34. Cardiorespiratory Adjustments in Exercise Flashcards
1
Q
Why is venous return increased in exercise?
A
Muscle blood flow
Venoconstriction
Muscle pump
Respiratory pump
2
Q
What is the ejection fraction?
A
Measures ability of a heart to produce a cardiac output
Stroke volume/end diastolic volume
3
Q
Why is extraction rate increased in exercise?
A
Distance of diffusion between blood and cells decreases Increased diffusion gradient Increased surface area of capillary bed Increased Bohr and Haldane effect 2,3-DPG
4
Q
What regulates ventilation so that it keeps pace with changing gas levels?
A
Central command Chemoreceptors Muscle and joint receptors Blood potassium Lactic acid Body temperature Hormones
5
Q
What is oxygen deficit?
A
Oxygen demand isn’t met immediately once exercise starts
Breathing remains elevated
6
Q
What is oxygen debt?
A
VO2 is in excess of resting VO2 after exercise
Over ventilation
7
Q
What is the anaerobic threshold?
A
Metabolic demand for O2 exceeds delivery
Muscles conduct glycolysis and produce lactic acid
8
Q
What can be affected by training?
A
Muscle glycolytic and oxidative capacity Muscle capillary density Muscle fibre diameter VO2, CO and SV max O2 debt, anaerobic threshold Decreased resting HR, increased resting SV
9
Q
What is unaffected by training?
A
Resting VO2 Diffusing capacity Max HR CO at rest Haemoglobin conc
