Chapter 35.4

1. Chapter 35.4 Nick Lemr Alex Garcia Aman Patel Dmitri Duggan Matt Foley

2. Allergic Reactions • When your body is hypersensitive to things that would normally be harmless e.g. peanuts and comes in contact with these substances, an allergic reaction occurs • The body’s response to these allergens, often include some degree of tissue damage • Most allergic reactions are merely unpleasant, but some can be fatal

3. Immediate Allergic Response • Can occur within seconds of coming in contact with an antigen • Responses are caused by IgE Antibodies that are attached to the plasma membrane of mass cells in tissues and basophils in blood • IgE cells release histamines and other substances that cause allergic symptons • Ex. When someone who’s allergic to pollen comes in contact with pollen, IgE cells release histamines that stimulate the body’s mucus membranes, causing runny nose and watery eyes symptomatic of hay fever

4. Immediate Allergic Response cont. • Anaphalyctic shock occurs when an allergen enters the blood stream • Commonly caused by bee stings and penicillin shots • Characterized by spontaneous and potentially fatal drop in blood pressure due to increased permeability caused by histamines

5. Delayed Allergic Responses • Initiated by memory T cells wherever the allergen comes in contact with the body • Regulated by cytokines secreted by T cells and macrophages • Can take several hours or even a day • Common example: Poison ivy

6. What is Sample Rejection? • Sample rejection is where a living thing receives another living thing’s tissue or other body part has been donated for medical use. And when the recipient receives the said donated tissue or other body part, the immune system of the recipient rejects the sample and tries to destroy it.

7. But whyyyyyyy… • Especially the immune system detects a foreign substance inside the body, it seeks to destroy it at all costs. And like the little microscopic war machine your body is, it does the job much to well, destroying the donated body part. Unfortunately if you need a kidney and your body wont have any of it, that could be problematic.

8. What could I do? • You personally cannot do anything. In a sense, you are the problem. However, the medical staff at your hospital can help you greatly. After said transplant, the medical staff will most likely give you Immunosuppressant Drugs, to obviously suppress your immune system to prevent the rejection of the transplanted body part, so that the body will get used to it and, after a time, consider it as a part of your body.

9. Tissue Rejection • Certain organs such as the skin, the heart, and the kidneys could be transplanted easily from one person to another if the body did not attempt to reject them. • Rejection occurs because antibodies and cytotoxic T cells bring destruction of foreign tissue in the body. When rejection occurs the immune system is correctly distinguishing between self and nonself. • Organ rejection can be controlled by carefully selecting the organ to be transplanted and administering immunosuppressive drugs. • Two well known immunosuppressive drugs are cyclosporine and tricrolimus, both act by inhibiting the response of T cells to cytokines. • It is the best if the transplanted organs as the same antigens as those of recipient, because cytotoxic T cells recognize foreign antigens. • Xenotransplantation is the transplantation of animal tissues and organs in to human beings is another way to solve the problem of supply. The first animal-human heart transplant occurred in 1984 when a baboon heart was given to an infant, who unfortunately lived for a short time.

10. Autoimmune diseases • Autoimmune disease is where chronic inflammation is present and cytotoxic T cells and antibodies mistakenly attack the body's own cells. Only sometimes it sets in noticeable infection otherwise they probably start after and inflammatory response. • In this disease myasthenia gravis, your neuromuscular junction does not work properly, and muscles gets weak. • There are lot of autoimmune illnesses you could get like multiple sclerosis, rheumatoid arthritis, and type 1 diabetes. As yet they still found no cure for autoimmune diseases, but they can be controlled with medications.

11. What about Blood? • And Different blood types cannot be compatable with each other because of the anitbodies inside your body. For Example. Blood type B has a Anti-A antibody. Which means it will reject the A blood type. While Blood type AB has no anti-blood antibodies, so it can accept all bloodtypes.

12. Agglutination • Clumping of red blood cells • Stops circulation in smaller blood vessels • Leads to organ damage

13. RH System • 85% of the population is RH positive • RH is an antigen • RH-negative individuals usually lack antibodies to RH, but may develop them • If this occurs during a pregnancy, with the child being RH-positive due to the father, the mother may develop anitbodies • In latter pregnancies, if the child is RH-positive, the mother’s antibodies may attack the red blood cells • This is hemolytic disease (HDN) and requires a blood transfusion • Can be prevented by shots that prevent the mother from producing the antibodies by limiting the contact of the child’s blood cells