Chapter 6 - Acute physiological responses to exercise Flashcards
Cardiovascular system
Q = HR x SV
- Increased heart rate
- Increased stroke volume
- Increased cardiac output
- Increased blood pressure
- Redistributed blood flow to working muscles
- Increased arteriovenous oxygen difference
Increased stroke volume
Is the amount of blood elected from the left ventricle per beat
Increased cardiac output
Is the amount of blood ejected from the left ventricle per minute
Increased blood pressure
Is the pressure exerted by the blood against the arterial walls as it is forced through the circulatory system by the action of the heart
- Systolic
- Diastolic
Systolic blood pressure
Is the pressure recorded as blood is ejected during the contraction phase of the heartbeat
Diastolic blood pressure
Is the value recorded during relaxation of the heart
Redistribution of blood flow to working muscles
- At rest 15–20 per cent of total blood flow is directed to working muscles
- During exercise 80–90 per cent of total blood flow is directed to working muscles
Increased a-VO2 difference
Is a measure of the difference in the concentration of oxygen in the arterial blood and the concentration of oxygen in the venous blood
Respiratory system
V = TV x RF
- Increased respiratory frequency (breathing rate)
- Increased tidal volume
- Increased ventilation
- Increased oxygen uptake
- Increased pulmonary diffusion
Increased respiratory frequency (breathing rate)
Is the number of breaths taken per minute
Increased tidal volume
Is the amount of air breathed in and out in one breath
Increased ventilation
Is the amount of air inspired or expired per minute by the lungs
Increased pulmonary diffusion
The process oxygen is taken from the blood, and carbon dioxide is diffused from the blood to the lungs
Increased oxygen uptake
Is the amount of oxygen transported to and taken to the body for energy production
VO2 max
Is the maximum amount of oxygen per minute that can be transported to, taken up by and used by the body for energy production
Oxygen deficit
Is the state in which there is a shortage between oxygen supply and demand, and the needed to meet energy requirements of the activity
Factors affecting maximum oxygen uptake
- Body size
- Gender
- Age
- Genetics
- Fitness levels
EPOC
Is the amount of oxygen consumed during the recovery period after the completion of an exercise
Muscular system
- Increased motor unit and muscle fibre recruitment
- Increased blood flow in the muscles
- Increased muscle temperature
- Increased muscle enzyme activity
- Increased oxygen extraction and utilisation
- Decreased muscle substrate levels
Increased motor unit and muscle fibre recruitment
- When exercise begins, an increase in motor unit recruitment must take place so that more muscle fibres are activated to contract
- The greater the force or effort required = the greater the number of motor units recruited and the greater the number of muscle fibres activated
Increased blood flow in the muscles
Extra demand of the muscles for oxygen during exercise leads to vasodilation of the capillaries and redistribution of blood flow, from the internal organs to the working skeletal muscles
Increased muscle temperature
Heat generated as a by-product of the increased production of ATP during exercise, results in an increase in muscle temperature
Increased muscle enzyme activity
- Increases to produce the increased amounts of ATP required by the muscles
- Enzymes are involved in all of the chemical processes that produce energy via the three energy pathways
Increased oxygen extraction and utilisation
Muscle cells extract and use more oxygen during exercise
Decreased muscle substrate levels
- All 3 systems begin to deplete during exercise because they are sources of fuel for the production of ATP
- The depletion of these energy stores contributes to the fatigue experienced during exercise and physical activity
