Location, Shape, Structure, and Functions of the Pancreas

The pancreas is a vital organ located in the upper left part of the abdomen, playing a key role in both the digestive and endocrine systems. Positioned behind the stomach, it is closely related to several important anatomical structures such as the common bile duct, inferior vena cava, hepatic portal vein, abdominal aorta, and the spine. Its right side is surrounded by the duodenum, while its left end is adjacent to the spleen.

Externally, the pancreas resembles a large tadpole in shape, measuring approximately 17–20 cm in length. The wider right portion is known as the head of the pancreas. When this area enlarges, it may lead to complications such as obstructive jaundice, ascites, and splenomegaly. Moving leftward, the narrower section is referred to as the neck, followed by the body—making up the majority of the gland—and finally, the tail, which extends slightly upward and tapers off.

Anatomically, the pancreas consists of a thin layer of connective tissue covering its surface, which extends into the organ's interior. Within the pancreatic tissue are numerous acini, interlobular ducts, islets of Langerhans, and capillaries. About 80%–85% of the pancreas is made up of acinar cells that produce enzyme-rich pancreatic juice. These enzymes are crucial for breaking down food components like carbohydrates, proteins, and fats. The interlobular ducts collect this fluid and transport it through two main channels: the pancreatic duct running from the tail to the head, and the accessory pancreatic duct located in the upper part of the head. Both ducts connect to the duodenum, allowing the release of pancreatic secretions for digestion. Scattered among the acini are the islets of Langerhans, which account for about 1% of the pancreas' volume. These islets contain hormone-producing cells such as alpha and beta cells, responsible for regulating blood sugar levels.

The pancreas performs three major functions: digestion, glucose regulation, and inhibition of excessive system activity. As a dual-function gland, it operates through both exocrine and endocrine mechanisms.

In terms of digestion, the exocrine function involves the secretion of alkaline pancreatic juice containing various digestive enzymes and bicarbonate. This process is activated during meals and helps neutralize stomach acid entering the small intestine, protecting the intestinal lining while facilitating nutrient breakdown.

Regarding glucose regulation, the endocrine system of the pancreas relies on the islets of Langerhans. Alpha cells secrete glucagon, which increases blood sugar by promoting glucose production, while beta cells release insulin to lower blood sugar by enhancing glucose utilization.

Lastly, the inhibitory function is managed by specialized cells within the islets. PP cells produce pancreatic polypeptide, which suppresses digestive activity under conditions such as high-protein diets, fasting, or physical exertion. D cells secrete somatostatin, which not only inhibits digestion but also controls excessive hormone secretion from other islet cells.

Understanding the structure and roles of the pancreas can provide valuable insight into maintaining metabolic balance and overall health.