Peyer's patches

Peyer's patches are small masses of lymphatic tissue found throughout the ileum region of the small intestine. Also known as aggregated lymphoid nodules, they form an important part of the immune system by monitoring intestinal bacteria populations and preventing the growth of pathogenic bacteria in the intestines.

Anatomy

Peyer's patches are oval-shaped areas of elevated lymphatic tissue, measuring between 15 and 30 millimeters in length. They are most numerous in the distal ileum, but can also be found in the jejunum. Each patch is surrounded by a follicle-associated epithelium, which contains specialized cells known as M cells.

Function

The primary function of Peyer's patches is the monitoring of intestinal bacteria and the prevention of the growth of pathogenic bacteria in the intestines. They achieve this through the production of antibodies, which are released into the lumen of the gut. The M cells of the follicle-associated epithelium are responsible for the uptake and transport of antigens from the lumen to the lymphoid tissue, where they stimulate the immune response.

Clinical significance

Peyer's patches play a crucial role in the body's defense against intestinal pathogens. However, they can also be a site of infection and inflammation. Conditions such as Crohn's disease and ulcerative colitis can cause inflammation of Peyer's patches, leading to abdominal pain and other symptoms. In addition, certain pathogens, such as the prion responsible for Creutzfeldt-Jakob disease, can accumulate in Peyer's patches.

See also

• Lymphatic system
• Immune system
• Small intestine