This organ pumps blood

This organ is responsible for the processing of the products of digestion into substances useful to the body?

This organ's main function is to purify the blood by removing nitrogenous waste products and excreting them in the urine.

This organ consists of elastic sacs with branching passages into which air is drawn, so that oxygen can pass into the blood and carbon dioxide be removed.

This organ is a large gland behind the stomach that secretes digestive enzymes into the duodenum.