Deep investing cervical fascia

The deep investing cervical fascia (a.k.a. the investing layer of the deep cervical fascia) is the outermost component of the deep cervical fascial system and forms a complete fibrous envelope around the neck. It lies deep to the superficial investing cervical fascia and platysma, and encircles the entire neck, enclosing the sternocleidomastoid and trapezius muscles, and contributing fascial sheaths to the submandibular and parotid glands.

Fascial attachments

• Superiorly, the deep investing cervical fascia attaches to the external occipital protuberance, superior nuchal line, mastoid process, zygomatic arch, and inferior border of the mandible, extending upward to invest the digastric and stylohyoid muscles.

• Inferiorly, the investing layer is continuous with the clavipectoral fascia and attaches to the manubrium, clavicles, acromion, and spine of the scapula.

• Posteriorly, it anchors to the ligamentum nuchae and spinous processes of the cervical vertebrae.

Functions

Functionally, the investing fascia provides support, protection, and compartmentalization for the superficial structures of the neck, serving as a barrier to the spread of infection and as a gliding surface for underlying musculature during neck movement.