Final answer:
The pancreas is a 15-centimeter-long heterocrine gland located behind the stomach, with both exocrine and endocrine functions. Its exocrine part aids digestion by releasing enzymes, while the endocrine part includes pancreatic islets that produce hormones like insulin and glucagon.
Step-by-step explanation:
Gross Anatomy and Cellular Structure of the Pancreas
The pancreas is a vital organ located in the upper abdomen, tucked behind the stomach. It is roughly 15 centimeters (6 inches) long with a soft, oblong shape, and is divided into three main sections: the head, body, and tail. The head of the pancreas is nestled into the curve of the duodenum while the tail extends towards the spleen.
Functionally, the pancreas is known as a heterocrine gland, meaning it performs both exocrine and endocrine functions. The exocrine tissue releases digestive enzymes into the pancreas, helping in digestion. Meanwhile, the endocrine tissue, grouped into clusters known as the pancreatic islets or islets of Langerhans, is responsible for releasing hormones like insulin and glucagon directly into the bloodstream.
The pancreatic islets contain four types of cells, each producing different hormones: alpha cells secrete glucagon, beta cells produce insulin, delta cells secrete somatostatin, and PP cells or F cells produce pancreatic polypeptide.