| CN | caudate nucleus; cellulose nitrate; charge nurse; child nutrition; chloroacetophenone; clinical nurs... |
|---|---|
| LCN | lateral cervical nucleus; left caudate nucleus; lipocalin |
| RN | radionuclide; red nucleus; Registered Nurse; registry number; residual nitrogen; reticular nucleus |
| STN | streptozocin; subthalamic nucleus; supratrochlear nucleus |
| TN | talonavicular; tarsonavicular; team nursing; temperature normal; tenascin; trigeminal nucleus; total... |
| principal artery of thumb | <anatomy, artery> Origin, radial (deep palmar (arterial) arch); distribution, palmar surface and sides of thumb; anastomoses, arteries on dorsum of thumb. Synonym: arteria princeps pollicis, chief artery of thumb, princeps pollicis, principal artery of thumb. (05 Mar 2000) |
|---|---|
| principal focus | The real or virtual meeting point of rays passing into a lens parallel to its axis. (05 Mar 2000) |
| principal investigator | The head researcher responsi for organising and overseeing a clinical trial (09 Oct 1997) |
| principal islets | Separate globular aggregates made up mostly of endocrine pancreatic tissue; present in some fishes and snakes. (05 Mar 2000) |
| principal optic axis | A line passing through the centre of the lens of a refracting system at right angles to its surface. (05 Mar 2000) |
| principal plane | <microscopy> A plane normal to the principal axis of a lens, passing through a principal point. In geometrical construction of ray diagrams through a perfect lens, the single plane that can be considered (disregarding the refraction of the rays at each optical interface) to convert paraxial rays into rays converging onto the rear focal point. For thin symmetrical lenses, there is one principal plane that bisects the lens. For thick or complex lenses, there is a principal plane for the paraxial ray to the left, and another for the paraxial ray to the right, of the lens. (05 Aug 1998) |
| principal point | <microscopy> Mutually conjugate points lying on the lens axis and producing a magnification of one. Object and image distance as well as focal length are calculated (measured) from these points. (05 Aug 1998) |
| focus, principal | <physics> The point at which a lens focuses an axial object point. Synonymous with focal point. (05 Aug 1998) |
| abducens nucleus | Nucleus of abducent nervenucleus abducentis, a group of motor neurons in the lower part of the pons, innervating the lateral rectus muscle of the eye; unique among motor cranial nerve nuclei in that it consists of two distinct populations of neurons: neurons that give rise to fibres forming the abducens nerve root and those internuclear neurons whose processes cross the midline, ascend in the opposite medial longitudinal fasciculus, and terminate upon specific oculomotor neurons; considered a primary centre for mechanisms controlling conjugate horizontal gaze. Synonym: nucleus nervi abducentis. (05 Mar 2000) |
| accessory cuneate nucleus | A cell group lateral to the cuneate nucleus which receives posterior-root fibres corresponding to the proprioceptive innervation of the arm and hand; it projects to the cerebellum by way of the cuneocerebellar tract, and can be considered the upper-extremity equivalent of the thoracic nucleus. Synonym: nucleus cuneatus accessorius, external cuneate nucleus, lateral cuneate nucleus, Monakow's nucleus. (05 Mar 2000) |
| almond nucleus | Almond-shaped group of basal nuclei anterior to the inferior horn of the lateral ventricle of the brain, within the temporal lobe. The amygdala is part of the limbic system. (12 Dec 1998) |
| ambiguous nucleus | A very slender, longitudinal column of motor neurons in the ventrolateral medulla oblongata; its efferent fibres leave with the vagus and glossopharyngeal nerve and innervate the striated muscle fibres of the pharynx (including the musculus levator veli palatini) and the vocal cord muscles of the larynx. Synonym: ambiguous nucleus. (05 Mar 2000) |
| amygdaloid nucleus | Almond-shaped group of basal nuclei anterior to the inferior horn of the lateral ventricle of the brain, within the temporal lobe. The amygdala is part of the limbic system. (12 Dec 1998) |
| anterior extremity of caudate nucleus | The head or anterior extremity of the caudate nucleus projecting into the anterior horn of the lateral ventricle. Synonym: caput nuclei caudati, anterior extremity of caudate nucleus. (05 Mar 2000) |
| anterodorsal thalamic nucleus | anterodorsal thalamic nucleus |