1. A section; a part of an organ or other structure delimited naturally, artificially, or by invagination from the remainder. See also metamere. 2. A territory of an organ having independent function, supply, or drainage. 3. To divide and redivide into minute equal parts.segmentum [NA] ; [L. segmentum, fr. seco, to cut]
anterior s.a delimited part or section of an organ or other structure which lies in front of or ventral to the other similar parts or sections. 1) segmentum anterius (hepar) [NA]; the anterior segment of the right lobe of the liver. 2) segmentum anterius (pulmo dexter et sinister) [NA]; [S 3]; the anterior segment of the superior lobe of the right and left lungs. 3) anterior segment of the eye; the intraocular segment of the eyeball occupied by the aqueous which lies in front of, and is separated from the vitreous-filled posterior segment by, the lens and zonule; it is subdivided by the iris into anterior and posterior chambers.segmentum anterius;
anterior basal s.anterior basal segment of inferior lobe of right and left lung; lies between middle lobe and diaphragm.segmentum basale anterius [NA] ;
anterior inferior s.anterior inferior segment of kidney.segmentum anterius inferius [NA] ;
anterior ocular s.that portion of the eye comprising the cornea, iris, lens, and their associated chambers and adnexa.
anterior superior s.anterior superior segment of kidney.segmentum anterius superius [NA] ;
apical s. 1. apical segment of the superior lobe of the right lung; 2. apical segment of the inferior lobe of the right and left lungs.segmentum superius (2) [NA] ; segmentum superius (1) [NA] , segmentum apicale, superior s. (2) ;
apicoposterior s.apicoposterior segment of superior lobe of left lung, composed of two segments and wedged between the anterior segment of the upper lobe and the oblique fissure.segmentum apicoposterius [NA] ;
arterial s.'s of kidneyrenal s.'s
bronchopulmonary s.the largest subdivision of a lobe of the lung; it is supplied by a direct tertiary (lobular) bronchus and a tertiary branch of the pulmonary artery; it is separated from adjacent segments by connective tissue septa.segmentum bronchopulmonale [NA] ;
cardiac s.medial basal s
cervical s.'s of spinal cordthe eight cervical segments [C1-C8] of the spinal cord which give rise to the eight pairs of cervical spinal nerves and constitute the cervical part of the spinal cord.segmenta medullae spinalis cervicalia;
coccygeal s.'s of spinal cordthe three coccygeal segments [Co1-Co3] of the spinal cord which give rise to the three pairs of coccygeal spinal nerves and constitute the coccygeal part of the spinal cord.
hepatic s.'sterritories of the liver with independent portobilioarterial distribution or independent venous drainage. The naming of segments in the NA is based upon the portobilioarterial distribution. See anterior s., lateral s., medial s., posterior s.segmenta hepatis, s.'s of liver;
hepatic venous s.'svenous s.'s of liver
inferior s.inferior segment of kidney, which typically consists of approximately the inferior third of the kidney viewed either anteriorly or posteriorly.segmentum inferius [NA] ;
inferior lingular s.inferior lingular segment of superior lobe of left lung; between superior lingular segment and oblique fissure.segmentum lingulare inferius [NA] ;
interannular s.internodal s
intermaxillary s.the primordial mass of tissue formed by the merging of the medial nasal prominences of the embryo; it contributes to the intermaxillary portion of the upper jaw, the prolabial portion of the upper lip, and the primary palate.
internodal s.the portion of a myelinated nerve fiber between two successive nodes.interannular s., internode, Ranvier's s., segmentum internodale;
Lanterman's s.'sthe divisions of the nerve fiber between the Schmidt-Lanterman incisures.
