The human organ system is comprised of several different systems such as the circulatory, cardiovascular and lymphatic systems. There are also the digestive, endocrine and integumentary systems, notes About.com.
The circulatory system works to transport gases and nutrients to cells and tissues in the body, explains About.com. Blood circulation is what helps accomplish this function. The heart, blood and blood vessels comprise the cardiovascular system. The cardiovascular system is what pumps blood through the body.
The lymphatic system contains the lymph vessel, nodes, thymus, spleen and tonsils. It is a vascular network of ducts and tubules that work to collect, filter and return lymph to blood circulation, says About.com. It is also a component of the immune system through producing and circulating immune cells called lymphocytes.
Breaking down food into smaller particles for the body to use as energy is the function of the digestive system. The primary digestive organs are the mouth, stomach, rectum and intestines. Accessory organs include the teeth, tongue, liver and pancreas, notes About.com.
The function of the endocrine system is to regulate the body's vital processes such as growth, metabolism, sexual development and homeostasis, explains About.com. Endocrine structures include the pituitary, pineal and thyroid glands, as well as the thymus and ovaries or testes.