Disease of endocrine pancreas
About the pancreas
The pancreas lies behind your stomach, extending laterally from the duodenum toward the spleen. The pancreas is an elongated, pinkish grey organ with a length of about 15cm and weight of about 80g. The broad head of the pancreas lies within the loop formed by the duodenum. The slender body of the pancreas extends toward the spleen, and the tail is short and bluntly rounded. The surface of the pancreas has a lobular texture.
Arterial blood supply includes the branches of the splenic, superior mesenteric and common hepatic arteries. The pancreatic arteries and pancreaticoduodenal arteries are the major branches from these vessels. The splenic vein and its branches drain the pancreas.
The pancreas is primarily an exocrine organ, producing digestive enzymes and buffers. The large pancreatic ducti (Duct of Wirsung) deliver theses secretions to the duodenum. A small accessory pancreatic duct or duct of Santorini may branch from the pancreatic duct. This pancreatic duct extends within the attached mesentery to reach the duodenum, where it meets the common bile duct from the liver and gallbladder. These two ducts empty into the duodenal ampulla, a chamber located roughly halfway along the length of the duodenum.
Functions of the pancreas
The pancreas has digestive and hormonal functions and is known as the only organ in the body to have both endocrine and exocrine secretions. Each day your pancreas secretes abut 1000ml of pancreatic juice. The secretory activities are controlled primarily by hormones from the duodenum. Furthermore, some enzymes are secreted as inactive proenzymes that are activated only after they reach the small intestine. The release of proenzymes rather than active enzymes in the pancreas protects the secretory cells from the destructive effects of their own products.
Carcinoma of the pancreas (Cancer)
Pancreatic carcinoma has become the third leading cause of death in the United States and is known to be the eight most common cancer in women and tenth in men respectively. Pancreatic cancer usually occurs after the age of 50 years and increases in incidence with age, with most patients diagnosed between the ages of 60 and 80 years of age.
Carcinomas occur more often in the head of the pancreas (70%) and body (20%) than in the tail which accounts for 10% of the cases. Carcinoma of the head of the pancreas tend to obstruct the common bile duct early in their course, with resulting jaundice, and can extend into the uncinate processes to involve the superior mesenteric artery and vein, thus compromising surgical respectability. Tumours of the body and tail tend to present later in their course, as they cause few symptoms until they become quite large. Patients with carcinoma of the body or tail of the pancreas typically present with epigastric abdominal pain, profound weight loss, abdominal mass, and early satiety. Due to the vague nature of the symptoms, patients tend to present at later stages, often with distant metastases, particularly in the liver. Microscopically, 90% of pancreatic cancers are adenocarcinomas; the remainder are adenosquamous, anaplastic, or acinar cell carcinomas.
Risk factors of pancreatic cancer includes
- Cigarette smoking has the strongest overall association and is thought to account for one-quarter of cases diagnosed.
- High dietary intake of saturated fat (cream, butter, cheese, pastries, cured meats, chocolate etc.)
- The role of other dietary factors such as coffee, high fat intake and the use of alcohol are still much debated.
- Diabetes mellitus has also recently been identified as a risk factor for the disease.
- Chronic pancreatitis increases the risk of developing pancreatic adenocarcinoma by 10 – 20-fold.
Whipple Procedure (Pancreaticoduodenectomy)
A Whipple procedure is the removal of the head of the pancreas, the entire duodenum, a portion of the jejunum, the distal third of the stomach, and the lower half of the common bile duct, with reestablishment of continuity of the biliary, pancreatic, and GI tract systems. Gastrointestinal continuity is re-established by connecting a portion of the intestine to the bile duct, remaining pancreatic body/tail, and the stomach or duodenum. The procedure may take anything from 6-12 hours, with post operative High care for 7-10 days if no complications arise.
- Martini, F. and Ober, W.C. (2001). Fundamentals of anatomy & physiology: [main volume]. Upper Saddle River, N.J.: Prentice Hall.
- Mcphee, S.J. and Hammer, G.D. (2019). Pathophysiology of disease: an introduction to clinical medicine. 8th ed. New York: Mcgraw-Hill Education Medical.
- Lowe, J.S., Anderson, P.G., Anderson, S.I. and Stevens, A. (2020). Stevens & Lowe’s human histology. Amsterdam: Elsevier.
- www.bartleby.com. (n.d.). Illustrations. Fig. 1062. Gray, Henry. 1918. Anatomy of the Human Body. [Online – Accessed 11 Aug. 2022].
- Edythe Louise Alexander, Rothrock, J.C. and Mcewen, D.R. (2015). Alexander’s care of the patient in surgery. St. Louis, Missouri: Elsevier/Mosby.