Tissue metabolism

Energy demand varies among the organs. Their microcirculation is well adapted, as tissues with higher metabolic demands like the brain, muscle and the myocardium present with a high density of capillaries.

The skeletal muscle, for example, may increase its energy expenditure eight-fold with exercise compared with rest which is achieved by two mechanisms: by a high number of capillaries increasing blood flow, and by an increase of the oxygen extraction ratio leading to a lower venous pO2 at exercise compared with an individual at rest.

0 0

Post a comment