Peyer's patches
(noun)
Patches of lymphoid tissue or lymphoid nodules on the walls of the ileum in the small intestine.
Examples of Peyer's patches in the following topics:
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Histology of the Small Intestine
- The jejunum and ileum do not have Brunner's glands in the submucosa, while the ileum has Peyer's patches in the mucosa, but the duodenum and jejunum do not.
- Peyer's patches are organized lymph nodules.
- Peyer's patches function as the immune surveillance system of the intestinal lumen and facilitate the generation of the immune response within the mucosa.
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Lymphoid Tissue
- It is found mainly in the lymph nodes, but also in the lymphoid follicles in tonsils, Peyer's patches, spleen, adenoids, skin, and other areas associated with the mucosa-associated lymphoid tissue (MALT).
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Maturation of B Cells
- After reaching the IgM+ immature stage in the bone marrow, these immature B cells migrate to secondary lymphoid tissues (such as the spleen, lymph nodes, Peyer's patches, etc.) where they are called transitional B cells, and some of these cells differentiate into mature B lymphocytes.
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Transdermal Drug Administration
- A transdermal patch is a medicated adhesive patch that is placed on the skin to deliver a specific dose of medication through the skin and into the bloodstream.
- Vapor patch: In this type of patch, the adhesive layer not only serves to adhere the various layers together, but also to release vapor.
- These patches administered scopolamine for motion sickness.
- The highest-selling transdermal patch in the United States is the nicotine patch, which releases nicotine in controlled doses to help with cessation of tobacco smoking.
- A 21mg dose Nicoderm CQ patch applied to the left arm.
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Vitiligo
- The most notable symptom of vitiligo is depigmentation of patches of skin that occurs on the extremities.
- Although patches are initially small, they often enlarge and change shape.
- In mild cases, vitiligo patches can be hidden with makeup or other cosmetic camouflage solutions.
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Alopecia
- Typical first symptoms of AA are small bald patches.
- These patches can take many shapes, but are most usually round or oval.
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Excretion and Absorption
- The most common mechanism of administration through the skin is the use of ointments or an adhesive patch, such as the nicotine patch or iontophoresis.
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Aspirin and Thrombolytic Agents
- Aspirin also has an antiplatelet effect, inhibiting the production of thromboxane, which otherwise binds platelet molecules together creating a patch over damaged walls of blood vessels.
- The platelet patch can become too large and block blood flow both locally and downstream.
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Allergies
- A microscopic amount of an allergen (for example, tree pollen) is introduced to a patient's skin by means of either a prick test, which employs a needle or pin to break the skin's surface, or a patch test, where a patch containing the allergen is applied to the skin.
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Skin Color as a Diagnostic Clue
- Although it can affect anyone, it is particularly common in women, especially pregnant women and those who are on oral or patch contraceptives, or hormone replacement therapy (HRT) medications.
- Its symptoms are dark, irregular, well-demarcated, hyperpigmented patches commonly found on the upper cheek, nose, lips, upper lip, and forehead.
- These patches often develop gradually over time.