Speed of blood supply to muscles

2021-05-24 03:23 PM

Changes in blood flow during muscle contraction. Flow increases and decreases with each muscle. At the end of the contraction, the blood velocity increases for a few seconds and returns to normal within a few minutes.

In sports activities, the circulatory system is under a great deal of pressure to supply blood to a large amount of skeletal muscle => blood flow must be large. In addition, the heart must work 4-5 times more than normal and 6-7 times for athletes.

During rest, the average blood flow through the striated muscle is 3-4ml/min/100g.

In athlete training, blood flow increases 25 to 50 times, up to 100-200 ml/min/ 100g. Highest speed up to 400ml/min/100g.

Blood flow during muscle contraction

Changes in blood flow during muscle contraction. Flow increases and decreases with each muscle. At the end of the contraction, the blood velocity increases for a few seconds and returns to normal within a few minutes.

The cause of slower blood flow during muscle contraction is the shortening of blood vessels by muscle contraction. In spasticity, which is a condition in which a blood vessel shortens, blood flow can stop, which rapidly causes rapid weakening of the muscle contraction.

Figure. Effect of muscle training on calf blood flow during rhythmic vigorous contraction. The blood flow during contractions is much less than between contractions.

Increased flow to muscle capillaries during exercise

During rest, muscle capillaries have little or no blood supply. But during exercise, all the capillaries are open. Capillary activity does not reduce the diffusion of oxygen and nutrients from the blood to the tissues. Sometimes it even increases the surface area by 2-3 times.