Measuring up to 18 inch in length, the dorsal neural tube gradually decreases in width while running downwards in the vertebral column, i.e. at the cervical regions the thickness is about 1/2 inch while reaching the lumbar vertebrae the size is reduced to just 1/4 inches in diameter. However, it is comparatively shorter in length than your bony spinal column and does not run along its entire length. On the whole, the ovoid structure of neural tube can be subdivided into 33 segments in human beings. Based on their association with the different regions of vertebrae, these segments can be grouped into five broader categories which are briefly described as under:
Cervical Segments
Being the anterior most segments of the spinal cord that run across seven cervical vertebrae, it is located along the neck region. The upper portion forms as many as eight pairs of cervical nerves which are named with the vertebra they emerge from, viz. C1, C2, C3, C4, ? C8. However, the C8 pair of cervical nerve emerges from the lower end of the C7 vertebral segment while all of other pairs emerge from the upper end of the respective vertebra.
Thoracic Segments
Running along the series of twelve T vertebrae in the thoracic region, they constitute 12 pairs of thoracic nerves each of which leaving the vertebral column below the associated vertebral division.
Lumbar Segments
It is one of the parts of spinal cord that is protected by five lumbar vertebrae, it gives rise to five pairs of nervous extensions each of which emerges below the associated vertebra.
Control of Reflexes
Another major task of this part of your CNS is the independent control and coordination of central nerve generators and certain reflexes. Such actions protect your body against dangerous stimuli by the generation and application of a quick response. Under such circumstances, the prolongation of response may inflict an irreparable damage to your body.
Ailments of the spinal nerve column are generally referred to as the disorders of central nervous system as it is its second major component. Besides injuries, a number of diseases have been identified affecting the region, viz. infections, inflammations, tumors, and degenerative disorders. Such spinal abnormalities are revealed through different clinical manifestations, like the loss of sensation, numbness, severe pain, and muscle weakness. The symptoms usually occur around the spinal cord but may also spread to arms and legs. For their amelioration, your health care provider may advise you different treatment measures mainly depending on the type and severity of the disorder, but the most frequently recommended strategies include drug administration and surgical therapy.
