Workbook 1 Flashcards
(156 cards)
An individual bout of exercise; the bodies immediate response to an exercise bout
acute exercise
What is the primary function of the cardiovascular system?
ensure adequate blood flow throughout circulation to meet the metabolic demands of the tissues
which nervous system controls HR ?
sympathetic
two formulas for determining HR max? Which is most accurate?
- 220 - age
2. 208 x ( .7 x age in years ) * more accurate
Steady state HR
- 2-3 minutes to reach at constant intensity
- the demands of the active tissues can be adequately met by the cardiovascular system
systolic blood pressure _____ during acute exercise. What about diastolic?
increases
- diastolic does not change significantly during exercise (may slightly decrease)
Receptors are responsible for what?
What are the 3 receptors?
- modifying blood pressure
1. baroreceptors
2. chemoreceptors
3. mechanoreceptors
What do each of the 3 receptors do?
- Baro: excited by stretch of vessel, alert brain
- Mechano: golgi tendon, stretch receptors
- Chemo: monitor O2 levels; chem. of blood
What is stroke volume?
Volume of blood pumped out of LEFT ventricle per contraction
SV = ___ - ____ ?
EDV - ESV (ml)
what is the major determinate of cardiorespiratory endurance capacity (VO2max) ?
stroke volume
4 factors that determine stroke volume
- volume of venous blood returned to heart [preload]
- ventricular dispensability
- ventricular contractility
- aortic or pulmonary artery pressure [afterload]
Stroke volume increases proportional to ___ ____
work rate (plateaus ~40-60% of VO2max)
End diastolic volume (EDV) is..
amount of blood before contraction
End systolic volume (ESV) is..
amount of blood left after contraction
epinephrine increase _____ force
contraction
why is stroke volume influenced by body position?
venous return to the heart; horizontal position has higher stroke volume because of gravity
stroke volume increases with acute exercise for what 3 reasons
- frank-starling mechanism
- sympathetic stimulation
- decreased peripheral resistance due to increased vasodilation to active muscles
what is the frank-starling mechanism?
- Increased volume of blood enters the ventricle (EDV)
- Ventricle stretches and
- Contracts with more force
what is cardiac output?
total volume of blood pumped by the LEFT ventricle per minute
Q (cardiac output) = __ x __
HR x SV (L/min)
Average resting Q ?
5L/min
total blood volume of typical adult is ~5L
Q increases with exercise intensity up to….
~ 20-40 L/min
8x more than resting value
3 functions of blood flow that are important for exercise
- transport oxygen
- temperature regulation
- acid-base balance