( ĭgwä'nə ), name for several large lizards of the family Iguanidae, found in tropical America and the Galapagos. The common iguana (Iguana iguana) is
The adaptable system of body defences centres on specialized white blood cells called lymphocytes. These respond to invasion by varied microorganisms.
The body's defence against foreign substances such as bacteria, viruses and parasites. Immunity also protects against drugs, toxins and cancer cells.
Process of conferring immunity or resistance to an infectious disease by artificial methods, usually by the administration of a vaccine . Immunization
In the late 18th century Dr. Edward Jenner stumbled upon the notion of the immune system following his discovery that cowpox protected him against a
A contagious skin disease, more common in children, caused usually by Staphylococcus aureus and less often by Streptococcus pyogenes . The itching
( im'pətəns ), inhibited sexual excitement in a man during sexual activity that, despite an unaffected desire for sex, results in inability to attain
stage of human development lasting from birth to approximately two years of age. The hallmarks of infancy are physical growth, motor development,
blockage of blood circulation to a localized area or organ of the body resulting in tissue death. Infarctions commonly occur in the spleen , kidney,
inability to conceive or carry a child to delivery. The term is usually limited to situations where the couple has had intercourse regularly for one