| dorsal position | The posture of an individual lying face up. (12 Dec 1998) |
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| dorsal primary ramus of spinal nerve | <anatomy, nerve> The smaller, posteriorly-directed major terminal branch (with the ventral primary ramus) of all 31 pairs of mixed spinal nerves, formed at the intervertebral foramen and turning abruptly posteriorly to divide into lateral and medial branches, both of which will supply the deep (true) muscles of the back. The medial branch (rami medialis ) of the dorsal primary ramus also supplies articular branches to the zygopophyseal joints and the periosteum of the vertebral arch. In the neck and upper back, the medial branch continues through the deep and superficial back muscles to supply overlying skin; in the lower back, the lateral branch does this. Nomina Anatomica lists dorsal primary rami as "rami dorsales" for each group of spinal nerves: 1) cervical (nervorum cervicalium ), 2) thoracic (nervorum thoracicorum ), 3) lumbar (nervorum lumbalium ), 4) sacral (nervorum sacralium ), and 5) coccygeal (nervi coccygei ). Synonym: ramus dorsalis nervorum spinalium, ramus dorsalis, rami posteriores nervorum spinalium, dorsal branch, posterior primary division. (05 Mar 2000) |
| dorsal reflex | Contraction of the muscles of the back elicited by cutaneous stimulation over the erector spinal muscle. (05 Mar 2000) |
| dorsal root | The sensory root of a spinal nerve, having a dorsal root ganglion containing the nerve cell bodies of the fibres conveyed by the root in its distal end. Synonym: radix posterior, radix sensoria, posterior root, radix dorsalis. (05 Mar 2000) |
| dorsal root ganglion | <anatomy> Enlargement of the dorsal root of the spinal cord containing cell bodies of afferent spinal neurons. Neural outgrowth from dorsal root ganglia has been studied extensively in vitro. (18 Nov 1997) |
| dorsal sacrococcygeal muscle | <anatomy> An inconstant and poorly developed muscle on the dorsal surfaces of the sacrum and coccyx, the remains of a portion of the tail musculature of lower animals. Synonym: musculus sacrococcygeus dorsalis, dorsal sacrococcygeal muscle, musculus extensor coccygis, musculus sacrococcygeus posterior. (05 Mar 2000) |
| dorsal sacrococcygeus muscle | <anatomy> An inconstant and poorly developed muscle on the dorsal surfaces of the sacrum and coccyx, the remains of a portion of the tail musculature of lower animals. Synonym: musculus sacrococcygeus dorsalis, dorsal sacrococcygeal muscle, musculus extensor coccygis, musculus sacrococcygeus posterior. (05 Mar 2000) |
| dorsal sacroiliac ligaments | The heavy fibrous bands that pass from the ilium to the sacrum posterior to the sacroiliac joint. Synonym: ligamenta sacroiliaca posteriora, dorsal sacroiliac ligaments, ligamentum sacroiliacum posterius. (05 Mar 2000) |
| dorsal scapular artery | <anatomy, artery> Origin, subclavian or as the deep branch of the transverse cervical; distribution, passes deep to the rhomboid muscles, supplying them and other muscles and skin along the vertebral border of the scapula; anastomoses, suprascapular and scapular circumflex. Synonym: arteria dorsalis scapulae, rami profundi arteriae transversae cervicis, ramus profundus arteriae transversae colli, arteria scapularis dorsalis, arteria scapularis descendens, deep branch of the transverse cervical artery, descending scapular artery, ramus profundus arteria scapularis descendens. (05 Mar 2000) |
| dorsal scapular nerve | <anatomy, nerve> Arises from ventral primary rami of the fifth to seventh cervical nerves and passes downward to supply the levator scapulae and the rhomboideus major and minor muscles. Synonym: nervus dorsalis scapulae, dorsal nerve of scapula, nerve to rhomboid, posterior scapular nerve. (05 Mar 2000) |
| dorsal scapular vein | <anatomy, vein> The vena comitans of the descending scapular artery; it is a tributary to the subclavian or the external jugular vein. Synonym: vena scapularis dorsalis. (05 Mar 2000) |
| dorsal spine | The series of vertebrae that extend from the cranium to the coccyx, providing support and forming a flexible bony case for the spinal cord. Synonym: columna vertebralis, backbone, dorsal spine, rachis, spina dorsalis, spina, spina, spinal column, spine, vertebrarium. (05 Mar 2000) |
| dorsal surface | The dorsal surface of a structure such as the sacrum and the scapula. Synonym: facies dorsalis. (05 Mar 2000) |
| dorsal surface of digit | The dorsal surface of a finger or toe. Synonym: facies digitalis dorsalis. (05 Mar 2000) |
| dorsal surface of sacrum | The posterosuperior aspect of the sacrum marked by a median and two lateral sacral crests between which four dorsal sacral foramina are located on each side. Synonym: facies dorsalis ossis sacri. (05 Mar 2000) |