Peyer's patches

Small lymphatic tissues found in the small intestine that play a vital role in immune surveillance.

Clusters of lymphoid follicles located in the mucosal layer of the ileum, which is the last part of the small intestine. Peyer's patches are an essential component of the immune system, primarily involved in monitoring intestinal bacteria and preventing the growth of pathogenic bacteria in the intestines. They contain specialized immune cells that respond to the presence of antigens.

Terminologia Anatomica

noduli-lymphoidei-aggregati-intestinales

System

Immune system

Function

Peyer's patches serve a crucial function in the immune system, specifically in the gut-associated lymphoid tissue (GALT). They act as a surveillance mechanism, monitoring the intestinal lumen for harmful pathogens while allowing the passage of nutrients. When foreign antigens are detected, these lymphoid tissues initiate an immune response that helps produce both antibodies and T-cells, which are vital for defending against infections. This immune response is essential for maintaining the balance of the gut microbiota, ensuring the intestinal environment remains healthy and preventing dysbiosis, which can lead to various gastrointestinal disorders. Additionally, Peyer's patches play a role in establishing immune tolerance, helping the body to recognize beneficial microbes without mounting an aggressive immune response.

Location

Peyer's patches are primarily located in the ileum, the last segment of the small intestine, specifically in the mucosal layer that lines the intestinal wall. They are typically situated in clusters with varying numbers, ranging from a few to over a hundred in any given individual. Each cluster consists of multiple lymphoid follicles and is strategically positioned to intercept antigens that pass through the intestinal epithelium. This localization allows them to efficiently monitor and respond to the microbial content of the intestinal tract, ensuring a rapid immune response when necessary.

Did You Know?

Peyer's patches were named after the Swiss anatomist, Johann Conrad Peyer, who described them in the 17th century.
They are more abundant in young individuals and tend to decrease in number with age.
Peyer's patches can also be influenced by dietary changes, which can alter the composition of gut microbiota and affect immune responses.