(a) What are the immediate effects of exercise on the functions of (i) the heart, (ii) the lungs, (iii) the liver?
(b) How do these changes help to meet the needs of exercise?
a) Exercise enhances the heart rate and the volume of blood expelled at each contraction (stroke volume); the rate and depth of breathing enhance; the liver changes more glycogen to glucose.
b) These changes supply the extra oxygen and glucose that the active muscles require for their enhanced respiration. The extra carbon dioxide from respiration is deleted as fast as it accumulates