Pancreatic islets by scarce alpha, delta and PP cells in the periphery, human islets display alpha and beta cells in close relationship with each other throughout the cluster. Islets can influence each other through paracrine and autocrine communication, and beta cells are coupled electrically to six to seven other beta cells (but not to other cell types). The paracrine feedback system of the pancreatic islets has the following structure: A large number of G protein-coupled receptors (GPCRs) regulate the secretion of insulin, glucagon and somatostatin from pancreatic islets, and some of these GPCRs are the targets of drugs used to treat type-2
Esophageal gland Esophageal gland The esophageal glands are glands that are part of the digestive system of various animals, including humans. Esophageal glands in humans are a part of a human digestive system. They are a small compound racemose exocrine glands of the mucous type. There are two types: Each opens upon the surface by a long excretory duct. Oesophageal gland is enlarged in large monoplacophoran species. Oesophageal gland or oesophageal pouch is a part of the digestive system of some gastropods. Oesophageal gland or pouch is a common feature in so-called basal gastropod clades, including Patelloidea, Vetigastropoda, Cocculiniformia, Neritimorpha and Neomphalina.