How does the heartbeat and blood vessels change in response to exercise?
During exercise, the heartbeat and blood vessels change in response to the body's increased demand for oxygen-rich blood to the muscles.
Heartbeat:
1. Increases in rate: The heart rate increases to pump more blood to the muscles. It is controlled by the sympathetic nervous system.
2. Increase in strength: The force of the heart's contractions increases to push more blood out of the heart per beat.
Blood vessels:
1. Vasodilation: The blood vessels relax and widen (vasodilation) to increase blood flow to the muscles, reducing resistance to the blood flow within them.
2. Vasoconstriction: The blood vessels that supply blood to the organs that don't have an increased demand for blood selectively constrict, and blood is redirected to the muscles (priority is given to the concerned area as per the demand).
3. Capillary recruitment: The capillaries via angiogenesis increase in number, and dilation gets induced at the site of the heightened demand, which improves blood and oxygen supply to muscle cells.
Overall, these changes are essential for ensuring that the muscles receive the necessary oxygen and nutrients to function correctly during exercise. After exercise, the heartbeat and blood vessels return to their normal state.