What is Peyer's Patch?
Peyer patch is a type of organized lymphoid follicles. Swiss anatomist Johann Conrad Peyer discovered these follicles. Lymphoid follicles make groups of themselves in the mucus membrane. Lymphoid follicles are organs of the lymphatic system. The group of lymphoid follicles in the mucus membrane forms the Peyer's patch. It has a vital role in the digestive system. Peyer's patch works in the immune surveillance of the digestive system to prevent bacterial growth in the intestines. The human immunity system is vital for living a healthy life. The immunity of the digestive system is also essential. Peyer patch is part of the immune system of the digestive system. In this article, we are going to discuss Peyer's patch in detail.
Peyer's Patches Location
Peyer's patches are the groups of lymphoid follicles formed in the mucus membrane of the intestine. Peyer's patches are mainly located in the small intestine of the human digestive system. They are explicitly found in the ileum area, which is the last portion of the small intestine. The ileum absorbs nutrients and water from food. As the intestine is a significant part of the digestive system and the food is digested here, the Peyer's patches play a vital role.
Peyer's Patches Function
Now, we are going to discuss the function of Peyer's patches. Peyer's patches are small function groups of lymphoid follicles, which are also known as lymphoid nodules. They play a vital role in the immunity of the digestive system. They monitor the bacteria present in the intestine and prevent their growth. Thus the intestine and the entire digestive system becomes protected.
Structure of Peyer's Patches
Peyer's patches are the groups of lymphoid follicles. They are located at the edges of the intestine. They have a specific structure to protect the digestion system. A particular epithelium of follicles covers the Peyer's patches. The cover of the Peyer's patches contains microfold cells, which are known as M cells. These cells play a vital role in preventing the growth of pathogens. Microfold cells pass the antigens from one part to another part of the immunity system. Besides the epithelium cover, there are some other structural parts of the Peyer's patches. The structure of Peyer's patches helps them to protect the digestive system.
How Does Peyer's Patch Work?
The primary function of Peyer's patch is to analyze the pathogens in the intestine and prevent their growth. In the lining of the Peyer's patches, the microfold cells absorb the antigens from the microbes in the intestine. The microfold cells lymphoid pass the antigens to the lymphoid tissues. Macrophages absorb the antigens further from the lymphoid tissues. Then the antigens are presented to B and T lymphocytes for preventing growth. If the lymphocytes find any antigen harmful, they trigger the immune response and create respective antibodies. The antibodies turn into pathogen-Killing cytotoxic T lymphocytes. Also, they are migrated through lymphatic vessels and alert the entire immune system. In response, the body produces complete body protection against pathogens so that the digestion system stays healthy along with other systems of the human body.
Hypertrophied Peyer's Patches
Peyer's patches play an essential role in the immunity of the digestive system. Though Peyer's patches are vital for the immune response, their excessive presence can harm the digestive system. The growth of lymphoid tissues in Peyer's patches is called hypertrophied Peyer's patches. It can cause the risk of prion diseases. Therefore, having more than normal Peyer's patches is harmful.
Peyer's Patches Small Intestine
Usually, Peyer's patches are located in the intestine. Most of Peyer's patches are found in the small intestine. The specific location of the patches is the ileum. As the vast part of food is digested in the small intestine, its immunity is essential.
Peyer's Patches Large Intestine
Some of Peyer's patches are located in the large intestine. The end part of digestion is completed in the large intestine. Therefore, the Peyer's patches of the large intestine protect it from harmful pathogens.
Did You Know?
Now, we are going to discuss some facts about Peyer's patch.
Peyer's patches are known as aggregated lymphoid nodules because they are small masses of lymphoid follicles.
The microfold cells present in the cover of the Peyer's patches are the main parts to provide immunity to the digestive system.
The excessive presence of Peyer's patches can lead to the risk of prion diseases.
FAQs on Peyer Patch
1. What are Peyer's patches and where are they located in the human body?
Peyer's patches are organised clusters of lymphoid follicles, which are a crucial component of the body's immune system. They are strategically located in the wall of the small intestine, specifically in the lowest section known as the distal ileum. Functioning as immune sensors, they are a primary example of Gut-Associated Lymphoid Tissue (GALT).
2. What is the primary function of Peyer's patches in the immune system?
The main function of Peyer's patches is immune surveillance of the contents within the small intestine. They actively monitor the intestinal lumen to identify and neutralise potentially harmful pathogens like bacteria, viruses, and other antigens before they can cause infection. They achieve this by capturing antigens and presenting them to immune cells, thereby triggering a localised immune response to protect the digestive tract.
3. What are the main cell types in Peyer's patches and how do they work together?
Peyer's patches contain a specialised mix of immune cells that cooperate to initiate an immune response. The key cell types include:
- Microfold cells (M-cells): These are unique epithelial cells that transport antigens from the intestinal lumen directly to the lymphoid tissue below.
- B-lymphocytes: Found in germinal centres, these cells produce antibodies to neutralise pathogens.
- T-lymphocytes: Located in the areas between follicles, these cells help coordinate the immune response and can directly kill infected cells.
- Dendritic cells and Macrophages: These are antigen-presenting cells that process the antigens brought in by M-cells and present them to T-lymphocytes to kickstart the adaptive immune response.
4. What is the role of Peyer's patches during a typhoid infection?
In a typhoid infection, Peyer's patches are specifically targeted by the bacterium Salmonella typhi. The bacteria invade the M-cells of the Peyer's patches to enter the body. Once inside, they multiply within the lymphoid tissue, leading to severe inflammation, swelling, and ulceration of the patches. This can result in abdominal pain and, in severe cases, intestinal perforation, which is a life-threatening complication of typhoid fever.
5. Why are Peyer's patches classified as a secondary lymphoid organ?
Peyer's patches are classified as secondary lymphoid organs because they are the sites where mature lymphocytes become activated. The immune system has two types of lymphoid organs:
- Primary lymphoid organs (e.g., bone marrow and thymus) are where lymphocytes are produced and mature.
- Secondary lymphoid organs (e.g., spleen, lymph nodes, and Peyer's patches) are where these mature lymphocytes encounter antigens and initiate an immune response.
6. Can Peyer's patches become enlarged or cause health problems?
Yes, Peyer's patches can become enlarged, a condition known as lymphoid hyperplasia. This is often a normal reaction to infection (e.g., a stomach virus) as the immune system activates. However, in some cases, particularly in children, excessively swollen Peyer's patches can act as a lead point for intussusception (where one part of the intestine slides into another). Furthermore, they can serve as a portal of entry for certain pathogens, like prions which cause neurodegenerative diseases.
7. How do Peyer's patches differ from other lymphoid tissues like the tonsils or appendix?
While all are part of the body's Mucosa-Associated Lymphoid Tissue (MALT), they differ in location and primary area of surveillance.
- Peyer's Patches: Located in the small intestine, they specifically monitor pathogens in ingested food passing through the ileum.
- Tonsils: Located in the pharynx, they form a protective ring to guard against pathogens entering through the nose and mouth.
- Appendix: Attached to the large intestine, it contains significant lymphoid tissue and is thought to function as a storage site for beneficial gut bacteria, in addition to its immune role.
