| bacterial outer membrane proteins | Proteins isolated from the outer membrane of bacteria. (12 Dec 1998) |
|---|---|
| outer membrane | The larger of the two membranes of a double membrane. (05 Mar 2000) |
| rod outer segment | <ophthalmology, physiology> Major photoreceptor cell of vertebrate retina (about 125 million in a human eye). Columnar cells (about 40m long, 1m diameter) having three distinct regions: a region adjacent to and synapsed with, the neural layer of the retina contains the nucleus and other cytoplasmic organelles, below this is the inner segment, rich in mitochondria, that is connected through a thin neck (in which is located a ciliary body) to the outer segment. The outer segment largely consists of a stack of discs membrane infoldings that are incompletely separated in cones) that are continually replenished near the inner segment and that are shed from the distal end and phagocytosed by the pigmented epithelium. The membranes of the discs are rich in rhodopsin, the pigment that absorbs light. (03 Jul 1999) |
| rod outer segments | The portion of the retinal rod cell between the inner segment and the pigment epithelium layer of the retina. (12 Dec 1998) |
| hair cells, outer | Mechanoreceptors in the organ of corti. In mammals the outer hair cells are arranged in three rows which are further from the modiolus than the single row of inner hair cells. The motile properties of the outer hair cells may contribute actively to tuning the sensitivity and frequency selectivity of the cochlea. (12 Dec 1998) |
| outer cone fibre | Located between the inner segment and the cell body. (05 Mar 2000) |
| outer malleolus | The process at the lateral side of the lower end of the fibula, forming the projection of the lateral part of the ankle; the lateral malleolus is more inferiorly placed then the medial malleolus. Synonym: malleolus lateralis, external malleolus, extramalleolus, outer malleolus. (05 Mar 2000) |
| outer table of skull | The outer compact layer of the cranial bones. Synonym: lamina externa cranii. (05 Mar 2000) |
| the outer | Ovarian extremity of the oviduct. (05 Mar 2000) |
| axis, principal | <microscopy> A line conceived as passing through the centre of a lens to connect the centres of curvature of the lens surfaces. The focal points of a lens lie on the principal axis. (05 Aug 1998) |
| principal | 1. Highest in rank, authority, character, importance, or degree; most considerable or important; chief; main; as, the principal officers of a Government; the principal men of a state; the principal productions of a country; the principal arguments in a case. "Wisdom is the principal thing." (Prov. Iv. 7) 2. Of or pertaining to a prince; princely. Principal axis. See Axis of a curve, under Axis. Principal axes of a quadric, a plane passing through the optical axis of a crystal. Origin: F, from L. Principalis. See Prince. Source: Websters Dictionary (01 Mar 1998) |
| 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) |