Anatomy and Physiology II Practice Test

During physical exercise, the greatest change in blood flow typically occurs in which area?

1. The brain

2. Skeletal muscle

3. The skin

4. The kidneys

The correct answer is: Skeletal muscle

During physical exercise, the greatest change in blood flow occurs in skeletal muscle. This is primarily due to the increased metabolic demands placed on the muscles during activity. As exercise begins, signals are sent to dilate blood vessels supplying the skeletal muscles, which allows for greater blood flow to enhance the delivery of oxygen and nutrients while also facilitating the removal of metabolic waste products, such as carbon dioxide and lactic acid. The body's overall response to exercise involves the redistribution of blood flow. While the heart rate and total cardiac output increase, the proportion of blood directed to skeletal muscles can increase dramatically, often exceeding 80% of total blood flow during intense physical activity. This is in direct contrast to other areas such as the brain, skin, and kidneys, which receive relatively stable or reduced blood flow during intense exercise due to the prioritization of the working muscles.