| ramus ventralis nervi spinalis | <anatomy, nerve> The larger, anterolaterally-directed major terminal branch (with the dorsal primary ramus) of all 31 pairs of mixed spinal nerves, formed at the intervertebral foramen. Most ventral primary rami, especially those involved in the innervation of the limbs, participate in the formation of the major nerve plexuses (cervical, brachial, and lumbosacral) and lose their identities. Most in the thoracic region, however, remain separate from adjacent rami to become the intercostal and subcostal nerves. Ventral primary rami provide innervation to the anterolateral body wall and trunk. Nomina Anatomica lists ventral primary rami as "rami ventrales" for each group of spinal nerves: 1) cervical (nervorum cervicalium ), 2) thoracic (nervorum thoracicorum ), 3) lumbar (nervorum lumbalium ), 4) sacral (nervorum sacralium )m, and 5) coccygeal (nervi coccygei ). Synonym: ramus ventralis nervi spinalis, anterior primary division. (05 Mar 2000) |
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| pars cervicalis medullae spinalis | The part of the spinal cord that consists of the eight cervical segments and gives rise to the first eight pairs of spinal nerves. Synonym: pars cervicalis medullae spinalis. (05 Mar 2000) |
| pars coccygea medullae spinalis | The terminal part of the spinal cord consisting of the three coccygeal segments of the spinal cord from which the three pairs of coccygeal nerves originate. Synonym: pars coccygea medullae spinalis, segmenta medullae spinalis coccygea. (05 Mar 2000) |
| pars lumbalis medullae spinalis | lumbar part |
| pars sacralis medullae spinalis | The part of the cord from which consists of the five sacral segments of the spinal cord (S1-S5) and from which five pairs of sacral nerves originate. Synonym: pars sacralis medullae spinalis, segmenta medullae spinalis sacralia. (05 Mar 2000) |
| pars spinalis nervi accessorii | <anatomy> An alternate term for spinal root of accessory nerve. (05 Mar 2000) |
| pars thoracica medullae spinalis | The part of the spinal cord which consists of the twelve thoracic segments of the spinal cord from which the twelve pairs of thoracic nerves originate. Synonym: pars thoracica medullae spinalis, segmenta medullae spinalis thoracica. (05 Mar 2000) |
| medulla spinalis | <anatomy> Elongated, approximately cylindrical part of the central nervous system of vertebrates that lies in the vertebral canal and from which the spinal nerves emerge. (18 Nov 1997) |
| chorda spinalis | <anatomy> Elongated, approximately cylindrical part of the central nervous system of vertebrates that lies in the vertebral canal and from which the spinal nerves emerge. (18 Nov 1997) |
| segmenta medullae spinalis | Portions 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 Origin: L1-L5]; the sacral spinal cord segments [S1-S5]; and the coccygeal spinal cord segments [Co1-Co3]. Synonym: segmenta medullae spinalis. (05 Mar 2000) |
| segmenta medullae spinalis cervicalia | The 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. Synonym: segmenta medullae spinalis cervicalia. (05 Mar 2000) |
| segmenta medullae spinalis coccygea | The terminal part of the spinal cord consisting of the three coccygeal segments of the spinal cord from which the three pairs of coccygeal nerves originate. Synonym: pars coccygea medullae spinalis, segmenta medullae spinalis coccygea. (05 Mar 2000) |
| segmenta medullae spinalis lumbaria | The five lumbar segments of the spinal cord which give rise to the five pairs of lumbar spinal nerves and constitute the lumbar part of the spinal cord. Synonym: segmenta medullae spinalis lumbaria. (05 Mar 2000) |
| segmenta medullae spinalis sacralia | The part of the cord from which consists of the five sacral segments of the spinal cord (S1-S5) and from which five pairs of sacral nerves originate. Synonym: pars sacralis medullae spinalis, segmenta medullae spinalis sacralia. (05 Mar 2000) |
| segmenta medullae spinalis thoracica | The part of the spinal cord which consists of the twelve thoracic segments of the spinal cord from which the twelve pairs of thoracic nerves originate. Synonym: pars thoracica medullae spinalis, segmenta medullae spinalis thoracica. (05 Mar 2000) |