GENERAL HISTOLOGY

Detailed explanation-1: -In small human islets (40–60 m in diameter), -cells had a core position, -cells had a mantle position, and vessels laid at their periphery. In bigger islets, -cells had a similar mantle position but were found also along vessels that penetrate and branch inside the islets.

Detailed explanation-2: -Alpha cells are most commonly found on the dorsal side of the pancreas and are very rarely found on the ventral side of the pancreas. Alpha cells are typically found in compact Islets of Langerhans, which are themselves typically found in the body of the pancreas.

Detailed explanation-3: -Islets of Langerhans are islands of endocrine cells scattered throughout the pancreas.

Detailed explanation-4: -They are composed of several types of cells. At least 70 percent are beta cells, which are mostly localized in the core of the islet. These cells are surrounded by alpha cells that secrete glucagon, smaller numbers of delta cells that secrete somatostatin, and PP cells that secrete pancreatic polypeptide (figure 1).

Detailed explanation-5: -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.