| posterior segment | A delimited part or section of an organ or other structure which lies in back of or dorsal to the other similar parts or sections; 1) segmentum posterius (hepar); the posterior segment of the right lobe of the liver; 2) segmentum posterius (pulmo dexter); [S 2]; the posterior segment of the superior lobe of the right lung; 3) segmentum posterius (ren); the posterior segment of the kidney; 4) camera vitrea bulbi; vitreous camera; vitreous chamber of eye; the posterior intraocular segment of the eyeball occupied by the vitreous which lies behind the aqueous-filled anterior segment and is separated from it by the lens and zonule. Synonym: segmentum posterius. (05 Mar 2000) |
|---|---|
| posterior segment of eyeball | The large space between the lens and the retina; it is filled with the vitreous body. Synonym: camera vitrea bulbi, vitreous camera, vitreous chamber of eye. (05 Mar 2000) |
| P-R segment | That part of the electrocardiographic curve between the end of the P wave and the beginning of the QRS complex. (05 Mar 2000) |
| segment | <biology> A portion of a larger body or structure, set off by natural or arbitrarily established boundaries. Origin: L. Segmentum = a piece cut off (18 Nov 1997) |
| segment long spacing | <biochemistry> Abnormal packing pattern of collagen molecules formed if ATP is added to acidic collagen solutions, in which lateral aggregates of molecules are produced. Each aggregate is 300 nm long and the molecules are all in register. If segment long spacing aggregates are overlapped with a quarter stagger, the 67 nm banding pattern of normal fibrils is reconstituted. Acronym: SLS (18 Nov 1997) |
| segment polarity gene | <molecular biology> A segmentation gene, responsible for specifying anterior posterior polarity within individual embryonic segments. In Drosophila, there are at least 10 such genes, for example gooseberry. (18 Nov 1997) |
| neural segment | Alternate swellings and constrictions seen along the neuraxis at early stages of neural tube development, thought to be evidence of intrinsic segmentation in the CNS. Neuromeres or segments in the hindbrain region are called rhombomeres and have been shown to be lineage restriction units, each constructing a defined piece of hindbrain. (18 Nov 1997) |
| S-T segment | That part of the electrocardiographic tracing immediately following the QRS complex and merging into the T wave. (05 Mar 2000) |
| subapical segment | An inconstant segment of the inferior lobe of the right and left lungs. Synonym: segmentum subapicale, segmentum subsuperius, subsuperior segment. (05 Mar 2000) |
| subsuperior segment | An inconstant segment of the inferior lobe of the right and left lungs. Synonym: segmentum subapicale, segmentum subsuperius, subsuperior segment. (05 Mar 2000) |
| superior lingular segment | Superior lingular segment of the superior lobe of the left lung; lies above inferior lingular segment. Synonym: segmentum lingulare superius. (05 Mar 2000) |
| superior segment | The uppermost segment of the kidney. Synonym: apical segment. (05 Mar 2000) |
| sympathetic segment | A divison of the sympathetic trunks based on the origins of the gray communicating branches. (05 Mar 2000) |
| D gene segment | <molecular biology> Diversity gene segment. Part of the gene for the immunoglobin heavy chain, it codes for part of the hypervariable region of the VH domain and is located between the VH and JH segments. There are probably about 20 different D segments. (18 Nov 1997) |
| inferior lingular segment | Inferior lingular segment of superior lobe of left lung; between superior lingular segment and oblique fissure. Synonym: segmentum lingulare inferius. (05 Mar 2000) |