The immunologic state induced in a susceptible individual by an allergen; characterized by a marked change in the subjects reactivity (e.g., hay fever – Type I hypersensitivity; reaction to the metal nickel – Type IV hypersensitivity).
Letter: a
Pain due to a stimulus that does not normally provoke pain and can be either thermal or mechanical.
Includes the herpes simplex viruses 1 and 2, and varicella zoster virus (shingles), which establish themselves within the sensory ganglia after initial infection and remain dormant until reactivated by a trigger such as stress.
Alveolar dead space is caused by air contacting alveoli without blood flow in their adjacent pulmonary capillaries, i.e. ventilation without perfusion. As a result, no gas exchange can occur. Alveolar dead space is negligible in healthy individuals, but can increase dramatically in some lung diseases.
The tiny end ducts of the branching airways that fill the lungs. Each lung holds approximately 1.5 to 2 million of them. The tubules divide into two or three alveolar sacs at the distal end. They are formed from the confluence openings of several alveoli. Distal terminations of alveolar ducts are atria which then end in alveolar sacs.
Macrophages that reside in the alveoli of the lung, where they ingest foreign material including bacteria that have evaded clearance mechanisms in the proximal portion of the respiratory system. Along with neutrophils, macrophages are the major phagocytic cells of the immune system.
Abbreviation for Activated Clotting Time
Transformed immune cells that have achieved their full capacity to track down, acquire, and attack foreign threats. (e.g. activated macrophages, neutrophils, T-cells)
Immunity obtained during a persons life that provides the ability to produce white cells or antibodies to a specific disease causing agent and build immune-memory for rapid defense against future challenges by the same organism.
An individual who harbors an infectious organism and can spread it to others. The carrier does not become ill.