The nervous system controls and coordinates all organs & structures of our human body. In this post, i will focus only on 'Spinal Nerves'.
Human body has spine at the back which is also called as 'Backbone' or 'Vertebral column'. Our human spine contains 33 small bones which we call 'Vertebrae'.
There are 7 cervical (neck region & represented as C), 12 thoracic (chest or upper back region & represented as T), 5 lumbar (low back region & represented as L), 5 sacral (triangular shared fused 5 bones & represented as S) and 4 coccygeal vertebrae (they are also fused bones).
|Human Vertebral Column|
[Source for image: Wikipedia]
The average length of human vertebral column is about 71cm in males (cervical part's length is 12.5 cm., the thoracic part measures 28 cm., the lumbar 18 cm., and the sacrum and coccyx 12.5 cm) & about 61cm in females.
The vertebral column protects 'Spinal cord' which contains 31 pairs of spinal nerves that control & coordinates various human parts. The Spinal Cord has a diameter of about human finger & is connected to the brain at the top.
There are 31 pairs of spinal nerves - 8 pair of cervical nerves (numbered C1-C8), 12 pair of thoracic nerves (numbered T1-T12), 5 pairs of lumbar nerves (numbered L1-L5), 5 pairs of sacral nerves (numbered S1-S5) & one pair of coccygeal nerves.
Following image would help identify the relation of various spinal nerves with respective human organs:
|Spinal Nerves Functions|
[Source for image: http://www.concordnhchiropractor.com/spinal_nerve.htm ]
Have an informed living !