What Is Serotonin Secreted By?

Serotonin, an essential neurotransmitter in the human body, is most commonly associated with its effects on the central nervous system, especially the brain. It is secreted by neurons, nerve cells, and other internal organs. Different types of serotonin receptors determine how the transmitter is used by organs and muscles.

Gastrointestinal Tract

• Serotonin is found in large amounts in the enterochromaffin cells of the gastrointestinal tract. As much as 90 percent of the body's supply is found here.

Blood Platelets

• The serotonin secreted by platelets facilitates blood clotting. An injury to the body sets off a cascade of biochemical processes, one of which causes platelets to secrete their store of serotonin.

Central Nervous System

• The brain is rich in neurons which secrete serotonin. Its presence in the central nervous system governs muscle contraction and mental state.