Muscular system and Cardiovascular system

Muscular system Absorbed calcium, potassium, and sodium are needed for muscle contraction; the lactic acid produced by working muscles is converted to glucose in the liver.

Cardiovascular system and blood Absorbed water maintains blood volume; iron is used in red blood cells to make hemoglobin; vitamin K made in the colon is used in clotting; many plasma proteins are made in the liver. Immunity and the

lymphatic system Gastric juice and stomach enzymes help destroy microorganisms; diarrrhea helps flush microbes from the intestines.