Fundic glands

Fundic glands, also known as oxyntic glands, are one of the four main types of glands found in the stomach. They are located in the fundus and body of the stomach, the largest sections of the stomach. The fundic glands are unique in that they contain three types of exocrine cells: mucous neck cells, parietal cells, and chief cells.

Structure

The fundic glands are tubular in structure and are lined by a columnar epithelium. The glands are composed of a base and a neck. The base of the gland contains the parietal and chief cells, while the neck is lined by mucous neck cells.

Function

The primary function of the fundic glands is to secrete gastric juice, a mixture of hydrochloric acid, pepsinogen, and mucus. Each type of cell in the fundic glands contributes to this secretion:

• Mucous neck cells produce mucus to protect the stomach lining from the corrosive effects of hydrochloric acid.
• Parietal cells secrete hydrochloric acid, which is necessary for the conversion of pepsinogen to pepsin, and intrinsic factor, which is necessary for the absorption of vitamin B12 in the small intestine.
• Chief cells produce pepsinogen, the inactive form of pepsin. Pepsin is a protease that begins the process of protein digestion in the stomach.

Clinical significance

Abnormalities in the function or structure of the fundic glands can lead to a variety of gastrointestinal diseases. For example, atrophic gastritis can result from the loss of parietal cells, leading to a decrease in hydrochloric acid secretion. This can cause a rise in gastric pH, leading to an environment that favors the growth of certain bacteria and the development of gastric cancer.

Hyperplasia of the fundic glands, known as fundic gland polyps, is a common finding in patients with familial adenomatous polyposis. These polyps are usually benign, but can occasionally become malignant.