Week 9 - Exercise and Altitude

Question 1

What is consider altitude?

Answer 1

Above 3000m above sea level

Question 2

What is hypoxia?

Answer 2

Inadequate supplu of oxygen to repsiring tissue (irrelevant based on height)

Question 3

How are altitude and hypoxia linked and why?

Answer 3

Altitude provides a hypoxic environment 
High altitude
-decrease ambient temp
-increase solar radiation
-decrease barometric pressure (decrease pressure due to less mass above pushing down)

Question 4

What is Dalton’s Law?

What happens at altitude?

Answer 4

The total pressure exerted is equal to the sum of the partial pressure of the individual gases.
At altitude partial pressures drop (% of gases remains the same)

Question 5

What are the types of hypoxia + describe them?

Answer 5

Hypobaric hypoxia- reduced pressure (altitude)

Normobaric hypoxia- reduced oxygen content (normal pressure)

Question 6

Describe normoxia and hyperoxia

Answer 6

Normoxia- normal oxygen pressure (sea level)

Hyperoxia- high oxygen pressure

Question 7

Describe the oxygen cascade process?

Answer 7

The fall in PO2 reduces the driving pressure for gas exchange in the lungs (decrease pressure gradient) and in turn produces a cascade of effect to the level of the mitochondria

Question 8

What effect does altitude have on O2 saturation?

Answer 8

O2 saturation decreases as altitude increases, due to the oxygen cascade process

Question 9

What are normal haemoglobin (Hb) conc for healthy males and females?
How much O2 can 1g of Hb transport?

Answer 9

150g and 130g per L of blood, males and females respectively

1 Hb can transport 1.34 ml

Question 10

What are the three types of altitude sickness?

Answer 10

Mild altitude sickness (acute mountain sickness, AMS)
High altitude pulmonary oedema (HAPE)
High altitude cerebral oedma (HACE)

Question 11

Describe acute mountain sickness

Answer 11

Symptoms
-Headache
-Nausea
-Fatigue
Causes
-Ascending faster than 500m/day
-Exercising vigorously at altitude

Question 12

Describe high altitude pulmonary oedema (HAPE)

Answer 12

Develops 2-3 days at altitude
Can be fatal within hours
Accumulation of fluid in the lungs that prevents the air spaces from opening up (harder to increase vol.) and filling with fresh air with each breath.
Symptoms
-Excess fluid in the lings
-Breathless
-Fever
-Coughing frothy spit
Causes
-Ascending faster than 500m/day
-Exercising vigorously at altitude

Question 13

Describe high altitude cerebral oedema (HACE)

Answer 13

An increase in blood flow to the brain is a normal responcse to low O2 levels, However if the blood bessels in the brain are damaged, fluid may leak out and result in swelling of the brain.
Symptoms
-Severe headache
-Vommiting, confussion, drowsiness
-Coma
Causes
-Ascending faster than 500m/day
-Exercising vigorously at altitude

Question 14

What are the immediate responses to altitude?

Answer 14

• Hyperventilation
• Increase blood flow during rest and sub-max exercise
• Increase resting systolic BP
• Increase EPO

Question 15

What are the long term responses to altitude?

Answer 15

Increased O2 carrying capacity

• Increased EPO is not along term response but lead to:
• initial decrease in plasma vol.
• Increase TBC and Hb synthesis