This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: 1 Allergy , from allo , other; and ergon , work: body working in response to external factors. Term coined by the Austrian pediatrician, Clemens Pirquet von Casenatico. Allergic reaction Set of bodily changes occurring when some people are exposed to agents in the environment to which they have become sensitive. Allergies Runny nose, flushing, itching, sneezing, fever. Chem 004 - Spring 2006 Blackboard: http://blackboard.gwu.edu Office Hours: MW 3:10-3:55 PM, 1957 E street, room 213, or by appointment Antigens and allergens Most particles, dust, pollen, etc., are filtered by the hair and mucus in the nose and airways but, when present in a large number, some may pass into the lungs and even enter the bloodstream.- _____________ or _________ , detect foreign unfamiliar molecules, called _______ . Antigens that trigger allergic reactions are known as __________ .- White blood cells multiply (clones). Clones recognize the same antigen. This process takes from a few hours to several days.- Some of these clones cells become ‘ ___________ ’ in the lymph glands.- When the person is exposed to the same antigen on a later occasion , it will be detected by memory cells in minutes, and more clones are formed. This process is known as ‘ _________________ ’ . Allergies An allergic response involves foreign particles such as pollen which have complex molecules on their surface (__________) These molecules trigger white blood cells to produce ____________... …and to multiply... ‘ Memory ’ cells generate a huge number of antibodies when they meet the same antigen again in the future. On re-exposure, the antibodies attach to the foreign molecules The interaction of antibody and foreign antigen... What causes an allergic reaction? Attracts white blood cells which engulf the invaders and digest them Triggers a cascade of reactions in blood which leads to white blood cells and mast cells releasing... White blood cells also release _________: ___________ and leukotrienes, causing itching, wheezing, asthma and runny nose Large, complex molecules (___________) produced by white blood cells that bind very tightly to their targets (___________). They are produced in vertebrates as a defense against infection. Antibodies Antibodies remain in the bloodstream keeping a lookout for any reappearance of the foreign antigen. The antigen-antibody complex triggers the release of chemicals call _____________ , by white blood cells and ‘ mast ’ cells. 2 Mediators Histamine, leukotrienes, interleukins, and others. • Relax blood vessels and activate sensory nerves in the skin • Increase secretion of mucus by gland cells in the airways and contract the muscle in the airways • Affect receptors in brain cells N N H NH 2 Histamine • Irritate membranes lining the nose, dilate blood vessels in the nose, and increase leakiness of blood vessels....
View Full Document
- Spring '06
- Allergy, H2 H2