| extrapyramidal motor system | Literally: all of the brain structures affecting bodily (somatic) movement, excluding the motor neurons, the motor cortex, and the pyramidal (corticobulbar and corticospinal) tract. Despite its very wide literal connotation, the term is commonly used to denote in particular the striate body (basal ganglia), its associated structures (substantia nigra; subthalamic nucleus), and its descending connections with the midbrain. (05 Mar 2000) |
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| extrapyramidal motor system disease | A general term for a number of disorders caused by abnormalities of the basal ganglia or certain brain stem or thalamic nuclei; characterised by motor deficits, loss of postural reflexes, bradykinesia, tremor, rigidity, and various involuntary movements. Synonym: extrapyramidal motor system disease. (05 Mar 2000) |
| extrapyramidal | Outside of the pyramidal tracts. (18 Nov 1997) |
| extrapyramidal cerebral palsy | <neurology> A derangement marked by ceaseless occurrence of slow, sinuous, writhing movements, especially severe in the hands and performed involuntarily, it may occur after hemiplegia and is then known as posthemiplegic chorea. Synonym: mobile spasm. Origin: Gr. Athetos = not fixed (13 Nov 1997) |
| extrapyramidal disease | A general term for a number of disorders caused by abnormalities of the basal ganglia or certain brain stem or thalamic nuclei; characterised by motor deficits, loss of postural reflexes, bradykinesia, tremor, rigidity, and various involuntary movements. Synonym: extrapyramidal motor system disease. (05 Mar 2000) |
| extrapyramidal dyskinesias | Abnormal involuntary movements attributed to pathological states of one or more parts of the striate body and characterised by insuppressible, stereotyped, automatic movements that cease only during sleep; e.g., Parkinson's disease; chorea; athetosis; hemiballism. (05 Mar 2000) |
| extrapyramidal effect | A combination of neurologic effects which includes tremors, chorea, athetosis and dystonia. A common side effect of neuroleptic agents (phenothiazines). Other medications known to cause these reactions include haloperidol, molindone, perphenazine & amitriptyline, loxapine, pimozide and rarely, benzodiazepines. (27 Sep 1997) |
| extrapyramidal syndrome | <syndrome> Abnormalities of movement related to injury of motor pathways other than the pyramidal tract. (05 Mar 2000) |
| absolute system of units | A system based on absolute units accepted as being fundamental (length, mass, time) and from which other units (force, energy or work, power) are derived; such system's in common use are the foot-pound-second, centimeter-gram-second, and meter-kilogram-second system's. (05 Mar 2000) |
| absorbent system | <anatomy> The tissues and organs (including the bone marrow, spleen, thymus and lymph nodes) that produce and store cells that fight infection and the network of vessels that carry lymph. (12 May 1997) |
| alimentary system | The organs that are responsible for getting food into and out of the body and for making use of food to keep the body healthy. These include the mouth, oesophagus, stomach, liver, gallbladder, pancreas, small intestine, colon, and rectum. (12 Dec 1998) |
| anterolateral system | A composite bundle of fibres, located in the ventrolateral part of the lateral funiculus, containing spinothalamic, spinohypothalamic, spinoreticular, and spinomesencephalic (spinotectal, spinal to periaqueductal grey, etc.) fibres; occupies the combined areas of the spinal white matter historically divided into anterior and lateral spinothalamic tracts; located in white matter ventral to the denticulate ligament, hence the anatomical basis for the anterolateral cordotomy; concerned with the transmission of nociceptive and thermal information and with crude (nondiscriminative) touch. (05 Mar 2000) |
| anti-allergic and respiratory system agents | A collective term for drugs used to treat allergic reactions as well as those drugs that produce an effect on the respiratory system. (12 Dec 1998) |
| arch-loop-whorl system | See: Galton's system of classification of fingerprints. (05 Mar 2000) |
| association system | Groups or tracts of nerve fibres interconnecting different regions of one and the same major subdivision of the central nervous system, such as the various areas of the cerebral cortex or the various segments of the spinal cord. (05 Mar 2000) |