CLIMBING THE EVEREST

PHYSIOLOGICAL CHANGES IN THE CLIMBER’S CARDIOVASCULAR AND

RESPIRATORY SYSTEM

BACKGROUND INFORMATION

• The climber is a healthy male, 20-30 years old

• He will climb to the highest peak of the Mt Everest, at 8,848m above sea level (29,029ft)

During the climb

• Increased heart rate• Increased stroke volume (amount of blood

ejected per beat)• Increased cardiac output (volume of blood

pumped in 1 minute, L/min)• Increased blood flow to muscle tissues (less

for other organs)• Increase in systolic pressure

During the climb

• Increased respiration/breathing rate

• Increased in tidal volume: the quantity of air that is inhaled and exhaled with every breath

After reaching Peak XV (8,848m above sea level)

Shortly after:• Increased breathing rate• Increased heart rate• Slight decrease in stroke volume

After reaching Peak XV (8,848m above sea level)

Long enough for acclimatization:• decreased blood plasma volume • increased hematocrit• higher concentration of capillaries in skeletal

muscle tissue• increased myoglobin• Increased red blood cell mass

If the climber suffers hypoxia/ altitude sickness

Symptoms:• Lack of appetite, nausea, or vomiting• Fatigue or weakness• Dizziness• Insomnia• Persistent rapid pulse• General malaise

Possible treatments

• Oxygen enrichment for mild to moderate cases

• Use Gamow bag, a portable plastic hyperbaric chamber inflated with a foot pump

• Acetazolamide, can help to quickening altitude acclimatization

Bonus question

Would it make any difference if the climber is a female?Yes, because males typically have:• larger tracheae and branching bronchi, with

about 56% greater lung volume per body mass• greater oxygen-carrying capacity; larger

hearts, 10% higher red blood cell count, higher haemoglobin