lateral s.a delimited part or section of an organ or other structure which lies farthest to the left or right side of the other similar parts or sections. 1) segmentum laterale (hepar) [NA]; the lateral segment of the left lobe of the liver. 2) segmentum laterale (pulmo dexter) [NA]; [S 4]; the lateral segment of the middle lobe of the right lung.segmentum laterale;
lateral basal s.lateral basal segment of inferior lobe of right and left lung; between anterior and posterior basal segments.segmentum basale laterale [NA] ;
s.'s of liverhepatic s.'s
lower uterine s.the inferior portion or isthmus of the uterus, the lower extremity of which joins with the cervical canal and, during pregnancy, expands to become the lower part of the uterine cavity.
lumbar s.'s of spinal cordthe five lumbar segments [L1-L5] of the spinal cord which give rise to the five pairs of lumbar spinal nerves and constitute the lumbar part of the spinal cord.segmenta medullae spinalis lumbaria;
medial s.a delimited part or section of an organ or other structure which lies closer or closest to the midline than the other similar parts or sections. 1) segmentum mediale (hepar) [NA]; the medial segment of the left lobe of the liver. 2) segmentum mediale (pulmo dexter) [NA]; [S 5]; the medial segment of the middle lobe of the right lung.segmentum mediale;
medial basal s.cardiac segment; medial basal segment of inferior lobe of right and left lung; can only be seen from medial and inferior surfaces since it does not reach lateral surface of lung.segmentum basale mediale [NA] , segmentum cardiacum [NA] , cardiac s;
posterior s.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) [NA]; the posterior segment of the right lobe of the liver; 2) segmentum posterius (pulmo dexter) [NA]; [S 2]; the posterior segment of the superior lobe of the right lung; 3) segmentum posterius (ren) [NA]; the posterior segment of the kidney; 4) camera vitrea bulbi [NA]; 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.segmentum posterius;
posterior s. of eyeballthe large space between the lens and the retina; it is filled with the vitreous body.camera vitrea bulbi [NA] , vitreous camera, vitreous chamber of eye;
posterior basal s.posterior basal segment of inferior lobe of right and left lungs; lies adjacent to vertebral column below superior segment.segmentum basale posterius [NA] ;
P-R s.that part of the electrocardiographic curve between the end of the P wave and the beginning of the QRS complex.
Ranvier's s.internodal s
renal s.'sregions of the kidney supplied by end arteries branching from the renal arteries; they are named anterior inferior s., anterius superior s., inferior s. , posterior s., and superior s.segmenta renalia [NA] , arterial s.'s of kidney;
RST s.the part of the electrocardiogram between the QRS complex and the T wave. Virtually never distinct in normal hearts in which it forms the initial limb of the T wave without an agreed endpoint.
s.'s of spinal cordportions of the spinal cord corresponding to the line of attachment of the roots of the individual spinal nerves. These are the cervical spinal cord segments [C1-C8]; the thoracic spinal cord segments [T1-T12]; the lumbar spinal cord segments [L1-L5]; the sacral spinal cord segments [S1-S5]; and the coccygeal spinal cord segments [Co1-Co3].segmenta medullae spinalis [NA] ;
s.'s of spleensplenic territories receiving independent arterial supply or drained by independent roots of the splenic vein.segmenta lienis;
S-T s.that part of the electrocardiographic tracing immediately following the QRS complex and merging into the T wave.
subapical s.an inconstant segment of the inferior lobe of the right and left lungs.segmentum subapicale, segmentum subsuperius, subsuperior s;
subsuperior s.subapical s
superior s. 1. the uppermost segment of the kidney; 2. apical s
superior lingular s.superior lingular segment of the superior lobe of the left lung; lies above inferior lingular segment.segmentum lingulare superius [NA] ;
sympathetic s.a divison of the sympathetic trunks based on the origins of the gray communicating branches.
upper uterine s.the main portion of the body of the gravid uterus, the contraction of which furnishes the chief force of expulsion in labor.
venous s.'s of the kidneyanatomical s.'s of the kidney drained by tributaries of the renal vein; not a true segmental distribution, since cross communication exists between the various tributaries within the kidney.
venous s.'s of livereach of the four territories of the liver separately drained by the hepatic veins.hepatic venous s.'s;
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