Aetiology: The study of the causes. For example, of a disorder.
The word “aetiology” is mainly used in medicine, where it is the science that deals with the causes or origin of disease, the factors which produce or predispose toward a certain disease or disorder.
Today in medicine one hears (or reads) that “the aetiology is unknown.” Translation — we don’t know the cause.
Aetiology is the preferred spelling in some countries, including the UK, whereas “etiology” without an “a” has taken over in the US. The word “aetiology” comes from the Greek “aitia”, cause + “logos”, discourse.
Affect: The emotional tone a person expresses. A person’s affect may be appropriate or inappropriate to the situation. One type of inappropriate affect is a flat affect or blunted affect, a common feature of schizophrenia.
- Affective disorder, seasonal (SAD)
Affective disorder, seasonal (SAD): Depression that tends to occur (and recur) as the days grow shorter in the fall and winter. It is believed that affected persons react adversely to the decreasing amounts of light and the colder temperatures as the fall and winter progress. Seasonal affective disorder has not been recognized very long as […]
Afferent: Carrying toward. A vein is an afferent vessel because it carries blood from the body toward the heart. The opposite of afferent is efferent.
- Afferent nerve
Afferent nerve: A nerve that carries impulses toward the central nervous system.
- Afferent vessel
Afferent vessel: A vessel that carries blood toward the heart. A vein or venule.