Alpha particle: A tiny mass of material composed of two protons and two neutrons.
Alpha particles do not travel very far from their radioactive source. They cannot pass through a piece of paper, clothes or even the layer of dead cells which normally protects the skin. Because alpha particles cannot penetrate human skin they are not considered an “external exposure hazard.” This means that if the alpha particles stay outside the human body they cannot harm it. However, alpha particle sources located within the body may pose an “internal” health hazard if they are present in great enough quantities.
For instance, the risk from indoor radon gas is due to inhaled alpha particle sources which irradiate lung tissue.
Alpha rays are streams of alpha particles.
- Alpha thalassemia
heme and globin. Globin is made up of 4 polypeptide chains. In normal adult hemoglobin (Hb A), the predominant type of hemoglobin after the first year of life, 2 of the globin polypeptide chains are identical to one another and are designated the alpha chains. The other 2 chains are also identical to one another […]
- Alpha-1 antitrypsin deficiency
An inherited disorder characterized by a lack of the alpha-1 antitrypsin protease inhibitor. Alpha-1 antitrypsin deficiency leads to damage of various organs, especially the lung and liver. Symptoms may become apparent at a very early age or anytime later, manifesting as shortness of breath due to emphysema or as liver symptoms such as jaundice, fatigue, […]
Alpha-ethltryptamine: An illicit hallucinogenic drug related to tryptamine. Street names for alpha-ethyltryptamine include: Alpha-ET; ET; Love pearls; Trip (also refers to LSD). Many agents in the class of tryptamines are hallucinogenic substances that exist naturally in some plants, fungi, and animals, but also can be produced synthetically. These hallucinogens have been placed in Schedule I […]
- Alpha-fetoprotein (AFP)
Alpha-fetoprotein (AFP): AFP is a plasma protein that is normally produced by the fetus. It serves as the basis for some valuable tests. AFP is manufactured principally in the fetus’s liver and gastrointestinal (GI) tract besides the yolk sac, a structure temporarily present during embryonic development. The AFP level is typically high in the fetus’s […]
- Alpha-glucosidase inhibitor
Alpha-glucosidase inhibitor: A class of oral medications for type 2 diabetes that decrease the absorption of carbohydrates from the intestine, resulting in a slower and lower rise in blood glucose throughout the day, especially right after meals. Before carbohydrates are absorbed from food, they must be broken down into smaller sugar particles like glucose by […]