Explanation:
At very high altitudes, the atmospheric pressure is significantly lower than at sea level. This lower atmospheric pressure affects the oxygen availability in the air, which in turn affects the oxygen-carrying capacity of the blood. Red blood cells, also known as red blood corpuscles or erythrocytes, play a crucial role in carrying oxygen to different parts of the body.

Effect of High Altitude on Red Blood Corpuscles:
At high altitudes, the following changes occur in the red blood corpuscles:

1. Increased Number: The number of red blood corpuscles increases in response to the lower atmospheric pressure. This is known as "polycythemia." The body's natural response to the decreased oxygen levels is to produce more red blood cells to compensate for the reduced oxygen-carrying capacity. The increased number of red blood cells helps to deliver a sufficient amount of oxygen to the body tissues.

2. Increased Size: The red blood corpuscles do not increase in size at high altitudes. The size of red blood cells remains relatively constant and is not influenced by altitude.

It is important to note that while the number of red blood cells increases at high altitudes, this adaptation is temporary. When individuals return to lower altitudes, their red blood cell count gradually returns to normal. The body adjusts to the lower oxygen levels by increasing the production of erythropoietin, a hormone that stimulates red blood cell production. Once individuals return to lower altitudes where oxygen availability is higher, the need for increased red blood cell count diminishes, and the body gradually readjusts.

In summary, at very high altitudes, the red blood corpuscles in the human body will increase in number to compensate for the reduced oxygen-carrying capacity due to lower atmospheric pressure.