Question: what are the major organs of the body system?
Answer: Circulatory system: heart, blood, blood vessels, and lymphatics. Digestive system: esophagus, stomach, small intestine, and colon. Endocrine system: pituitary, thyroid, ovaries, and testes. Immune system: organs (including lymphatics and spleen), special. ...  Integumentary system: skin, hair, nails, and sweat glands.