vertebra

[ver´tĕ-brah] (L.)

any of the separate segments comprising the spine (vertebral column). The vertebrae support the body and provide the protective bony corridor (the spinal or vertebral canal) through which the spinal cord passes. The 33 bones that make up the spine differ considerably in size and structure according to location. There are seven cervical (neck) vertebrae, 12 thoracic (high back), five lumbar (low back), five sacral (near the base of the spine), and four coccygeal (at the base). The five sacral vertebrae are fused to form the sacrum, and the four coccygeal vertebrae are fused to form the coccyx.

The weight-bearing portion of a typical vertebra is the vertebral body, the most forward portion. This is a cylindrical structure that is separated from the vertebral bodies above and below by disks of cartilage and fibrous tissue. These intervertebral disks act as cushions to absorb the mechanical shock of walking, running, and other activity. Sometimes rupture or herniation of a disk may occur (see herniated disk).

A semicircular arch of bone (the vertebral arch) protrudes from the back of each vertebral body, surrounding the spinal cord. Directly in its midline a bony projection, the spinous process, grows backward from the arch. The spinous process can be felt on the back as a hard knob. Three pairs of outgrowths project from the arch. One of these protrudes horizontally on each side and in the thorax connects with the ribs. The remaining two form joints with the vertebrae above and below. The joints permit the spine to bend flexibly. The vertebrae are held firmly in place by a series of strong ligaments.

Structure of vertebrae.

cervical vertebrae the upper seven vertebrae, constituting the skeleton of the neck.

coccygeal vertebrae the lowest segments of the vertebral column, comprising three to five rudimentary vertebrae that form the coccyx.

cranial vertebra the segments of the skull and facial bones, regarded by some as modified vertebrae.

vertebra denta´ta the second cervical vertebra, or axis.

dorsal vertebrae thoracic vertebrae.

false vertebrae those vertebrae that normally fuse with adjoining segments: the sacral and coccygeal vertebrae.

lumbar vertebrae the five vertebrae between the thoracic vertebrae and the sacrum.

vertebra mag´na the sacrum.

odontoid vertebra the second cervical vertebra, or axis.

vertebra pla´na a condition of spondylitis in which the body of the vertebra is reduced to a sclerotic disk.

sacral vertebrae the vertebrae just below the lumbar vertebrae, usually five in number and fused to form the sacrum.

thoracic vertebrae the twelve vertebrae between the cervical and lumbar vertebrae, giving attachment to the ribs and forming part of the posterior wall of the thorax.

true vertebrae those segments of the vertebral column that normally remain unfused throughout life: the cervical, thoracic, and lumbar vertebrae.

Thoracic vertebrae

The vertebrae in the chest region to which the ribs attach.

Mentioned in: Spinal Instrumentation

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References in periodicals archive

In addition, X-rays detected serious osteoporosis and destruction of the pelvis, thoracic vertebrae, and lumbar vertebrae, together with compression fractures of thoracic vertebrae 11 and 12 and lumbar vertebrae 2 and 4 (Figure 1).

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The lumbar vertebrae were slightly larger than the thoracic vertebrae from the dorsal view.

The vertebral column, ribs, and sternum of the African giant rat (cricetomys gambianus waterhouse)

Cases of violent trauma from the Later Stone Age of South Africa Age Case Sex (years) Quoin Point (8) Female 20 - 30 Modder River (10) -- 12 - 13 -- 6 - 7 -- 1 - 1.5 Melkbosstrand (9) Female Adult -- 13 - 16 Langklip (6) Female Adult Snuifklip (11) Male Old adult Andrieskraal (7) Male Old adult Whitcher's Cave (6) -- Adult State Case Location of wound of wound Quoin Point (8) Thoracic vertebrae Perimortem (embedded arrows) Modder River (10) Cranial Perimortem Cranial Perimortem Cranial Perimortem Melkbosstrand (9) Cranial Perimortem Cranial Perimortem Langklip (6) Cranial Perimortem Snuifklip (11) Cranial Antemortem Andrieskraal (7) Cranial Antemortem Whitcher's Cave (6) Cranial Antemortem

Trauma and violence in the Later Stone Age of Southern Africa

The two thoracic vertebrae were missing the body and transverse processes due to nonfusion of these elements, but the spinous process, superior and inferior articular facets, and pedicle were present.

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The genes corresponding to the cervical vertebrae, the thoracic vertebrae, the lumbar vertebrae and the tailbone become activated at exactly the right moment one after another.

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She suffered fractured cervical and thoracic vertebrae and broken ribs for which she underwent emergency surgery at UHW before being transferred back to Bridgend.

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In the safety trial, patients will receive injections of about 2 million cells grown specifically to resemble precursors to spinal cord cells, within seven to 14 days of injuries to their thoracic vertebrae. In theory, the cells should grow into spinal tissues, helping repair the injury.

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Thoracic duct ligation has been the procedure of choice, with the duct typically ligated between the 8th and 12th thoracic vertebrae. (8) However, this type of repair is associated with significant morbidity (nearly 40% (2)) and mortality (as high as 25% (9,10)).

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On February 27, 1992, at the age of 24,1 sustained a complete spinal cord injury at T11/12 (that is, no feeling or sensation below thoracic vertebrae levels 11 and 12).I recall the accident vividly in my mind's eye.

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Spinous process angled angled of 4th through 10th 20-45[degrees] 50-90[degrees] thoracic vertebrae toward tail toward tail 11.

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Which is how he came to be enjoying the slopes at Outlane - Huddersfield's own Gstaad - and was later to be found having his thoracic vertebrae X-rayed in Calderdale General Hospital.

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We also excluded the posteriormost cervical vertebra (C7) because, in the cervids we examined, C7 is transitional to the thoracic vertebrae. It is foreshortened axially, has prominent keels, and lacks the box shape of the Manasquan bone.

Probable cervical vertebra of an extinct Ice Age elkmoose dredged from the inner continental shelf of central New Jersey, USA