What are 3 functions blood serves in the body?

Blood has a number of functions that are central to survival, including: supplying oxygen to cells and tissues. providing essential nutrients to cells, such as amino acids, fatty acids, and glucose. removing waste materials, such as carbon dioxide, urea, and lactic acid.

Explanation:

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.