The Spinal Column

The spinal column consists of a series of bony vertebrae separated by intervertebral discs. The spinal column may be thought of as consisting of five regions: the cervical spine, thoracic spine, lumbar spine, sacrum and coccyx. The cervical region normally contains seven cervical vertebrae. The uppermost cervical vertebra, called the atlas, supports the occiput of the skull. The atlas is shaped like a ring and sits on top of the second cervical vertebra, the axis. There is no intervertebral disc between the atlas and the occiput, nor between the atlas and axis. The axis contains a special process, the odontoid process, which protrudes into the vertebral canal of the atlas. The odontoid process , also called the dens, supports the atlas and permits a large degree of rotation. Most of the rotation of the neck occurs between the atlas and axis, not between the lower cervical vertebrae. The atlas, axis and the other five cervical vertebrae beneath them form a gentle forward curve called the cervical lordosis.

The thoracic region normally contains twelve thoracic vertebrae. These vertebrae form a gentle backward curve called the thoracic kyphosis. The thoracic vertebrae articulate with the ribs. This region of the spine does not allow a great deal of motion.

In the lumbar region of the spine, there are normally five lumbar vertebrae. These are the largest of the vertebrae. Because they are fairly mobile and support the weight of the body, these vertebrae and their intervertebral discs are especially subject to degenerative changes with age. The lumbar vertebrae normally have a gentle forward curve called the lumbar lordosis.

The sacral region of the spine consists of five sacral vertebrae, however these fuse into a single sacrum in the adolescent. The sacrum has a gentle backward kyphosis. The sacrum articulates with the ilium and so transfers the weight of the body to the hips. The coccyx consists of four or five small bones which are usually fused in the adult. The coccyx is the remnant of the skeleton of the tail which is reabsorbed in the human fetus.

From the second cervical vertebra to the lumbosacral junction, successive vertebrae are separated by intervertebral discs. These act to absorb forces as the spinal column is compressed. The intervertebral disc consists of a tough, outer annulus fibrosus, and a soft, inner nucleus pulposus. Occasionally, the nucleus pulposus herniates through the annulus fibrosus. If the herniation presses on a spinal nerve or the spinal cord, it can produce symptoms such as radicular pain.

Vertebrae from the different regions of the spine have different jobs to perform, but they have certain structural features in common. Generally, each vertebra has a cylindrical anterior vertebral body which supports the weight which presses on the spinal column. Behind the vertebral body is the vertebral arch, consisting of a pedicle and lamina on each side. The laminae unite posteriorly and form a spinous process. Arising laterally from the pedicles are the transverse processes, which in the thoracic spine articulate with the ribs. The pedicles also support the superior and inferior articular processes, which form the intervertebral joints. On the superior articular process of the lumbar vertebra, there is also a small mammillary process. The various processes of the vertebrae are points of attachment for muscles, their tendons and ligaments. Posterior to the intervertebral disc and anterior to the intervertebral joints is the intervertebral foramen, the point where the spinal nerve leaves the vertebral canal.


English - French Glossary

annulus fibrosus: anneau fibreux ; articular process: apophyse ; cervical: cervical ; coccyx: coccyx ; intervertebral disc: disque intervertébral ; intervertebral foramen: trou de conjugaison ; kyphosis: cyphose ; lamina: lame ; lordosis: lordose ; lumbar:  lombaire ; mammillary (mamillary) process: tubercule mamillaire; odontoid process: apophyse odontoïde; pedicle: pédicule ; sacrum: sacrum ; scoliosis: scoliose ; spinal column: colonne vertébrale ; spinous process: apophyse épineuse ; thoracic: thoracique; transverse process: apophyse transverse ; vertebra: vertèbre ; vertebral body: plateau vertébral 

English - Japanese Glossary

annulus fibrosus: 線維輪 (senirin); articular process: 関節突起 (kansetsutokki); atlas: 環椎 (kantsui); axis:軸椎 (jikutsui); cervical vertebra(e): 頸椎 (keitsui); coccyx: 尾骨 (bikotsu); intervertebral disc: 椎間板 (tsuikanban); intervertebral foramen(a): 椎間孔 (tsuikankou); kyphosis: 後わん (kouwan); lamina: 椎弓板 (tsuikyuuban); lordosis: 前わん (zenwan); lumbar vertebra(e): 腰椎 (youtsui); mammillary (mamillary) process: 乳頭突起 (nyuutoutokki); nucleus pulposus: 髄核 (zuikaku); odontoid process: 歯突起; pedicle: 椎弓根 (tsuikyuukon); sacrum: 仙骨 (senkotsu); scoliosis: 側わん (sokuwan); spinal column: 脊柱 (sekichuu); spinous process:棘突起 (kyokutokki); thoracic vertebra(e): 胸椎 (kyoutsui); transverse process: 横突起 (outokki); vertebra(e): 椎骨 (tsuikotsu); vertebral body: 椎体 (tsuitai)

 

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