Islets of Langerhans

The islets of Langerhans are collections of cells scattered throughout the pancreas, the distribution being more in it's tail than in the body and head. They were discovered in 1869 by German pathological anatomist Paul Langerhans. There are one to two million islets in a healthy adult human pancreas which constitute about 2% of the gland's volume.

Functions

The islets of Langerhans form the endocrine part of the gland. They secrete insulin, glucagon, somatostatin and pancreatic polypeptide.

Cell types

Cells in the Islets are classified into four types based on their staining properties and morphology.

	% of total	Secretions
A or α-cells	15-20	Glucagon
B or β-cells	60-75	Insulin
D or δ-cells	3-10	Somatostatin
F cells	3-5	Pancreatic polypeptide