IMMUNOLOGY

Detailed explanation-1: -The circulatory system (cardiovascular system) pumps blood from the heart to the lungs to get oxygen. The heart then sends oxygenated blood through arteries to the rest of the body. The veins carry oxygen-poor blood back to the heart to start the circulation process over.

Detailed explanation-2: -The heart, blood and blood vessels work together to service the cells of the body. Using the network of arteries, veins and capillaries, blood carries carbon dioxide to the lungs (for exhalation) and picks up oxygen. From the small intestine, the blood gathers food nutrients and delivers them to every cell.

Detailed explanation-3: -For example, the respiratory and circulatory systems work together to provide the body with oxygen and to rid the body of carbon dioxide. The lungs provide a place where oxygen can reach the blood and carbon dioxide can be removed from it.