Chapter 34: energetics and physiology of Exercise Flashcards Preview

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Flashcards in Chapter 34: energetics and physiology of Exercise Deck (18):

What is the effect of acute exercise on heart rate, stroke volume, cardiac output and muscle blood flow?

HR increase
SV(volume of blood transported during ventricular systole) increases
CO=HR*SV= volume of blood pumped thru ventricles with each heart beat= about 5L/min at rest. also increases


What muscle regulate muscle blood flow

precapillary sphincter-band of smooth muscle that adjusts blood flow into capillaries mainly in the mesenteric microcirculation


Why does HR increase with acute exercise?

sensory input from proprioreceptors and chemoreceptors


why does SV increase with acute exercise ?

increased venous return (starling mechanism)


Why does muscle blood flow increase with acute exercise?

local control of vasculature, CNS, and hormonal mechanism
decrease in total peripheral resistance


What effect does chronic aerobic exercise have on heart rate, stroke volume, cardiac output and muscle blood flow?

stronger ventricular contractions lead to increase stroke volume and decreased heart rate to maintain a certain CO.
increased perfusion in skeletal muscle and decrease in MAP(mean arterial pressure)= CO *Pr (total resistance which blood must be pumped)


What is the primary fuel used in low intensity exercise?

plasma fatty acids


What is the primary fuel used in moderate intensity exercise?

fatty acids mainly and some glycogen


What is the primary fuel used in high intensity exercise?

mainly glygen storages


What is a type I, slow-twitch skeletal muscle

highly oxidative (more mitochondria)
increased lipid stores
fatigue resistant


What is a type II, fast-twitch skeletal muscle

lower mitochondria and lipid than type 1
fatigue more easily
higher glycogen stores


What is a type 2x, slow-twitch glycolytic skeletal muscle

lowest mitochondria and lipid content of all skeletal muscles
higher glycogen storages
fatigues quickly


Effect of insulin on glucose metabolism

cause GLUT 4 to transport glucose to be stroed as glycogen and FAs are transported into myocytes and stored as TG
increase in ATP and creatine phophate


Effect of exercise on glucose metabolism

1. ATP/CP activiated and used quick
2. Anaerobic glycolysis
low ATP produce lactic acid
3. aerobic metabolism
high ATP yield
produce co2 and h2o
long term


What is VO2 max

-maximum capacity to transport and utilize oxygen during maximal exercise aka aerobic capacity
-gold standard of physical fitness
-measured in lab with increasing exercise until O2 consumption plateaus.
-can be increased by 10%-20% with exercise training


What is lactate threshold? what

point where lactate production is more than clearance during increasing exercise intensity. lactic acid measured in the lab in the blood during increasing exercise intensity.


Effect of lactate threshold on physical fitness. How does chronic exercise training affect lactate threshold.

exercise increases the threshold by increase VO2 so more energy is derived from aerobic processes


Metabolic response to training?

increased mitochondria
increase capillary density in muscles
increased utilization of FAs