The deep cervical fascia (or fascia colli in older texts) lies under cover of the

platysma The platysma muscle is a superficial muscle of the human neck that overlaps the sternocleidomastoid. It covers the anterior surface of the neck superficially. When it contracts, it produces a slight wrinkling of the neck, and a "bowstring" effec ...

, and invests the muscles of the neck; it also forms sheaths for the carotid vessels, and for the structures situated in front of the

vertebral column The vertebral column, also known as the backbone or spine, is part of the axial skeleton. The vertebral column is the defining characteristic of a vertebrate in which the notochord (a flexible rod of uniform composition) found in all chordate ...

. Its attachment to the hyoid bone prevents the formation of a

dewlap A dewlap is a longitudinal flap of skin or similar flesh that hangs beneath the lower jaw or neck of many vertebrates. More loosely, it can be various similar structures in the neck area, such as those caused by a double chin or the submandibul ...

. The investing portion of the fascia is attached behind to the ligamentum nuchæ and to the spinous process of the seventh

cervical vertebra In tetrapods, cervical vertebrae (singular: vertebra) are the vertebrae of the neck, immediately below the skull. Truncal vertebrae (divided into thoracic and lumbar vertebrae in mammals) lie caudal (toward the tail) of cervical vertebrae. In sa ...

. The ''alar fascia'' is a portion of the ''deep cervical fascia''.

Divisions

The deep cervical fascia is often divided into a superficial, middle, and deep layer. The superficial layer is also known as the investing layer of deep cervical fascia. It envelops the trapezius, sternocleidomastoid, and muscles of facial expression. It also contains the submandibular and parotid salivary gland as well as the muscles of mastication (the masseter, pterygoid, and temporalis muscles). The middle layer is also known as the pretracheal fascia. It envelopes the strap muscles (sternohyoid, sternothyroid, thyrohyoid, and omohyoid muscles). It also surrounds the pharynx, larynx, trachea, esophagus, thyroid, parathyroids, buccinators, and constrictor muscles of the pharynx. The deep layer is also known as the

prevertebral fascia The prevertebral fascia (or prevertebral layer of cervical fascia) is a fascia in the neck. Variations In some literature, the prevertebral fascia also includes the other fascial layers extending around the vertebral column and enclosing all mus ...

. It surrounds the paraspinous muscles and cervical vertebrae. The

carotid sheath The carotid sheath is an anatomical term for the fibrous connective tissue that surrounds the vascular compartment of the neck. It is part of the deep cervical fascia of the neck, below the superficial cervical fascia meaning the subcutaneous adip ...

is also considered a component of the deep cervical fascia.

Superior extent of the investing fascia

Above, the fascia is attached to the

superior nuchal line The nuchal lines are four curved lines on the external surface of the occipital bone: * The upper, often faintly marked, is named the highest nuchal line, but is sometimes referred to as the Mempin line or linea suprema, and it attaches to the epi ...

of the occipital bone, to the

mastoid process The mastoid part of the temporal bone is the posterior (back) part of the temporal bone, one of the bones of the skull. Its rough surface gives attachment to various muscles (via tendons) and it has openings for blood vessels. From its borders, ...

of the

temporal bone The temporal bones are situated at the sides and base of the skull, and lateral to the temporal lobes of the cerebral cortex. The temporal bones are overlaid by the sides of the head known as the temples, and house the structures of the ears. ...

, and to the whole length of the inferior border of the body of the

mandible In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower teeth in place. The mandible sits beneath the maxilla. It is the only movable bone ...

. Opposite the

angle of the mandible __NOTOC__ The angle of the mandible (gonial angle) is located at the posterior border at the junction of the lower border of the ramus of the mandible. The angle of the mandible, which may be either inverted or everted, is marked by rough, obliq ...

the fascia is very strong, and binds the anterior edge of the sternocleidomastoideus firmly to that bone. Between the mandible and the mastoid process it ensheathes the

parotid gland The parotid gland is a major salivary gland in many animals. In humans, the two parotid glands are present on either side of the mouth and in front of both ears. They are the largest of the salivary glands. Each parotid is wrapped around the ma ...

