lumbar vertebrae

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 [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.

Lumbar vertebrae

The vertebrae of the lower back below the level of the ribs.

lumbar vertebrae

five vertebrae (L1-L5) located between lowest thoracic (T12) and upper sacral (S1) vertebrae


pertaining to the loins.

lumbar epidural analgesia
see epidural anesthesia.
lumbar paralysis
paraplegia generally and specifically that due to cerebrospinal nematodiasis.
lumbar plexus
one formed by the ventral branches of the last four or five lumbar nerves in the psoas major muscle.
lumbar puncture
insertion of a needle and stylet into the subarachnoid space between the seventh lumbar vertebra and sacrum in most species except the dog, where the space between the sixth and seventh lumbar vertebrae is usually used; called also spinal puncture. A lumbar puncture may be done to measure the pressure of cerebrospinal fluid and obtain a specimen for examination, and to inject a contrast medium for special radiographic examinations such as myelography. As a therapeutic measure it is sometimes done to relieve intracranial pressure or to remove blood or pus from the subarachnoid space. A lumbar puncture also is necessary for injection of a spinal anesthetic.
lumbar spinal stenosis
see lumbosacral stenosis.
lumbar tap
see lumbar puncture (above).
lumbar vertebrae
the vertebrae between the thoracic vertebrae and the sacrum, numbering seven in dogs and cats, six in horses and cattle, and six or seven in sheep and pigs.
References in periodicals archive ?
The lengths of thoracic and lumbar vertebrae and the performance of Mongolia sheep.
Intake of alanine, arginine, and aspartic acid were not correlated with BMD of femur, hip, and lumbar vertebrae among people with SCI.
We have randomly selected 65 dry human lumbar vertebrae (20 atypical and 45 typical) obtained from 65 cadavers in the Bundelkhand region for IPD measurement.
Morphometry of lower lumbar vertebrae as seen on CT scans: newly recognized characteristics.
1,9) Spondylolysis is a breakdown of the vertebral structure; spondylolisthesis is a slippage or forward subluxation of the lower lumbar vertebrae on the sacrum.
Multifocal extensive spinal tuberculosis (Pott's disease) involving cervical, thoracic and lumbar vertebrae.
Jenny Janes of Ogmore-by- Sea, who, as a result of a serious car accident, required dynamic stabilisation surgery to have 10 titanium screws and a Teflon wire inserted to four of her lumbar vertebrae, uses the Ergonamic back for pain-free sitting on her sofa.
total body, arms, legs, trunk), the lumbar vertebrae, and hip regions (total hip, femoral neck, trochanter, femoral shaft).
A whole-body MRI detected multiple lesions involving the lower thoracic and lumbar vertebrae, the left 8th rib, right 10th rib, right femur, left acetabulum and lilac wing, left lace, and calvaria.
Yesterday Carl, who lives in Alnwick with girlfriend Jo Kemp, said: "I burst a lumbar vertebrae and there was a fragment of bone touching my spinal cord.
Mr Halliday suffered a broken lumbar vertebrae which left a fragment of bone pressing against a nerve in his spine.