Morphological and Histological Study of the Pancreas Gland in the Local Bat ( Pipisterllus kuhlii)

Abstract

The present study aimed to investigate the morphological and histological structure of pancreas in the bat,(Pipistrellus kuhlii). Pancreas was represented by compact pancreatic tissue which is divided into three parts : head , body and tail, its color is whit to yellow. The pancreatic tissue is located in the abdominal cavity near to the mass of intestine in the mesenteric network , which is connected with the coiled region of the duodenum in one side and with the extended mesenteries between the dorsal part of stomach and the abdominal part of spleen from the other side. The pancreas gland is surrounded by a loose connective tissue, the trabeculae are extended from it and divided the gland into many lobules which are different in shape and size . The pancreatic tissue is characterized into two portions: The exocrine portion and endocrine portion , the exocrine portion is represented by compound tubule- acinar gland ,which contains many acini ,and the ductal system , each acinus is represented by a serous secretory unit containing a number of pyramidal cells that surround a small lumen . The ductal system initiated with centeroaciner cells that occupy the acinus center, these cells are connected with intercalary ducts which are connected with intra lobular ducts, these ducts lead to the interlobular ducts, which their diameter is larger than the diameter of intralobular ducts. The interlobular ducts release their secretory contents in the main duct which is opened in the upper part of the duodenum. The endocrine portion is represented by clusters of cells known as Islet's of Langerhans which appeared as a mass of pale coloured cells spread among the exocrine portion units and separated from the exocrine portion by a thin layer of connective tissue. Each islet contains four types of cells arranged as irregular groups separated from each other by a network of blood capillaries, these cells are: Alpha cells ( A-cells),they 're rounded in shape located in the peripheral portion of the islet , Beta cells(B-cells) are oval shaped, lie at the center of the islet , while Delta cells (D-cells) are irregular shaped and faint coloured, located between Alpha and Beta cells, they are less in number and they may appear as a single cells or as small clusters, mostly located at the peripheral portion of the islet