Chapter 4 - Acute Responses to Excercise Flashcards
What is an average resting heart rate?
70 bpm
What is a 20 year olds maximum heart rate?
200 bpm
What is stroke volume?
The volume of blood pumped out by the left ventricle with each beat
What is the stroke volume at rest and during maximal exercise?
Rest; 60-80ml
Max: 120-130ml
What is Cardiac ouput and what is it’s equation?
Volume of blood pumped out of the left ventricle per minute.
Equation: Q=SV*HR
What is cardiac outpt at rest and during maximal exercise?
Rest: 4-6 L/min
Maximal Exercise: 22-24L/min
What is venous return and through which three main mechanisms does it do so?
The amount of blood returning to the heart through the veins
Mechanisms: muscle pump, respiratory pump, venoconstriction
What is Artirio-venous oxygen difference (A-VO2 diff), and what arterial and venous O2 levels can you expect during rest? What is the A-Vo2 difference and what % of it is used?
Rest arterial O2 concentration: 20 ml/100ml Rest venous O2 concentration: 12-15 ml/100ml Diff: 5ml/100ml
% of used O2: ~25%
What % O2 is used in the working muscles during maximal excercise?
Up to 100% of the 20ml/100ml of O2 is extracted by the working muscles during max intensity exercise
What is a persons respiratory rate during rest or moderate and maximal exercise?
Rest:12-15
Moderate exercise: 30-35
Maximum exercise: 48-60 (3-4*rest)
What is a persons tidal volume (TV) and how does it change during rest and moderate and maximum intensity exercise?
Volume of air breathed in and out each breath
Rest: 0.5L
Moderate exercise: 2.5L
Maximum exercise; 4.0L
What is minute ventilation? How does it change during rest and moderate and maximal exercise?
Volume of air breathed in each minute
Rest:6L/min
Moderate exercise: 75L/min
Maximal: 200L/min
What is diffusion and the two sites it occur at, and how it occurs at each site?
The movement of molecules from areas of high concentration to areas of low concentration.
Alveolar-capillary
Increased O2 intake increases surface area of alveoli and increased Co2 levels are present in the blood due to exercise.
muscle tissue - capillary
muscles require more oxygen and capillaries surface area increases due to increased blood flow to the working muscles.
What is Vo2 and what is it rest?
The amount of oxygen taken up and used each minute.
Rest: .25L/min
How is blood redistributed during exercise and how much does the blood supply change for muscles during rest and exercise.
Vasodilation and vasoconstriction directs blood away from many organs toward the working muscles.
Muscle rest: 15-20%
Muscle Exercise: 80-85%
What is the blood pressure (S/D) during rest and maximal excertion
Rest: 120/80
Max: 200/82
Difference between Venoconstriction and vasoconstriction
Venoconstriction is the narrowing of the veins while vasoconstriction is the narrowing of the vessels (veins and arteries) in general.
Difference between stylostic and dialostic blood pressure?
Stylostic: Pressure in the arteries following a hearts contraction
Dialostic: Pressure in the arteries during the relaxation phase of a hearts cycle
How is stylostic and dialostic blood pressure effected by resistance training?
Stylostic: Increase
Dialostic: Increase
Which increases blood pressure more? Aerobic or resistance training?
Resistance training
How does plasma volume change during exercise?
decreases 10% in first 5 minutes of exercise and decreases more as person becomes dehydrated.
What % of blood is ejected from the left ventricle at rest?
40-50%
How many minutes until the stroke volume decreases during sub-maximal exercise?
30 minutes
What is the two ways which muscles increase force of output?
- Recruitment of motor units
- Increase rate of firing of motor units
What Is the ventilators threshold and What % of max HR does it occur?
- When ventilation increases at non linear rate
- occurs 65-75% of max HR
Relationship between HR, SV and Q and maximal and sub maximal intensities:
HR increases linearly until max HR is reached. However SV plateaus at sub maximal intensities and therefore any increase in
Name 4 acute respiratory responses to exercise.
Minute ventilation
Tidal Volume
Respiratory rate
Diffusion
Name 9 cardiovascular responses to exercise?
Vo2 Heart Rate Blood flow redistribution
A-Vo2 Diff Stroke Volume
Blood Volume Cardiac Output
Blood Pressure Venous Return
Name 6 Acute Muscular responses to exercise
Core Body Temperature Redistribution of blood flow
Motor Unit Recruitment Decreased energy substrate levels
Enzyme activity
Lactate Production
What muscles contract during inspiration.
External?? Intercostals
Diaphragm
List structures oxygen passes through to reach the red blood cells.
Alveoli - alveoli membrane - interstitial fluid - capillary membrane - plasma - red blood cells
State the all or nothing principle.
Until a certain threshold is reached no muscle fibres in a motor until will contract, but once this threshold is reached all muscle fibres in the motor unit will contract maximally.
