PATHOLOGY

Detailed explanation-1: -The normal human pancreas contains about 1 million islets. The islets consist of four distinct cell types, of which three (alpha, beta, and delta cells) produce important hormones; the fourth component (C cells) has no known function.

Detailed explanation-2: -The total number of islets in a human pancreas has been estimated to be between 3.2 and 14.8 million, with a total islet volume of 0.5 to 2.0 cm3 [9, 10, 11, 12, 13, 14]. The cellular composition and architecture of pancreatic islets differ between and within species [15, 16].

Detailed explanation-3: -Islets of Langerhans are three-dimensional clusters of approximately 1000 cells that constitute the endocrine portion of the pancreas, and each islet is around 50–500 m in diameter.

Detailed explanation-4: -The islets of Langerhans contain four cell types that each secrete a different peptide: alpha cells secrete glucagon, beta cells secrete insulin, delta cells secrete somatostatin, and P (F) cells secrete pancreatic polypeptide.

Detailed explanation-5: -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 1–2% of the pancreas volume and receive 10–15% of its blood flow.