Pancreas

Abstract

Similar to the compact pancreas of the dog, cat, man, and other primates, and dissimilar to the diffuse tissue in rats and rabbits, the avian pancreas is a discrete lobular structure that usually has well-defined clefts or morphologic folds (Figure 21–1). This organ, weighing between 2.5 and 4.0 g in adult chickens, is suspended within the U-shaped duodenal loop of the small intestine and is responsible for two families of secretions, the digestive enzymes (exocrine) and the protein-aceous hormones (endocrine). The exocrine (acinar) tissue synthesizes and releases enzymes into at least three discrete pancreatic ducts, conveying them to the duodenal loop where all semiliquid foodstuffs are subjected to the powerful lipolytic, proteolytic, and amylolytic enzymes (Chapter 10). The avian pancreas also synthesizes and releases directly into the bloodstream peptide hormones which emanate from scattered islet (endocrine) tissue embedded within the sea of acinar tissue.