Oxygen Sensing and Altitude

Question 1

What are the symptoms of altitude sickness?

Answer 1

1500 to 3200m Lightheadedness, headache

2800 to 4600m Insomnia, nausea, vomiting, hyperventilation

4000 to 6500m Severe hyperventilation, anorexia, GI disturbances, pulmonary, cerebral oedema

> 6400m Lethargy, weakness

> 7500m Collapse

9000m Unconsciousness <30 secs

(symptoms vary enormously from person to person)

Question 2

How does altitude sickness affect the body’s performance?

Answer 2

Reduced CNS function:

At 3000m, 30% reduction in visual acuity (? also pressure effect on eye)

At 6000m, 25% reduction in reaction time

Reduced exercise tolerance:

On Everest, VO2max is reduced by 70% (equivalent to an 80 year-old person)

Reduced lactate tolerance (v. high alt.)

Question 3

What is Boyle’s Law?

Answer 3

For a fixed mass of an ideal gas kept at a fixed temperature, pressure and volume are inversely proportional.

If pressure increases, then volume decreases and vice versa, when temperature is held constant.

Therefore, when the pressure is halved, the volume is doubled; and if the pressure is doubled, the volume is halved.

Question 4

What is Charles’ Law?

Answer 4

For a fixed mass of a dry gas, kept at a fixed pressure, temperature in K and volume are directly proportional.

If the temperature is doubled, the volume will be doubled.

Therefore, if the temperature is halved, the volume is halved.

Question 5

What is the equation for Boyle’s Law?

Answer 5

P₁V₁ = P₂V₂

Question 6

What is the equation for Charles’ Law?

Answer 6

V₁T₂ = V₂T₁