Final answer:
Perfusion refers to the adequate circulation of blood within an organ or tissue, facilitated by the human circulatory system's network of blood vessels to meet cellular demands for oxygen, nutrition, and waste removal.
Step-by-step explanation:
Circulation of blood within an organ or tissue in adequate amounts to meet the cells' oxygen, nutritional, and waste-removal needs is termed perfusion. The human circulatory system is responsible for the transport of oxygen and nutrients to cells and removing carbon dioxide and waste products. Blood flow must be regulated and redirected to meet the varying demands of different tissues during activities such as exercise or digestion.
Through a network of blood vessels, including arteries, veins, and capillaries, blood carries out this vital role effectively. For example, during exercise, more blood is pumped to the muscles, whereas after eating, blood flow increases to the digestive system. The brain, however, maintains a consistent level of blood supply. This ability to direct and manage blood flow allows the circulatory system to respond efficiently to the body's changing needs, ensuring optimal functioning of all cells, tissues, and organs.