The transport system in human beings mainly involves heart, blood and blood vessels.Functions of these are:
(i) Function of heart :The heart pumps oxygenated blood to all cells of the body.Also, during cellular respiration,the blood gets deoxygenated due to the release of \( CO_2 \) from cells so, the heart receives deoxygenated blood from the body parts and sends the deoxygenated blood to lungs for purification/oxygenation.
(ii) Function of blood : Blood helps in the transport of oxygen to the cells, exhaling carbon dioxide by picking it from cells, transport of nutrients and nitrogenous waste like urea. It also helps in the protection of the body from diseases and regulation the body temperature.
(iii) Function of blood vessels : The blood pushed by the heart flows through the blood vessels (arteries, veins and capillaries) and are responsible for carrying blood through the tissues and organs.