| neural tube defect | <neurology, paediatrics> Abnormal development during embryonic life of the neural tube producing congenital malformations of the nervous system due to closure failure of the neural tube. The structure gives rise to the central nervous system (the brain and spinal cord), and failure to close results in anencephaly (absence of the cranial vault and absence of most or all of the cerebral hemispheres of the brain) and spina bifida or meningomyelocele (open spina with exposure and protusion of the spinal cord). The risk of neuroal tube defects can be decreased by the mother taking folic acid during pregnancy. (04 Jul 1999) |
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| dorsal plate of neural tube | The thin layer of the embryonic neural tube connecting the alar plate's dorsally. Synonym: dorsal plate of neural tube. (05 Mar 2000) |
| dorsolateral plate of neural tube | The dorsal division of the lateral walls of the neural tube in the embryo; it gives rise to neurons relaying afferent impulses to higher centres; in the adult such neurons compose the sensory nuclei of the spinal cord and brainstem. Synonym: lamina alaris, alar plate of neural tube, dorsolateral plate of neural tube, lamina dorsalis, wing plate. (05 Mar 2000) |
| alar spine | A posterior and downward projection from the greater wing of the sphenoid bone on either side, located posterolateral to the foramen spinosum, so-named for its proximity to the sphenoidal spine; gives attachment to the sphenomandibular ligament. Synonym: processus spinosus, spina ossis sphenoidalis, alar spine, angular spine, spina angularis, spinous process. (05 Mar 2000) |
| angular spine | A posterior and downward projection from the greater wing of the sphenoid bone on either side, located posterolateral to the foramen spinosum, so-named for its proximity to the sphenoidal spine; gives attachment to the sphenomandibular ligament. Synonym: processus spinosus, spina ossis sphenoidalis, alar spine, angular spine, spina angularis, spinous process. (05 Mar 2000) |
| anterior inferior iliac spine | Spine on the anterior border of the ilium between the anterior superior iliac spine and the acetabulum; site of origin for the direct head of the rectus femoris muscle. Synonym: spina iliaca anterior inferior. (05 Mar 2000) |
| anterior nasal spine | A pointed projection at the anterior extremity of the intermaxillary suture; the tip, as seen on a lateral cephalometric radiograph, is used as a cephalometric landmark. Synonym: spina nasalis anterior. (05 Mar 2000) |
| anterior superior iliac spine | The anterior extremity of the iliac crest, which provides attachment for the inguinal ligament and the sartorius muscle. Synonym: spina iliaca anterior superior. (05 Mar 2000) |
| bamboo spine | In radiology, the appearance of the thoracic or lumbar spine with ankylosing spondylitis. (05 Mar 2000) |
| meatal spine | Small bony prominence anterior to the supramastoid pit at the posterosuperior margin of the bony external acoustic meatus. Synonym: spina suprameatica, Henle's spine, meatal spine, spina meatus. (05 Mar 2000) |
| cervical spine fractures | <radiology> Hyperflexion injury (46-79%), odontoid fracture, simple wedge fracture (stable), tear drop fracture, anterior subluxation, bilateral locked facets (unstable), anterior disc space narrowing, widened interspinous distance, clay shoveler's fracture hyperextension injury (20-38%), anteriorly widened disc space, prevertebral swelling, tear drop fracture, neural arch fracture of C1, subluxation (anterior/posterior), hangman's fracture flexion-rotation injury (12%), unilateral locked facets (stable) vertical compression (12%), Jefferson fracture, burst fracture lateral flexion/shearing (4-6%), uncinate fracture, isolated pillar fracture, transverse process fracture, lateral vertebral compression location (by frequency): C2,C6 greater than C5,C7 greater than C3,C4 greater than C1 see: atlas fracture, axis fracture, unstable fractures (12 Dec 1998) |
| cervical spine fusion | <radiology> (ankylosis) Posterior elements, JRA, vertebral bodies, block vertebrae, Klippel-Feil (12 Dec 1998) |
| mental spine | A slight projection, sometimes two, in the middle line of the posterior surface of the body of the mandible, giving attachment to the geniohyoid muscle (below) and the genioglossus (above). Synonym: spina mentalis, genial tubercle. (05 Mar 2000) |
| greater tympanic spine | The anterior edge of the tympanic notch (of Rivinus). Synonym: spina tympanica major. (05 Mar 2000) |
| cleft spine | See: spina bifida. (05 Mar 2000) |