SPINE-The spine (backbone) is the framework over which the body is built. It plays a vital role in mobility, stability and protection of the spinal cord. It is made up of 33 bony segments called vertebra/vertebral bones. The upper 24 vertebrae are highly mobile with intervening jelly like fibrous tissue called intervertebral discs between them. The lower vertebrae are fused. The vertebra and discs together form the spinal column from the head to the pelvis.
VERTEBRA-Each vertebra is made up of two parts, the front cylindrical strong portion called the body and the back portion is referred to as the vertebral or neural arch around the spinal cord.
The individual vertebrae are named according to their region and position. From top to bottom, the vertebrae are:
Cervical spine: 7 vertebrae (C1–C7)
Thoracic spine: 12 vertebrae (T1–T12)
Lumbar spine: 5 vertebrae (L1–L5)
Sacrum: 5 (fused) vertebrae (S1–S5)
Coccyx: 4 (3–5) (fused) vertebrae (Tailbone)
The laminae are a pair of flat arched bones that form a component of the vertebral arch. The transverse processes spread out from the side of the pedicles, like wings, and help to anchor the surrounding muscle. The spinous process extend backwards at the apex of the laminae.It is palpable directly under the skin.INTERVERTEBRAL DISC
The upper 24 vertebrae are highly mobile with intervening jelly like fibrous tissue called intervertebral discs between them. They act as shock-absorbers of the spine and are also responsible for mobility. Each disc is made up of the annulus fibrosus (outer, fibrous ring of an intervertebral disc) which allows the nucleus pulposus (the soft, central portion of an intervertebral disc) to stay contained within.SPINAL CANAL
The spinal canal is a longitudinal space formed by the placement of vertebrae on top of each other. The spinal canal is formed by the vertebral body in front and the vertebral arch on the other sides and protects the spinal cord along the whole lengthPARTS OF THE SPINE
The spine can be divided into 4 parts: cervical (neck area), thoracic (mid-back), lumbar and sacral region (low back area). The thoracic spine has an outward curve called kyphosis, whereas the lumbar spine has a slightly inward curve, which is called lordosis.FACET JOINTS
These are two interlocking bony knobs connecting two vertebrae at any level, one on either side of the spine. These joints are meant for stability and also aid in the free movement of the spine. Articular cartilage covers the surfaces of the facet joints to assist in smooth, frictionless movement between the bones in the joint.NEURAL FORAMEN
There are a pair of small holes/narrow tunnels between two vertebrae on either side, through which two nerves leave the spine. Each nerve has a sensory part(for sensation) and a motor part to supply muscles. These nerves can get compressed due to disc prolapse, ageing (degeneration), injury, trauma,bone spurs etc. which result in narrowing of the foramen and compression of the nerve.