What is the structure of the duodenum?

Answer 1

The duodenum is located in your gastrointestinal tract just past the stomach. Some textbooks describe it as being the first part of the small intestine, while others consider it to be a separate organ entirely. Regardless of this debate, the duodenum is a small tube approximately 10 inches long and not more than an inch or two in diameter.

The duodenum is broken in to four parts. These four parts are somewhat arbitrary, and are used mostly by surgeons to enable them to describe the area they are working around in more detail. The entire duodenum is essentially a long tube. At the bottom of the stomach is a small valve known as the gasteroduodenal junction. Just pass this junction is the first part of the duodenum. The first part of the duodenum is located very close to the liver and pancreas.

Approximately 3 inches past the gasteroduodenal junction, the duodenum begins to curve around the pancreas. It is in this area where there is a drain which leads to the bile duct. Bile is drained from the gallbladder into this portion of the duodenum. This aids in digestion of many different types of foods.

Because of the duodenum's close proximity to the gallbladder, gallstones may have an effect on the duodenum. A gallstone which jams into the bile duct can ulcerate into the duodenum, causing a significant obstruction in your gastrointestinal system. This condition is known as gallstone ileus. It can be very painful and is a serious medical condition which often requires surgery to correct.

Any ulceration through the duodenum, which is a form of peptic ulcer disease, can damage many of the organs around the duodenum. The pancreas is one of the most sensitive organs to an ulceration. It is located quite close to the duodenum. As such, a duodenal ulcer can cause significant damage to the pancreas.

The far end of the duodenum leads to another structure known as the jejunum. The jejunum is either the first part of the small intestine, or the second part if you consider the duodenum to be the first part of the small intestine.

Answer 2

The duodenum is the first part of the small intestine located immediately after the stomach. It is a C-shaped tube that is approximately 25-30 cm long and consists of four parts: the superior, descending, horizontal, and ascending parts. These parts are responsible for receiving partially digested food from the stomach and further breaking it down before it moves into the rest of the small intestine for absorption.