Cervical spinal nerves, also known as cervical nerves, they are a group of 8 spinal nerves of the eight cervical vertebrae that are born from the spinal cord. These 8 vertebrae, which are known and numbered from C-1 to C-8, have their origin at the base of the skull.
All cervical spinal nerves, except C-1 (which normally has no dorsal root), are associated with a dermatome. A dermatome is a skin area supplied by a spinal nerve.
Spinal or spinal nerves
As we know, cervical spinal nerves encompass 8 of the spinal or spinal nerves. These, in turn, they are a set of nerves (approximately between 31 and 33 nerves) belonging to the somatic nervous system which have the function of innervating different parts of the body.
They are composed of a sensitive root and a motor root. The first type of fiber is what allows you to give sensitivity to the muscles you innervate. As for the motor roots, they will allow the muscles to contract automatically. Thanks to this composition, they reach their goal.
The spinal nerves, which encompass the cervical spinal nerves, are as follows:
8 pairs of cervical nerves (C1-C8).
12 thoracic nerves (T1-T12).
5 sacral nerves (S1-S5).
5 lumbar nerves (L1-L5).
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Characteristics of the spinal or spinal nerves
The cervical spinal nerves, belonging to the group of spinal nerves, they will share the same characteristics as the others.
First, as we have already mentioned, they are mixed nerves, that is, they are composed of both sensitive and motor fibers.
Second, all divisions of the ventral branches, except the thoracic (T1 to T12), they form several ramifications that are known as nerve plexuses. These plexuses appear in the cervical, brachial and lumbo sacral areas.
Within these interconnected branches, the fibers that have their origin in the ventral branches intersect and are distributed again so that each resulting branch contains fibers of different spinal nerves.
In addition, those that come from each ventral branch they travel to the periphery of the body by means of different routes in the ramifications.
For this reason, each muscle of one limb will receive an innervation of more than one spinal nerve. As a consequence, if there is damage in one of the segments of the spinal cord or in one of the roots, the limb does not have to be completely disabled.
Cervical spinal nerves
The ventral branches of the first four spinal nerves form the cervical plexus. Its ramifications they are cutaneous nerves that innervate the skin of the following areas transmitting sensory impulses:
Back of the head.
There are also ramifications that supplement the anterior muscles of the neck. Also, from this cervical plexus the phrenic nerve is born that groups fibers that come mainly from C-3 and C-4. The phrenic nerve goes along the chestto attend the diaphragm, the most important muscle in breathing.
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The ventral nerves of the cervical spinal nerves C-5 and C-8, next to the anterior primary branch of T-1, form the brachial plexus. Its ramifications are responsible for innervation of the shoulders and upper extremities.
Finally, the dorsal branches are responsible for the innervation of the cervical facets. Branches of the head and neck muscles also arise from these branches., as well as the skin between the vertex (upper surface of the head) and the shoulders.
Division of cervical spinal nerves
Like other spinal nerves, cervical spinal nerves divide into dorsal and ventral branches after leaving the spinal canal. As they leave the spinal cord, the ventral and dorsal roots join to form the spinal ganglion or dorsal root.
Then, these nodes are divided into:
Ventral or anterior branch: It is a thick bouquet. It intersects, divides and anastomoses with the anterior branches of other spinal nerves to form, as we have seen, the cervical plexus.
Dorsal or posterior bouquet: is the posterior branch of the common trunk. It is a branch much thinner than the previous branch.
In conclusion, cervical nerves are an important part of our nervous system that we must know and take care of because they are the basis of many ailments.