Besides the major endocrine organs, pockets of hormone-producing cells are found in fatty tissue and in the walls of the small intestine, stomach, kidneys, and heart-organs whose chief functions have little to do with hormone production. in addition, the placenta, which is a structure in the uterus of pregnant women, plays an endocrine role.

Stomach - Gastrin. Gastrin is a peptide hormone that stimulates secretion of gastric acid by the parietal cells of the stomach and aids in gastric motility.

Intestines - Cholecystokinin Secretin; cholecystokinin is a peptide hormone of the gastrointestinal tract that is responsible for stimulating the digestion of fat and protein, while Secretin is a hormone whose primary role is to stimulate the pancreas to secrete digestive fluids that are rich in bicarbonate and neutralize the acids from the stomach as they pass into the small intestine.

Kidney produces hormones; Erythropoietin, active vitamin D3

Heart produces hormone Atrial Natriuretic peeptide

Placenta releases hormones such as; Relaxin, Human Chronic Gonadotropin