Anaerobic: Not requiring oxygen. Anaerobic bacteria, for example, do not require oxygen to grow.
ANA: Antinuclear antibody, an unusual antibody directed against structures within the nucleus of the cell. ANAs are found in patients whose immune system is predisposed to cause inflammation against their own body tissues. Antibodies that are directed against one’s own tissues are referred to as autoantibodies. The propensity for the immune system to work against […]
An-: Prefix very much employed in medicine and all of the health sciences, indicating “not, without, or -less.” For example, the prefix “an” figures into these words: anemia (without blood), anophthalmia (no eye), anotia (no ear), anoxia (no oxygen). The “an-” usually becomes “a-” before a consonant as, for example, in alexia (not read), aphagia […]
Anion: A negatively charged ion. Pronounced an-I-on. An anion is as opposed to a cation, which is a positively charged ion.
- Anion gap
Anion gap: A measurement of the interval between the sum of “routinely measured” cations minus the sum of the “routinely measured” anions in the blood. The anion gap = (Na+ + K+) – (Cl- + HCO3-) where Na- is sodium, K+ is potassium, Cl- is chloride, and HCO3- is bicarbonate. The anion gap can be […]
Aniso-: Unequal, unlike, or dissimilar. As in anisocoria, anisocytosis, and anisometropia. From the Greek anisos meaning unequal, from an-, not, + isos, equal. The opposite of aniso- is iso-.