Cardiovascular Response to Exercise Flashcards
How fast does the SA node make the heart beat alone
100 bpm
What mechanoreceptors send signals to the ventrolateral medulla (3)
- Arotic and carotid
- Cardiac
- Skeletal muscle
What metaboreceptors send signals to the ventrolateral medulla (1)
- Skeletal muscle
What else sends information to the ventrolateral medulla (1)
- Higher brain centers
What is another name for the ventrolateral medulla
Cardiovascular center
What does the ventrolateral medulla control
HR
What does HR typically increase with in a linear fashion
Work rate and oxygen uptake
What does the magnitude of increase for HR depend on (8)
- Age
- Body position
- Fitness level
- Type of activity
- Presence of disease
- Medications
- Blood volume
- Environmental factors
How do you calculate your max HR
220-age (+/- 10 bpm)
What happens if workload or oxygen uptake increases
HR increase
At submaximal work why can we use HR to estimate VO2 max
Because oxygen uptake and HR have a direct relationship
What do beta blockers do
Reduce stress on cardiovascular system by suppressing the sympathetic nervous system
What is stroke volume (SV)
Volume of blood ejected from the heart per beat
How do you calculate SV
SV=EDV-ESV
What is the normal range of SV
60-100ml/beat
What is the maximum SV range
100-120ml/beat
What is the contraction phase
Systole
What is the resting/filling phase
Diastole
What are the 3 ways to increase SV during exercise
- Increase filling
- Increase contraction
- Training adaptions that increase BV and reduce resistance to flow
What is preload of the heart
Amount of blood in the ventricle before filling
What things increase preload of the heart (2)
- Increased venous return
2. Slow heart rate
Frank-Starling law of the heart states what
The force of contraction of cardiac muscle remains proportional to its initial resting length
What does SV increase curvinlinearly with
Work rate
Where does SV reach it’s maximum
About 50% of aerobic capacity
What can happen to SV at higher intensities
Decrease
How can SV decrease at higher intensities
Because HR is so high that the ventricles can completely fill
What is Q
Cardiac output
What is cardiac output
The amount of blood pumped by the heart during a 1 minute period
What does cardiac output reflect
The functional capacity of the cardiovascular system
How do you solve for cardiac output
Q=HR*SV
What is the cardiac output for men and women at rest
Men: 5L
Women: 4L
What is the average HR for men and women
Men: 70bpm
Women: 70bpm
What is the average SV for men and women
Men: 71.4ml
Women: 50-60ml
What portion of the cardiac output goes to the muscle tissues at rest
About 1/5
What does Q increase linearily with
Work rate
At exercise intensities up to 50% VO2 max what are increases in cardiac output do to
Increases in HR and SV