Pancreatic islets Pancreatic islets The pancreatic islets or islets of Langerhans are the regions of the pancreas that contain its endocrine (hormone-producing) cells, discovered in 1869 by German pathological anatomist Paul Langerhans. The pancreatic islets constitute 1 to 2% of the pancreas volume and receive 10–15% of its blood flow. The pancreatic islets are arranged in density routes throughout the human pancreas, and are important in the metabolism of glucose. There are about 3 million islets distributed in the form of "density routes" throughout the pancreas of a healthy adult human, each of which measures an average of about 0.1 mm (109
Exocrine gland glands contain a glandular portion and a duct portion, the structures of which can be used to classify the gland. Exocrine glands are named apocrine glands, holocrine glands, or merocrine glands based on how their products are secreted. Exocrine gland Exocrine glands are glands that produce and secrete substances onto an epithelial surface by way of a duct. Examples of exocrine glands include sweat, salivary, mammary, ceruminous, lacrimal, sebaceous, and mucous. Exocrine glands are one of two types of glands in the human body, the other being endocrine glands, which secrete their products directly into the bloodstream. The liver and