The cervical plexus is a complex network of nerves found in the region of the neck and upper chest. This plexus is responsible for the innervation of various structures such as the muscles of the neck, skin, glands and certain joints in the region. Understanding the anatomy and functions of the cervical plexus is essential for health professionals, as any injury to this area can have significant consequences on the mobility and sensitivity of the neck and shoulders.

Parts of the Cervical Plexus

The cervical plexus is formed by the union of the spinal nerves C1, C2, C3 and C4. These nerves originate in the spinal cord and branch to form a network of nerve fibers that extend throughout the cervical region. The main parts of the cervical plexus are described below:

Cervical Nerve 1 (C1)

The C1 nerve is considered a cranial nerve due to its embryonic origin, despite being anatomically considered a spinal nerve. This nerve is small and often fuses with the C2 nerve. Its distribution includes the posterior region of the head and neck, as well as the alar membrane of the atlas. The C1 nerve is not part of the main network of the cervical plexus.

Cervical Nerve 2 (C2)

The C2 nerve is the largest of the cervical nerves and plays an important role in innervation of the head and neck. It branches into several nerves that participate in the innervation of the suboccipital muscles, the skin of the posterior region of the head and neck, and the atlanto-occipital joint.

Cervical Nerve 3 (C3)

The C3 nerve is another crucial component of the cervical plexus. This nerve innervates the scalene muscles, the skin of the lateral region of the neck, and certain muscles of the anterior region of the neck. Additionally, the C3 nerve contributes to the innervation of the acromioclavicular joint.

Cervical Nerve 4 (C4)

Finally, the C4 nerve completes the formation of the cervical plexus along with the nerves C1, C2 and C3. This nerve innervates the lower region of the neck and contributes to the innervation of the infraclavicular muscles, as well as the skin of the supraclavicular region.

In addition to these cervical nerves, the cervical plexus is interconnected with other plexuses. nerves, such as the brachial plexus, which is responsible for the innervation of the arm and hand. This connection between the plexuses is essential for the proper functionality of the upper extremity and neck.

Functions of the Cervical Plexus

The cervical plexus performs multiple functions in the human body, being crucial for movement and sensitivity of the cervical region and upper chest. Some of the most important functions of the cervical plexus are:

Innervation of the Neck Muscles

The nerves of the cervical plexus innervate the muscles of the neck, which is essential for mobility and the stability of this region. Muscles such as the trapezius, sternocleidomastoid and scalenes receive innervation from the cervical plexus, which allows movements such as rotation, flexion and extension of the neck.

Cutaneous Innervation

In addition to innervating muscles, the cervical plexus also provides cutaneous innervation through its nerve branches. Skin sensitivity in the cervical region, the back of the head and neck, and the supraclavicular region is largely due to the innervation of the cervical plexus. This function is essential for the perception of touch, temperature and pain in these areas.

Control of the Atlanto-occipital Joint

The cervical plexus participates in the control of the atlanto-occipital joint, which is the joint between the atlas and the skull. Adequate innervation of this joint is essential for the functionality of the head and neck, as well as for the coordination of movements such as flexion and extension of the neck.

Relationship with the Autonomous Nervous System

In addition to its motor and sensory functions, the cervical plexus also has a connection with the autonomic nervous system. Some nerve fibers in the cervical plexus are involved in regulating sympathetic activity in the cervical region and upper chest, affecting processes such as heart rate, blood pressure, and sweating.

Injuries of the Cervical Plexus

Injuries to the cervical plexus can have serious consequences for the functionality of the cervical region and the upper extremity. Some of the most common injuries that can affect the cervical plexus are:

Cervicobrachial Neuralgia

Cervicobrachial neuralgia is a painful disorder that affects the nerves of the cervical plexus, causing pain radiating from the neck to the arm. This condition can result from nerve compression, irritation, or injury to the cervical nerves, causing symptoms such as pain, tingling, weakness, and loss of sensation in the arm and hand.

Traumatic Injuries

Traumatic injuries, such as those caused by car accidents, falls, or sports injuries, can cause damage to the cervical plexus. These injuries can affect the integrity of the cervical nerves and compromise the functionality of the muscles and sensitivity of the cervical region and the upper extremity.

Cervical Tunnel Syndrome

Cervical Tunnel Syndrome Cervical tunnel is another disorder that can affect the cervical plexus. In this syndrome, compression of the cervical nerves in the neck region can cause pain, numbness, weakness, and tingling sensations in the neck, shoulders, arms, and hands. Treatment of this condition may require physical therapy, medications, or, in severe cases, surgery.

Conclusions

In conclusion, the cervical plexus is an anatomically and functionally important structure in the body human. Its role in the innervation of neck muscles, skin, joints and the relationship with the autonomic nervous system make it a vital component for the mobility and sensitivity of the cervical region and upper chest. Understanding the anatomy and functions of the cervical plexus is essential for the proper diagnosis and treatment of injuries that may affect this area, thus improving the quality of life of patients.