The cervical branch of the facial nerve is a small nerve located in the neck. It's a branch of the larger facial nerve (cranial nerve VII) and its primary function is to innervate the platysma muscle, a superficial muscle in the neck responsible for depressing the mandible and lip.
Anatomy and Function
- Location: This branch originates from the facial nerve and travels deep to the platysma muscle before innervating it. Its precise location can vary, but studies suggest it's reliably found within 1 cm below a perpendicular line from the angle of the mandible to a line drawn from the mastoid process. [Locating the cervical motor branch of the facial nerve: anatomy and...]
- Innervation: The cervical branch provides motor innervation to the platysma muscle. This muscle contributes to facial expressions, particularly those involving the lower face and neck. [The cervical branch of the facial nerve will be found on the deep surface of the platysma as it innervates this muscle...]
- Variability: The anatomy of the cervical branch exhibits significant variability depending on the overall branching pattern of the facial nerve and head anthropometry. [The cervical branch of the facial nerve varies depending on the facial nerve branching pattern and the anthropometric type of the head.]
- Clinical Significance: Injury to this branch can be distinguished from other facial nerve injuries, particularly those affecting the marginal mandibular branch. [Cervical branch injury can be distinguished from marginal mandibular nerve...] Studies continue to investigate the course and patterns of the platysma muscle innervation to better understand clinical presentations of related injuries. [The goals of this cadaver study were to document the course of the cervical branches of the facial nerve and investigate the pattern of platysma muscle...]
Further Considerations
While the primary known function is innervation of the platysma, the cervical branch may have other, less well-defined contributions. Further research is ongoing to fully elucidate its role and anatomical variations. The information provided here reflects currently available knowledge. Note that the facial nerve as a whole innervates several other muscles in the head and neck, including muscles of facial expression, the stapedius muscle (in the middle ear), the stylohyoid muscle, and the posterior belly of the digastric muscle. [Their function is to innervate the muscles of facial expression, the stapedius muscle, the stylohyoid muscle, and the posterior belly of the digastric muscle.]
