Environmental Effects on the Body Systems

Question 1

What is the definition of altitude?

Answer 1

the height or elevation of an area above sea level

Question 2

What is the definition of humidity?

Answer 2

The amount of water vapour in the atmospheric air

Question 3

What is the definition of barometric pressure?

Answer 3

The pressure exerted by the earths atmosphere at any given point

Question 4

What is the definition of partial pressure?

Answer 4

The pressure exerted by an individual gas held in a mixture of gases

Question 5

What is the definition of diffusion?

Answer 5

The movement of gas across a membrane down a gradient from an area of high to low concentration/pressure

Question 6

What is the relationship between altitude and partial pressure?

Answer 6

-As altitude increases, barometric pressure decreases. The composition of air remains the same however, the partial pressure of pO2 decreases
-The greater the altitude, the greater the negative impact on the diffusion gradient

Question 7

What is the partial pressure of O2 in the alveoli and capillaries at rest?

Answer 7

alveoli - 105
capillary - 40

Question 8

What is the partial pressure of CO2 in the alveoli and capillaries at rest?

Answer 8

alveoli - 40
capillary - 46

Question 9

What are the short term effects of altitude on the CV and respiratory system?

Answer 9

-Rate of oxygen diffusion decreases, reducing haemoglobin saturation, which results in poor transport of O2 to the muscles for aerobic energy production
-Breathing frequency increases both at rest and during exercise in an attempt to maintain oxygen consumption
-Blood volume decreases, plasma volume decreases by 25% to increase the density of RBC’s
-Stroke volume decreases during sub-maximal exercise, which increases heart rate
-Maximal cardiac output, stroke volume, heart rate decrease during maximum intensity exercise

Question 10

What are the implication of altitude on performance?

Answer 10

-Reduction in aerobic capacity/ VO2 max impacting on both intensity and duration an athlete can preform
-Little impact up to 1500m but thereafter every 1000m increase in altitude VO2 may drops but around 8-11%
-At the summit of Everest an athletes VO2 can drop to just 15ml/kg/min compared to 65ml/kg/min at sea level
-Greater demand on anaerobic energy systems to maintain energy production
-Increased lactic acid production at any sub max intensity and early on set fatigue

Question 11

What are the acute effects of high alititude on the CV and respiratory systems?

Answer 11

Decreased pO2 in the air
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Decreased diffusion gradient to the capillary blood
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Decreased haemoglobin and O2 association in the blood stream
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Decreased O2 transportation to the muscle tissue
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Decreased diffusion gradient to the muscle tissue
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Decreased O2 supply for aerobic energy production
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Increased breathing frequency, decreased blood volume and SV, and increased HR
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Decreased VO2 max, aerobic capacity, intensity and duration of aerobic performance before fatigue