—the layer which covers the gland extends upward under the name of the parotideomasseteric fascia and is fixed to the

zygomatic arch In anatomy, the zygomatic arch, or cheek bone, is a part of the skull formed by the zygomatic process of the temporal bone (a bone extending forward from the side of the skull, over the opening of the ear) and the temporal process of the zygo ...

. It also contributes to the sheath of the digastric. At the level of the jaw, it splits to enclose the submandibular gland, with the upper leaflet inserting on the mylohyoid line just inferior to mylohyoid and the inferior leaflet inserting onto the lower margin of the jaw. The posterior portion of the upper leaflet helps separate the parotid gland from the submandibular gland where the mylohyoid is deficient while the posterior border is thickened into a strong band extending between the angle of the jaw and the

temporal styloid process The temporal styloid process is a slender bony process of the temporal bone extending downward and forward from the undersurface of the temporal bone just below the ear. The styloid process gives attachments to several muscles, and ligaments. Str ...

, forming the stylomandibular ligament. It is complemented by the pterygospinous ligament, which stretches from the upper part of the posterior border of the

lateral pterygoid plate The pterygoid processes of the sphenoid (from Greek ''pteryx'', ''pterygos'', "wing"), one on either side, descend perpendicularly from the regions where the body and the greater wings of the sphenoid bone unite. Each process consists of a me ...

to the spinous process of the sphenoid. It occasionally ossifies, and in such cases, between its upper border and the base of the skull, a foramen is formed which transmits the branches of the mandibular nerve to the muscles of mastication.

Inferior extent of the investing fascia

Below, the fascia is attached to the thoracic outlet (

acromion In human anatomy, the acromion (from Greek: ''akros'', "highest", ''ōmos'', "shoulder", plural: acromia) is a bony process on the scapula (shoulder blade). Together with the coracoid process it extends laterally over the shoulder joint. The ac ...

clavicle The clavicle, or collarbone, is a slender, S-shaped long bone approximately 6 inches (15 cm) long that serves as a strut between the shoulder blade and the sternum (breastbone). There are two clavicles, one on the left and one on the r ...

, and manubrium). In doing so, it bifurcates into two layers, superficial and deep. The former is attached to the anterior border of the manubrium, the latter to its posterior border and to the interclavicular ligament. Between these two layers is a slit-like interval, the suprasternal space (space of Burns); it contains a small quantity of areolar tissue, the lower portions of the

anterior jugular veins The anterior jugular vein is a vein in the neck. Structure The anterior jugular vein lies lateral to the cricothyroid ligament. It begins near the hyoid bone by the confluence of several superficial veins from the submandibular region. Its t ...

and their transverse connecting branch, the sternal heads of the sternocleidomastoid, and sometimes a

lymph gland A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that include ...

Deeper fascial layers

The fascia which lines the deep surface of the sternocleidomastoideus gives off the following processes: * A process envelops the tendon at the

omohyoideus The omohyoid muscle is a muscle that depresses the hyoid. It is located in the front of the neck, and consists of two bellies separated by an intermediate tendon. The omohyoid muscle is proximally attached to the scapula and distally attached to t ...

, and binds it down to the sternum and first

costal cartilage The costal cartilages are bars of hyaline cartilage that serve to prolong the ribs forward and contribute to the elasticity of the walls of the thorax. Costal cartilage is only found at the anterior ends of the ribs, providing medial extension. ...

. * A strong sheath, the

, encloses the carotid artery,

internal jugular vein The internal jugular vein is a paired jugular vein that collects blood from the brain and the superficial parts of the face and neck. This vein runs in the carotid sheath with the common carotid artery and vagus nerve. It begins in the poste ...

, and

vagus nerve The vagus nerve, also known as the tenth cranial nerve, cranial nerve X, or simply CN X, is a cranial nerve that interfaces with the parasympathetic control of the heart, lungs, and digestive tract. It comprises two nerves—the left and righ ...

. * The

extends medialward behind the carotid vessels, where it assists in forming their sheath, and passes in front of the prevertebral muscles. * The pretracheal fascia extends medially in front of the carotid vessels, and assists in forming the

References

External links

Sagittal Section Showing Deep Cervical Fascial Layers

* ttps://web.archive.org/web/20060515201222/http://iris3.med.tufts.edu/headneck/supr.htm Suprahyoid Cross-Section Showing Layers of Deep Cervical Fascia {{Portal bar, Anatomy Fascial spaces of the head and neck