THE SPINAL NERVES
The spinal nerves act
as “telephone lines” carrying messages back and forth between the body and the spinal cord to control movement
and sensation. Each spinal nerve has two (2) roots;
1) The Front
aka Ventral Root carries motor impulses from the brain.
2) The Back
aka Dorsal Root carries sensory impulses to the brain.
The ventral and dorsal roots fuse together to form
a spinal nerve which travels down the spinal canal alongside the cord until it reaches its exit which is the Intervertebral
foramen. Once the nerve passes through the intervertebral foramen, it splits into two (2) and its branch has both motor and
sensory fibers.
1)
The Smaller Branch aka Posterior Primary Ramus turns posteriority
to supply the skin and muscles of the back of the body.
2) The Larger
Branch aka Anterior Primary Ramus turns anteriorly to supply the skin and muscles of the front of the body and forms most
of the major nerves.
The spinal nerves innervate specific areas and form a striped pattern across
the body called dermatomes. Medical professionals use this pattern to diagnose the location of a spinal nerve problem based
on the area of pain or muscle weakness.
There are thirty-one (31) pairs of spinal nerves and the spinal
nerves are numbered according to the vertebrae above which it exits the spinal canal.
1) The Eight (8) Cervical Spinal Nerves are C1 through C8.
2) The Twelve (12) Thoracic Spinal Nerves are T1 through T12.
3) The Five (5) Lumbar Spinal Nerves are L1 through L5.
4) The Five (5) Sacral Spinal Nerves are S1 through S5.
5) There is One (1) Coccygeal
Spinal Nerve.