Deep Cervical Fasciae of the Neck

Superficial (investing) layer of deep cervical fascia

• Surrounds the deeper parts of the neck.
• Splits to enclose the sternocleidomastoid and trapezius muscles.
• Is attached superiorly along the mandible, mastoid process, external occipital protuberance, and superior nuchal line of the occipital bone.
• Is attached inferiorly along the acromion and spine of the scapula, clavicle, and manubrium sternum.

Prevertebral layer of deep cervical fascia

• Is cylindrical and encloses the vertebral column and its associated muscles.
• Covers the scalene muscles and the deep muscles of the back.
• Attaches to the external occipital protuberance and the basilar part of the occipital bone and becomes continuous with the endothoracic fascia and the anterior longitudinal ligament of the bodies of the vertebrae in the thorax.

Carotid sheath

• Contains the common and internal carotid arteries, internal jugular vein , and vagus nerve.
• Does not contain the sympathetic trunk, which lies posterior to the carotid sheath and is enclosed in the prevertebral fascia.
• Blends with the prevertebral, pretracheal, and investing layers and also attaches to the base of the skull.

Pretracheal layer of deep cervical fascia

• Invests the larynx and trachea , encloses the thyroid gland , is continuous with the buccopharyngeal facia and contributes to the formation of the carotid sheath.
• Attaches superiorly to the thyroid and cricoid cartilages and inferiorly to the pericardium.

Alar fascia

• Is an ancillary layer of the deep cervical fascia between the pretracheal (or buccopharyngeal) and prevertebral fasciae, and forms a subdivision of the retropharyngeal space.
• Blends with the carotid sheath laterally and extends from the base of the skull to the level of the seventh cervical vertebra, where it merges with the pretracheal fascia.

Buccopharyngeal fascia

• Covers the buccinator muscles and the pharynx and blends with the pretracheal fascia.
• Is attached to the pharyngeal tubercle and the pterygomandibular raphe.

Pharyngobasilar fascia

• Is the fibrous coat in the wall of the pharynx and is situated between the mucous membrane and the pharyngeal constrictor muscles.

Retropharyngeal space

• Is the space between the prevertebral fascia and buccopharyngeal fascia, extending from the base of the skull into the posterior mediastinum.