McCumbee - Exercise Flashcards
Pulmonary response to exercise
Increased ventilation
Improved V/Q matching
Cardiovascular response to exercise
Increase CO
Redistribute blood flow
How much O2 a person takes up and delivers to the tissue per minute
VO2
Highest rate of O2 consumption that can be achieved during max exercise
VO2 max
_____ in O2 consumption w/ increasing exercise intensity is the primary criterion that indicates VO2max has been reached
A plateau
What has the greatest impact on limiting VO2max in a normal healthy person?
Cardiovascular function
Up to ____% of variance observed in VO2 max is due to genetics
25-50%
Extensive training can increase VO2max by ____
15-20%
At 2/3 of the way through maximum exercise effort, there is a disproportionate increase in minute ventilation compared to exercise intensity
Ventilatory threshold
At max exercise, the RR is about 40-50 and the tidal volume is about ____ of a person’s vital capacity
60%
In exercise, arterial pH remains constant until _____
Ventilatory threshold is met and Ve cannot keep up with metabolic acidosis
Stroke volume’s response to exercise:
At low to moderate workloads, increases w/ level of exertion, but then plateaus as the level of exercise becomes more intense
What maintains the stroke volume during exercise
Mechanisms that aid in venous return:
Muscle pump
Larger and more freq inspirations
Venoconstriction due to sympathetics stimulation of alpha adrenergic receptors in veins
Arterial vasodilation in the exercising muscles
Sympathetic stim increases ventricular inotropy
Increased lusitropy
Atrial inotropy enhances atrial kick
Stroke volume can increase about _____ during exercise
50%
Systemic vascular resistance ______ as work intensity increases because of vasodilation
Decreases
Blood pressure and heart rate are _____ related
Inversely
During exercise, the arterial baroreceptor reflex is operating at a __________. Requiring a higher rise in blood pressure to cause a compensatory decrease in heart rate
Higher set point
The net effect of widespread sympathetic stimulation and local vasodilation from metabolites is?
Shunting blood flow from inactive tissues to actively contracting muscles
Two events that occur to increase blood flow to actively contracting skeletal muscles during exercise
Increase CO
Redistribution of blood to actively exercising muscles and away from other organs (splanchnic)
During periods of intense exercise, blood flow to contracting muscle can account for more than ____ % of cardiac output
80
More blood in contracting muscles is diverted to regions of muscle containing ______ fibers at the expense of regions with ______ fibers
Oxidative
Glycolytic
Aerobic training -___ O2 delivery by _______ maximum cardiac output
Increases
Increases
Increased O2 extraction in trained athletes is due to ?
Increased capillary proliferation
Increased capillary density which causes diffusion distance of O2 to drop.
Increased size and number of mitochondria in skeletal muscle fibers
