Excercising muscle will receive more oxygen from hemoglobin than will relaxed muscle because:
a)it's PO2 is low
b)it's PCO2 is high
c)both a and b
d)both a and b and its temp is higher than usual
The correct answer is c) both a and b.
When exercising, the muscle cells require more oxygen to meet the increased energy demands. The increased oxygen delivery is achieved through several factors:
a) The partial pressure of oxygen (PO2) in the muscle tissue decreases during exercise. This happens because the muscles consume oxygen at a faster rate than it can be replenished, leading to a lower oxygen concentration. As a result, the hemoglobin in red blood cells readily releases oxygen in areas of lower PO2, increasing the oxygen availability to the exercising muscle.
b) The partial pressure of carbon dioxide (PCO2) in the muscle tissue increases during exercise. This occurs as a byproduct of increased metabolic activity, as the muscles generate more carbon dioxide. Higher levels of PCO2 cause the blood vessels in the muscle tissue to dilate, allowing a greater blood flow and oxygen delivery to the muscles.
Therefore, both the low PO2 and high PCO2 in exercising muscle help facilitate a greater oxygen delivery from hemoglobin, ensuring that the energy demands of the active muscles are met. The temperature of the muscle (option d) does increase during exercise, but it is not directly related to the increased oxygen delivery.