Chapter 34: energetics and physiology of Exercise Flashcards Preview

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Flashcards in Chapter 34: energetics and physiology of Exercise Deck (18)
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1
Q

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

A

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

2
Q

What muscle regulate muscle blood flow

A

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

3
Q

Why does HR increase with acute exercise?

A

sensory input from proprioreceptors and chemoreceptors

4
Q

why does SV increase with acute exercise ?

A

increased venous return (starling mechanism)

5
Q

Why does muscle blood flow increase with acute exercise?

A

local control of vasculature, CNS, and hormonal mechanism

decrease in total peripheral resistance

6
Q

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

A

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)

7
Q

What is the primary fuel used in low intensity exercise?

A

plasma fatty acids

8
Q

What is the primary fuel used in moderate intensity exercise?

A

fatty acids mainly and some glycogen

9
Q

What is the primary fuel used in high intensity exercise?

A

mainly glygen storages

10
Q

What is a type I, slow-twitch skeletal muscle

A

highly oxidative (more mitochondria)
increased lipid stores
fatigue resistant

11
Q

What is a type II, fast-twitch skeletal muscle

A

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

12
Q

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

A

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

13
Q

Effect of insulin on glucose metabolism

A

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

14
Q

Effect of exercise on glucose metabolism

A
  1. ATP/CP activiated and used quick
  2. Anaerobic glycolysis
    short
    low ATP produce lactic acid
  3. aerobic metabolism
    high ATP yield
    produce co2 and h2o
    long term
15
Q

What is VO2 max

A
  • 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
16
Q

What is lactate threshold? what

A

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.

17
Q

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

A

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

18
Q

Metabolic response to training?

A

increased mitochondria
increase capillary density in muscles
increased utilization of FAs