to the active tissue
2. Some tissues temporarily decrease their blood supply
3. Central circulation is redirected to active muscles
62
What are other factors that affect a-vO2 difference during exercise (5)
1. Increase in skeletal muscle microcirculation
2. Increased capillary to fiber ratio
3. Increase in the size and number of mitochondria
4. Aerobic enzyme activity
5. Local vascular and metabolic improvements
63
What is the gradual time-dependent downward "drift" in several cardiovascular responses
Cardiovascular drift
64
What is an example of cardiovascular drift
SV with concomitant HR increase during steady rate exercise
65
How long does the sub maximal exercise have to be to see an increase in HR
30+ minutes
66
Why does HR increase with exercise
You lose plasma volume, which decreases blood volume, and you make up for the lose by increase in HR
67
What happens to HR and BP during resistance training which includes eccentric and concentric phase
They increase
68
What are the peak values for BP and HR for a two legged leg press at 95% 1 rep max with the valsalva manuever
BP: 320/250 mmHg
HR: 170 bpm
69
Does SV increase during concentric or eccentric phase
Concentric phase: Slightly
| Eccentric phase: Increases significantly
70
Why does cardiac output increase
SV
71
What is MVC
Maximum voluntary contraction
72
What is SBP
Systolic blood pressure
73
What is DBP
Diastolic blood pressure
74
What does isometric contractions at 20% of MVC increase
SBP, DBP, and HR
75
Above 20% MVC what happens to HR
It increases in relation to tension exerted
76
What happens to SBP above 20% MVC
Abruptly increases
77
What happens to SV at 50% MVC
Increases slightly
78
What happens to cardiac output during isometric contractions
Moderately increases
79
What is the highest oxygen consumption during arm exercise
20-30% lower than leg exercise
80
True or False:
| Arm exercises produce lower maximal values for heart rate and pulmonary ventilation
True
81
Why is the highest oxygen consumption lower for the arms
Smaller muscle mass activated in arm exercise
82
True or False:
| There is higher oxygen consumption during arm exercise at all submaximal power outputes
True
83
What are some factors that produce additional oxygen cost at higher intensity exercises (2)
1. Lower mechanical efficiency in the upper body exercise
| 2. Recruitment of musculature to stabilize torso
84
What is RPE
Rating of perceived exertion
85
What are the 2 factors that affect RPE
1. Insufficient energy use
| 2. Smaller muscle size
86
How do arm exercise compare to leg exercise relative to work load (3)
1. Higher HR
2. Higher O2 consumption
3. Higher rate of perceived exertion
87
What type of relationship do oxygen and power output have
Direct relationship
88
What is strained more during any level of oxygen consumption or work load lower body or upper body
Upper body
89
Submaximal arm exercises produce higher what (4)
1. HR
2. Pulmonary ventilations
3. Perception of effort
4. BP
90
What does the elevated HR during submaximal arm exercises result from (2)
1. Greater feed forward stimulation
| 2. Increased feedback stimulation
91
How long does it take for changes in cardiovascular function to occur
8-12 weeks
92
What are the factors that affect changes in cardiovascular function (8)
1. Increased plasma volume
2. Decreased submaximal exercise HR
3. Increased SV during rest and exercise
4. Increased maximal CO
5. Increased oxygen extraction
6. Increased coronary blood flow and capillary exchange capacity
7. Decreased BP during rest and submaximal exercise
8. Improvements in blood flow distribution
