What is Peyer's Patch?
Peyer's patches are essential components of your immune system. They are groups of lymphatic tissue, specifically lymphoid follicles, located in the small intestine, primarily in the ileum (the last section) and sometimes the jejunum and even the duodenum.
- Location: Primarily found in the distal portion of the small intestine (ileum), they can also be present in the jejunum and, less frequently, the duodenum. They're situated along the antimesenteric border of the intestine.
- Structure: These patches are organized aggregates of lymphoid follicles, roughly egg-shaped, and contain numerous immune cells. They are a key part of the gut-associated lymphoid tissue (GALT).
Function
Peyer's patches play a crucial role in immune surveillance and response within the gut. They are involved in:
- Antigen sampling: Specialized cells called M cells transport antigens (foreign substances) from the intestinal lumen across the epithelium to underlying immune cells within the Peyer's patch.
- Immune response initiation: Once antigens are presented, the immune cells in the Peyer's patch initiate an immune response, producing antibodies (like IgA) and initiating other immune responses to fight off pathogens. This process involves B cell activation, B-cell receptor (BCR) affinity maturation, and the generation of memory cells.
- Mucosal immunity: They contribute significantly to the overall mucosal immunity of the gut, protecting against harmful bacteria and other pathogens.
Key Characteristics Summarized
- Lymphoid follicles: Organized clusters of immune cells.
- Small intestine location: Predominantly in the ileum, sometimes the jejunum and duodenum.
- Gut-associated lymphoid tissue (GALT): A significant component of the GALT system.
- Antigen sampling and immune response: Crucial for initiating immune responses against ingested antigens.
References: The information above is synthesized from numerous sources, including but not limited to the provided links such as StatPearls, ScienceDirect, Healthline, Wikipedia, and ImmuseHealth. These sources consistently describe Peyer's patches as lymphoid follicles in the small intestine that play a vital role in gut immunity.
