Cervical Spinal Nerves
The cervical part of the spine refers to the vertebra that make up the neck region. The cervical nerves are those that supply the cervical spine. There are seven cervical vertebra and eight pairs of cervical nerves.
The cervical nerves are numbered from C1 to C8. This numbering or naming is based on the lower cervical vertebra that the nerve runs through. C1 and C2 nerves control movements and sensation in the head and neck while C3 controls movement of the diaphragm. C4 controls the muscles of the upper body i.e., the deltoids that form the shoulders curves and the biceps that aid in movement and rotation of the elbow and forearm. C5 and C6 supply the wrist, C7 the triceps and finally C8 the hands.
The cervical nerves are a part of the peripheral nervous system (PNS). This is outside the central nervous system (CNS) that includes the brain and spinal cord and serves to connect the CNS with the other organs. The PNS is made up of nerves that branch out of the nerve roots of the spinal cord.
The first four cervical nerves combine together to form the cervical plexus. They supply the head and the neck regions. The last four cervical nerves combine to form the brachial plexus. This supplies the arm and upper back. Cervical plexus has two branches – the cutaneous and muscular.
Since the cervical nerves control many of the body’s movements and activities, injury or irritation to these nerves can cause serious complications. Irritation to the cervical nerves may happen due to a herniated cervical disc or cervical stenosis. Herniation occurs due to the cervical disc coming into contact with the nerve thus producing symptoms like numbness. Stenosis occurs when the cervical nerve is compressed. This brings about a deterioration in motor skills.