A
Acidosis |
Alactasia Lack of the enzyme lactase which is needed to digest the milk sugar lactose. |
AAlbumin The main protein in human blood and the key to the regulation of the osmotic pressure of blood. Chemically, albumin is soluble in water, precipitated by acid, and coagulated by heat. |
Alkalosis |
Allergen A substance that is foreign to the body and can cause an allergic reaction in certain people. For examples, pollen, dander, mold. |
Allergy A misguided reaction to foreign substances by the immune system, the body system of defense against foreign invaders, particularly pathogens (the agents of infection). The allergic reaction is misguided in that these foreign substances are usually harmless. The substances that trigger allergy are called allergen. |
Anaphylactic shock A widespread and very serious allergic reaction. Symptoms include dizziness, loss of consciousness, labored breathing, swelling of the tongue and breathing tubes, blueness of the skin, low blood pressure, heart failure, and death. Immediate emergency treatment is required. |
Antibody An immunoglobulin, a specialized immune protein, produced because of the introduction of an antigen into the body, and which possesses the remarkable ability to combine with the very antigen that triggered its production. The production of antibodies is a major function of the immune system and is carried out by a type of white blood cell called a B cell (B lymphocyte). Antibodies can be triggered by and directed at foreign proteins, microorganisms, or toxins. Some antibodies are autoantibodies and home in against our own tissues. |
Anus The opening of the rectum to the outside of the body. |
Appendix A small outpouching from the beginning of the large intestine (the ascending colon). |
Autoantibody An antibody directed against the patient's own body tissue. |
Autoimmunity |
Autosomal recessive |