1. REVIEW: Contrast B and T cells or lympocytes with respect to origin, differentiation,and function. B-cells-___________ __________________ __________________ __________________ __________________ _____________ T-cells-___________ _________________ __________________ ________________

2. IMMUNE DISORDERS Consequence of malfunctioning immune system TYPES: Allergies: abnormal sensitivity to antigens in environment Autoimmune Disorders: when immune system turns against the body’s own molecules Immunodeficiency Diseases: when body lacks one or more components of immune system

3. How Allergies Develop Develop in two stages: 1. First exposure to allergen causes sensitization 2. Subsequent exposures to same allergen produce allergy symptoms

4. The Details….. 1.Allergen (pollen grain) enters blood stream. 2,B cells make antibodies 3.Antibodies attach to mast cell. 4.Allergen (pollen grain) binds to antibodies on mast cell. 5.Histamine is released, causing allergy symptoms. Because allergens usually enter through the nose and throat, symptoms are most prominent there. Spores

5. Anaphylactic shock- sudden release of inflammatory chemicals in people who are extremely sensitive to certain allergens, like: -bee stings -peanuts -shellfish What happens? Blood vessels dilate abruptly, causing a fatal drop in blood pressure, a condition called shock. Anaphylactic shock can be counteracted with injections of epinephrine.