|
|
|||
|
Hypersensitivity Question
Hi Im studying right now Pathology and I have a big doubt
When it come to Hyersensitivity type II I found included Myasthenia and Graves disease but....Ive been doing some researching and found out there is V type of Hypersensitivity Stimulatory where it sould be included myasthenia and graves.... Can someone help me....pleeez!!! |
|
||||
|
Stay with the traditional 4, it will not hurt to know that extra one exist, but just stay with the 4 main one.
A little review for the other people about Hypersensitivity Type 1 Something that normally wold not give you a problem, like dust,pet dander, trees, etc. Your body for some reason gets a little crazy and says NO I DO NOT LIKE THIS DUDE. So the second time you are in contact you create an allergic reaction. Lets say you are In party and you see a lady that everyone think is the best, then for some reason you do not like her. Next time when you see the lady your Buddy IgE says to you dude thats the chick you do not like and you just burst into a living hell ![]() That guy has serious issues ![]() Type 2 You create antibodies that go crazy on you, and they start attacking your own cells .Type 3 You have and org with 3 people Antigen Antibody Compleme They are together and they just go and sit in a specific area, then someone passing by, looks at them and say hey hey whats going on there and start destroying the tissue involve. Type 4 Today is Saturday And I'm kind of lazy here is a link in case you guys did not understood what I try to explain. Hypersensitivity PS please correct anything you see wrong in my explications, I do not mind better for you and the other people, and serve you as a little review.
__________________
Moderator: USMLE Step 1 Forums, USMLE Step 2 Forums,USMLE Step 3 Forums. Last edited by IMG SURVIVOR : 03-22-2008 at 05:50 PM. |
|
|||
|
I tnink I can manage that !
![]() thank u ...but its kind difficult to remember graves and myasthenia in Type II. I found some q? that may help too... A 26-year-old systems analyst presents for evaluation of a bee sting allergy. He describes an episode in which he E. TH1 CD4+ lymphocytewas stung on the forearm by a bee and, within 5 minutes, experienced pruritus, urticaria, and mild wheezing. The effector cell in this type of hypersensitivity is a(n) A. eosinophil B. mast cell C. megakaryocyte D. neutrophil Explanation: dermatitis involving exposure to poison ivy or poison oak.The correct answer is B. This patient is experiencing the early phase of type I hypersensitivity, characterized by pruritus and watery discharge from the nose, bronchospasm, mucus secretion in the airways, and a wheal-and-flare response with pruritus in the skin. The mechanism of hypersensitivity involves prior sensitization of a population of TH2 cells that produced cytokines, including interleukin-4. The interleukin-4 causes B cells to switch their heavy chain class from IgM to IgE. The IgE molecules then attach to mast cells or basophils. With subsequent antigen (allergen) challenge, the mast cells degranulate and release mediators, including histamine, which produces the anaphylactic response. Eosinophils (choice A) are involved in type I hypersensitivity reactions as well as type II antibody-dependent cell cytotoxicity reactions directed against parasites. Eosinophils enter the area of the reaction due to the release of eosinophil chemotactic factor (eotaxin) and the beta-chemokine RANTES released from TH2 CD4+ cells and mast cells. Eosinophils are recruited into the tissues as part of the late-phase reaction of type I hypersensitivity. Their survival in tissue is dependent upon IL-3, IL-5, and granulocyte-monocyte colony stimulating factor (GM-CSF) released from TH2 cells. Megakaryocytes (choice C) are bone marrow cells that produces platelets. They are not involved in type I hypersensitivity. Neutrophils (choice D) are not a cell type that is key to the development of type I hypersensitivity. TH1 CD 4+ lymphocytes (choice E) are associated with delayed type hypersensitivity reactions such as contact A Mexican immigrant presents with a 3-month history of weight loss, night sweats, a productive cough with hypersensitivity.blood-tinged sputum, anorexia, general malaise, and a low grade fever. A PPD skin test shows > 10 mm of induration. If the area of induration were biopsied, which of the following type of reactive cells would be found? A. B lymphocyte B. Eosinophil C. Mast cell D. Neutrophil E. T lymphocyte Explanation: The correct answer is E. The CD4+ population of T lymphocytes, specifically TH1 cells, are responsible for the delayed hypersensitivity reaction seen with a skin test in a previously sensitized patient. The clinical pattern in the test question is classic for reactivation or adult-type tuberculosis. One of the risk factors to consider in evaluating a patient for tuberculosis is a foreign-born patient who has recently immigrated to the U.S. A 10 mm reaction on a skin test is considered positive if the person is in a high-incidence group (foreign born, medically underserved, low-income population, or resident of a long-term care facility). B lymphocytes (choice A) are involved in humoral immune reactions. Antibody production is not a feature of tuberculosis hypersensitivity. Eosinophils (choice B) are important in type I hypersensitivity reactions and in immune mediated responses to parasitic infections (ADCC). They are not associated with tuberculosis hypersensitivity. Mast cells (choice C) are tissue cells which are involved in type I hypersensitivity reactions. They have surface receptors for the Fc fragment of the IgE molecule. Neutrophils(choice D) are associated with acute inflammatory reactions. They are considered a "non-specific" cell in that they do not interact with an antigen. The neutrophil is not a classic cell type seen in tuberculosis |
![]() |
| Thread Tools | |
| Display Modes | |
|
|
|
|
||||
| Thread | Thread Starter | Forum | Replies | Last Post |
| chat transcript - physiology part 1 (muscle, cardiac, endo) | Anonymous | USMLE Step 1 Forum | 1 | 01-24-2006 05:23 AM |
| 130 Immunology questions and answers | Anonymous | USMLE Step 1 Forum | 3 | 07-04-2005 08:14 PM |
| Chat transcript - Micro (bacteria, fungi) | Anonymous | USMLE Step 1 Forum | 0 | 08-12-2004 12:26 AM |
| Moonlighting vs. Night Float ? | wowmd | Moonlighting Forum | 14 | 07-30-2004 12:24 PM |
| chat transcript - immunology | Anonymous | USMLE Step 1 Forum | 0 | 06-17-2004 12:17 AM |
International Foreign and Caribbean medical schools,
ValueMD provides information on medical education from premed to residency