Peyer patch

Peyer patch

      any of the nodules of lymphatic cells that aggregate to form bundles or patches and occur usually only in the lowest portion (ileum) of the small intestine; they are named for the 17th-century Swiss anatomist Hans Conrad Peyer.

      Peyer patches are round or oval and are located in the mucous membrane lining of the intestine. They can be seen by the naked eye as elongated thickened areas, and their surface is free of the projections (villi) and depressions (Lieberkühn glands) that characterize the intestinal wall. Usually there are only 30 to 40 patches in each individual. In young adults they may be more numerous, and as a person ages they tend to become less prominent. Their full function is not known, but they do play a role in immunologic response and contain B and T cells similar to those found in peripheral lymph nodes (lymph node).

      In typhoid fever, these patches may become sites of inflammation, in which case they may develop into ulcerations, hemorrhages, or perforations.

* * *


Universalium. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • Peyer's patch — Pey·er s patch pī ərz n any of numerous large oval patches of closely aggregated nodules of lymphoid tissue in the walls of the small intestine esp. in the ileum that partially or entirely disappear in advanced life and in typhoid fever become… …   Medical dictionary

  • patch — 1. A small circumscribed area differing in color or structure from the surrounding surface. 2. In dermatology, a flat area greater than 1.0 cm in diameter. 3. An intermediate stage in the formation of a cap …   Medical dictionary

  • Peyer's patch — noun any of several lymph nodes in the walls of the intestines near the junction of the ileum and colon • Syn: ↑Peter s gland • Hypernyms: ↑lymph node, ↑lymph gland, ↑node * * * ˈpī(ə)rz noun also …   Useful english dictionary

  • peyer's gland — noun see peyer s patch …   Useful english dictionary

  • Peyer's patches — Lymphoid organs located in the submucosal tissue of the mammalian gut containing very high proportions of IgA secreting precursor cells. The patches have B and T dependent regions and germinal centres. A specialized epithelium lies between the… …   Dictionary of molecular biology

  • Craig Peyer — Craig A. Peyer California Highway Patrol Place of birth California, USA Service branch United States Years of service 1980 1986 …   Wikipedia

  • digestive system, human — Introduction  the system used in the human body for the process of digestion. The human digestive system consists primarily of the digestive tract (alimentary canal), or the series of structures and organs through which food and liquids pass… …   Universalium

  • lymphatic system — Anat., Zool. the system by which lymph is returned from the cells to the blood and by which white blood cells are produced in response to inflammation or presence of antigens; in mammals, the system includes the lymph glands, vessels and sinuses… …   Universalium

  • ileum — ileal, adj. /il ee euhm/, n., pl. ilea /il ee euh/. 1. Anat. the third and lowest division of the small intestine, extending from the jejunum to the cecum. See diag. under intestine. 2. Zool. the anterior portion of the hindgut of an insect or… …   Universalium

  • lymphoid tissue — Cells, tissues, and organs composing the immune system, including the bone marrow, thymus, spleen, and lymph nodes. The most highly organized components are the thymus and lymph nodes, and the least organized are the cells that wander in the… …   Universalium

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”