lumbar vertebrae


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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.

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

lumbar

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 ?
Quantitative three-dimensional anatomy of cervical, thoracic and lumbar vertebrae of Chinese Singaporeans.
The absence of clinically detectable metastases in the classic landing sites for rectal carcinoma strongly suggests that spread to the pelvis, lumbar vertebrae, and beyond occurred via the Batson plexus to the vertebral venous plexus.
Fractures and dislocations of the lumbar vertebrae (author's transl)].
Tenderness was present on thoracic and lumbar vertebrae and left lumbosacral region.
The spinal processes in the lower thoracic and lumbar vertebrae were painful to palpation.
This painless exam entails simple X-rays of the hip and lumbar vertebrae in the spine, which are then examined to measure the bones' thickness.
MRI of the lumbar vertebrae demonstrated a soft tissue mass at the level of the L4 vertebra corpus that caused compression on the dural sac and right L5 nerve root (Fig.
Her lumbar vertebrae had to be pinned and a gap in her spine filled with a bone graft.
The CSC Tiscali rider, who fractured his lumbar vertebrae in February when he fell from a ladder at his house in Geneva, beat off the challenge of Lampre's Belgian rider Ludo Dierckxsens in a two-man sprint to the line as the Tour returned to France after a brief excursion through Belgium.
The DUX 8888 has a unique mechanical system, controlled by a crank, which adjusts the level of support targeting the lumbar vertebrae.
His initial workup with gallium scans showed an increased uptake at the level of the fourth and fifth lumbar vertebrae.
The globe-trotting seven-year-old, trained by Francois Doumen, slipped his lumbar vertebrae during trackwork and has been withdrawn from the Group One contest a week tomorrow.