Human Pancreas

The human pancreas is a large digestive and endocrine gland. It is located behind the stomach, on the posterior abdominal wall, on the level of the lower two thoracic vertebrae (T11-T12) and the first upper lumbar (L1). Its long axis lies almost transversely across the vertebral column. One third of this gland is to the right side, while the other two thirds lie to the left of the midplane, in the epigastric and left hypochondriac region.

The length of the pancreas ranges between 16 and 22 cm, while its maximum width varies between 6 and 9 cm in the region of the head. With a thickness of about 3 cm, it weighs about 80 grams in adults. This endocrine organ is composed of three parts arranged next to one another: the head (caput pancreatis), which lies to the right of the spinal column; the body (corpus pancreatis); and a tail (cauda pancreatis). Between the head and the body, there is a small narrow part: the neck.

The head of the pancreas is in contact with the duodenum, being hugged by it in the shape of a horseshoe. Inside this gland and along its longitudinal axis, there is a long conduit or tube; it is the pancreatic duct, which joins the common bile duct right before it enters the duodenum. All the pancreatic digestive juice enzymes are discharged into the duodenum through this duct. Posteriorly, the head of pancreas is in contact the the right renal vein, the renal artery, and the inferior vena cava; the anterior surface of its head, on the other hand, is covered by the parietal peritoneum.

Function

Histologically and physiologically, the pancreas is divided into two parts: the exocrine and endocrine pancreas. The exocrine part secretes important digestive enzymes, like lipase, trypsine, and chimotrypsine, which are released into the duodenum to break down the food we eat so they can be absorbed by the walls of intestine. The endocrine portion is composed by the islets of Langerhans, which produce important hormones whose main function is blood sugar regulation and metabolism.

Below, anterior view of pancreas, with its head in the 'elbow' of duodenum. The stomach, which lies in front, is missing.

Posterior aspect of the same organ. You can see the common bile duct joining the pancreatic duct.