Diffuse Endocrine Glands: Placenta, GI Tract, Kidney and Heart

J. Diffuse endocrine glands - Placenta : Several organs beyond the named glands secrete hormones diffusely, without forming a single compact gland. The placenta, the intimate physiological-exchange link between foetus and the mother's uterine wall, is a temporary endocrine gland: during pregnancy it secretes estrogen, progesterone, human Chorionic Gonadotropin (hCG) and human placental progesterone, all of which check contraction of uterine muscle and maintain the thickness of the uterine endometrium, together maintaining the pregnancy -- and hCG's presence in a urine sample is exactly what a pregnancy test detects.

Gastro intestinal tract : The gastrointestinal mucosa also contains scattered endocrine cells producing hormones vital to digestion: gastrin stimulates the gastric glands to produce gastric juice; secretin is responsible for triggering secretion of pancreatic juice from the pancreas and bile from the liver; cholecystokinin (CCK) and pancreozymin (PZ) together stimulate the pancreas to release its enzymes and stimulate the gall bladder to release bile; and entero-gastrone (gastric inhibitory peptide/GIP) slows gastric contractions and inhibits gastric juice secretion. …