1. Vertebral column Supports Skull Pectoral girdle Upper limb Thoracic cage Protects Spinal cord and the spinal nerve roots 1

2. Composed of 33 vertebrae 7 cervical 12 thoracic 5 lumbar 5 sacral 4 coccygeal 2

3. Because it is segmented, made of vertebrae, pads of fibrocartilage, the intervertebral discs join each vertebra The intervertebral discs form about 1/4 th of the length of column 3

4. Typical vertebra consists of rounded body, anteriorly Vertebral arch posteriorly. These enclose vertebral foramen, through which spinal cord runs. Arch consists of 7 processes Spinous process(1) Transverse process(2) Articular processes(4) 4

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6. Joints Between Two Vertebral Bodies Upper and lower surfaces of the bodies of adjacent vertebrae by thin plates of hyaline cartilage. Sandwiched between the plates of hyaline cartilage is an intervertebral disc of fibrocartilage. 6

7. 7 Each disc has a peripheral part, anulus fibrosus (consisting of concentric layers of collagen fibers), and a central part the nucleus pulposus (ovoid mass of gelatinous material collagen fibers and a few cartilage cells).

8. A sudden increase in compression load on vertebral column causes nucleus pulposus to thrust outward, where it may press on the spinal cord or the nerve roots causing pain. This mainly happens with advancing age collagen fibers of the anulus degenrates and as a result the anulus cannot contain the nucleus pulposus under stress. The 1 st, 2 nd cervical verterbrae, sacrum, and coccyx lacks intervertebral discs 8

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10. Joints between two vertebral arches Synocial joints between the supeerior and inferior articular processes of adjacent vertebrae. The articular facets are covered by hyaline cartilage and sorrounded by a capsular ligament. Supraspinous ligament,interspinous ligament, intertransverse ligaments and ligamentum flavum helps in stabilizing the joints In cervical region, the supraspinous and interspinous ligaments are greatly thickened to form strong ligamentum nuchae,which extends from 7 th cervical spine to the external occipital protuberance 10

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12. Atlanto-Occipital joints Synovial joints Between occipital condyles(present on either side of foramen magnum) and facets on the superior surfaces of the lateral masses of the atlas Capable of flexion, extension and lateral flexion. They do not rotate 12

13. Atlanto-Axial joints 3 synovial joints; 1 between odontoid process and the anterior arch of atlas 2 between the lateral masses of the bones Extensive rotation of the atlas and thus the head on the axis. 13

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15. Curves of verterbral column In fetus, the vertebral column has one continuous posterior convexity. In adult, the vertebral column exibits Cervical, posterior concavity Thoracic, posterior convexity Lumbar, posterior concavity and sacral, posterior convexity In old age, the intervetebral discs atropy gradual return of vertebral column to continuous posterior convexity 15

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