RESPIRATORY AND CIRCULATORY SYSTEMFARAH HANI BINTI MUNJIAT 116640

A HEALTHY MALE, AGED 23 YEARS OLD BEAR GRYLLS CLIMBED THE MOUNT EVEREST. PLEASE DESCRIBE THE CHANGES IN HIS CIRCULATORY AND RESPIRATORY SYSTEM

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CLIMBING THE MOUNTAINThe heart pumps faster and blood pressure rises. 

Acute exposure to hypoxia.

Rapid reduction in plasma volume.

Increase in lung capacity.

Red blood cell production increases, resulting in an increased haemoglobin concentration, which is required to pick up oxygen and transport it around the body. 

Increase in cardiac output from about 5 L/min in the resting adult to about 20 L/min.

Increase in production of the enzymes that aid in the release of oxygen to the tissues.

increase in hyperventilation-reduce PACO2 and maintaining PAO2.

Increase in oxygen uptake in the alveolar capillaries.

Heart chamber size expand - increases the heart's stroke volume from 60ml to over 200ml.

Maximal oxygen consumption (VO2max) decreases with increasing altitude.

UPON REACHING THE HIGHEST PEAKAcclimatization- the body will try to adjust to the high altitude

At the top of Mount Everest, the percentage of oxygen in the air is the same as that at sea level (about 20% oxygen).

However, atmospheric pressure decreases as altitude increases, and the atmospheric pressure at the summit of Everest is 33% that of sea level. Therefore, there is 66% less oxygen than there is at sea level.

At altitude of 1500m, increase in the frequency and depth of breathing. 

Maximal oxygen consumption on the summit is extremely low with the result that climbers are critically vulnerable to unexpected setbacks such as changes in the weather.

UPON REACHING THE HIGHEST PEAKEnormous hyperventilation which is necessary to maintain the alveolar PO2 at viable levels.

At sea level our blood is 98% saturated with oxygen and this decreases to 89% at 3000m and reaches as low as 40% on the summit of Everest.

Above 26,000 feet (8000 m), which on Everest is known as the "death zone." At this altitude, the human body is unable to acclimate to the low oxygen and begins to deteriorate. Most climbers must use oxygen and will have difficulty sleeping.

Exposure to hypobaric hypoxia produces pulmonary vasoconstriction resulting in pulmonary hypertension proportional to the degree of hypoxia.

Periodic breathing when sleeping at high altitude.

Tolerance to extreme altitude is critically dependent on barometric pressure.

Effects of hypoxia on systemic and pulmonary circulation

The graph below compares the amount of oxygen available in a given volume of air at altitude relative to

the amount at sea level for the same volume.

IF HE WERE TO SUFFER FROM HYPOXIA/HIGH ALTITUDE SICKNESS. WHAT ARE HIS SYMPTOMS AND WHAT ARE THE POSSIBLE TREATMENT?

SYMPTOMSDizzyness or fainting (syncope)

Shortness of breath (dyspnea)

Confusion, lethargy, and/or lack of judgment

Headache

Rapid heart rate (tachycardia)

Elevated respiratory rate (tachypnea)

Euphoria and a sense of well-being

Tingling, warm sensations

Elevated blood pressure (hypertension)

Lack of coordination

Visual changes, such as tunnel vision

Elevated red blood cell count (polycythemia) in people with chronic hypoxia

A bluish tinge to the lips and extremities (cyanosis)

TREATMENT FOR HYPOXIAOxygen therapy if you are short of breath or having other symptoms suggestive of moderate or severe hypoxia. If your symptoms are severe, mechanical ventilation with a ventilator may be needed.

Climb down (descend) to a lower altitude as rapidly and safely as possible. You should not continue climbing if you develop symptoms.

If a person cannot descend due to weather or other conditions, then hyperbaric therapy with a Gamow bag or other hyperbaric bag should be initiated, if available.

Acetazolamide (Diamox) may be given to help you breathe better. It can help reduce mild symptoms. This medicine can make you urinate more often. Make sure you drink plenty of fluids and avoid alcohol when taking this drug. This medication works best when taken before reaching a high altitude

Undergo health check-up

• Bronchoscopy • CT or MRI of your head• Echocardiogram• X-ray or a CT of your chest• EKG• Blood test

MAN VS WOMANYes, there are differences between male and female hiker in terms of respiration and blood circulation during hiking due to certain physical factors.

• Women have smaller lung than men's. • Size of the heart and major blood vessels of women are smaller than

those of men of the same race and age• In general, a man's heart is as much as 25% larger than a woman's

heart - larger capacity for speed and strength• Women also have narrower airways (breathing tubes), which means it’s

harder to move air in and out of the lungs. • During strenuous exercise a woman breathe around 120 litres of air per

minute, compared to elite male athlete who can breathe as much as 240 litres per minute.

• Because women are unable to 'heavy breathe' in response to strenuous exercise, they may experience a drop in the amount of oxygen in their blood and a corresponding increase in their breathlessness.

• Edema is more common in female due to hormones and menstrual cycles