MEDICAL PHYSIOLOGY

Detailed explanation-1: -When pancreas sections were double stained for insulin and glucagon, apparently small islets (40–60 m in diameter) showed a segregated cell type distribution with -cells localized in the mantle and -cells in the core of the islets (Fig. 1A and G). In apparently bigger islets (Fig.

Detailed explanation-2: -The islets of Langerhans, first described by Paul Langerhans in 1869, are dispersed throughout the exocrine tissue of the pancreas. Each islet is an endocrine micro-organ consisting of multiple endocrine cell types, the two most prominent and numerous of which are beta and alpha cells.

Detailed explanation-3: -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-4: -The -cells are situated in the islets of Langerhans, which constitute the endocrine part of the pancreas. Throughout the human pancreas there are 1–2 million islets. Although the number of islets is high, they still contribute to less than 2 % of the pancreatic mass.