Duodenal bulb

Duodenal Bulb

Illustration of the duodenum, showing the duodenal bulb.

The duodenal bulb is the first part of the duodenum, which is the initial segment of the small intestine. It is located immediately distal to the pylorus of the stomach. The duodenal bulb is approximately 5 cm in length and has a rounded shape, resembling a bulb, hence its name.

Anatomy

The duodenal bulb is situated in the upper part of the abdomen, at the level of the first lumbar vertebra. It is intraperitoneal, meaning it is covered by the peritoneum on all sides, unlike the rest of the duodenum, which is retroperitoneal.

Structure

The duodenal bulb is characterized by its smooth mucosal lining, which is different from the rest of the duodenum that has circular folds known as plicae circulares. The bulb is more susceptible to peptic ulcers due to its exposure to acidic gastric contents.

Relations

The duodenal bulb is anteriorly related to the liver and the gallbladder, while posteriorly, it is related to the pancreas and the bile duct. Superiorly, it is connected to the pylorus, and inferiorly, it continues into the descending part of the duodenum.

Function

The primary function of the duodenal bulb is to receive partially digested food, known as chyme, from the stomach. It plays a crucial role in the initial phase of digestion by mixing the chyme with bile and pancreatic juices, which are essential for the digestion of fats and neutralization of stomach acid.

Clinical Significance

The duodenal bulb is a common site for the development of duodenal ulcers, which are a type of peptic ulcer disease. These ulcers occur due to the erosion of the mucosal lining by gastric acid. Symptoms of duodenal ulcers include abdominal pain, especially when the stomach is empty, and nausea.

Related Pages

• Duodenum
• Small intestine
• Peptic ulcer disease
• Digestive system