MarksRiser
MarksRiser
AIPMT PRELIMS2010Zoology-Human Physiology

AIPMT PRELIMS 2010 Zoology Respiratory System Multiple Correct Question

Type: Multiple Correct-conceptual-Medium-Class 11

Which two of the following changes (a–d) usually tend to occur in the plain dwellers when they move to high altitudes (3,500 m or more)?

A

Increase in red blood cell size

B

Increase in red blood cell production

C

Increased breathing rate

D

Increase in thrombocyte count

Correct Answer

Option B

Detailed Explanation

When a person moves to higher altitudes the pO₂ and total atmospheric pressure decreases. Hypoxia stimulates the JG⁻cells of the kidneys to release erythropoietin hormone which stimulates erythropoiesis in bone marrow causing polycythemia. Hypoxia will also increase breathing rate. Initially, the size of RBCs will also increase, but will increase in number of RBC the size of RBCs becomes normal.

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