| openings of pulmonary veins | The orifices of the pulmonary veins, usually two on each side, in the wall of the left atrium. Synonym: ostia venarum pulmonalium. (05 Mar 2000) |
|---|---|
| urethral openings | See: external urethral orifice, internal urethral orifice. (05 Mar 2000) |
| attention | Focusing on certain aspects of current experience to the exclusion of others. It is the act of heeding or taking notice or concentrating. (12 Dec 1998) |
| attention deficit disorder | An inability to control behaviour due to difficulty in processing neural stimuli. (12 Dec 1998) |
| attention deficit disorder with hyperactivity | A behaviour disorder originating in childhood in which the essential features are signs of developmentally inappropriate inattention, impulsivity, and hyperactivity. Although most individuals have symptoms of both inattention and hyperactivity-impulsivity, one or the other pattern may be predominant. The disorder is more frequent in males than females. Onset is in childhood. Symptoms often attenuate during late adolescence although a minority experience the full complement of symptoms into mid-adulthood. (12 Dec 1998) |
| attention deficit hyperactivity disorder | <psychiatry> A condition seen in children where there is increased motor activity in association with poor attention span. Often treated with amphetamine medications. (27 Sep 1997) |
| artificial | Made by art, not natural or pathological. Origin: L. Ars = art, facere = to make (18 Nov 1997) |
| artificial active immunity | See: acquired immunity. (05 Mar 2000) |
| artificial anatomy | The manufacture of models of anatomic structures, or the study of anatomy from such models. (05 Mar 2000) |
| artificial ankylosis | <orthopaedics> The surgical immobilisation of a joint (joint fusion). (27 Sep 1997) |
| artificial anus | An opening into the bowel, usually in the right or left flank, as a result of a colostomy. (05 Mar 2000) |
| artificial Carlsbad salt | A mixture of potassium sulfate, sodium chloride, sodium bicarbonate, and dried sodium sulfate; a laxative. (05 Mar 2000) |
| artificial classification | <zoology> Classification based on convenient or conspicuous diagnostic characters without attention to characters indicating relationship, often a classification based on a single arbitrarily chosen character, rather than an evaluation of the totality of characters. (09 Jan 1998) |
| artificial crown | A fixed restoration of the major part of the entire coronal part of a natural tooth; usually of gold, porcelain, or acrylic resin. (05 Mar 2000) |
| artificial dentition | <dentistry> A synthetic replacement for all of your teeth in either your upper or your lower jaw. (08 Jan 1998) |