This section is from the book "Applied Anatomy: The Construction Of The Human Body", by Gwilym G. Davis. Also available from Amazon: Applied anatomy: The construction of the human body.
There are two fascias in the neck, the superficial and the deep. The superficial fascia has blended with it anteriorly the platysma muscle and the termination of the nerves, arteries, and veins. The main trunks of these structures lie for all practical purposes beneath the superficial fascia and adherent to the surface of the deep fascia. It is for this reason that in raising the superficial structures the larger trunks remain applied to the deep fascia and are thus less liable to be injured in the living and mutilated in the dead. In the superficial fascia and on the deep fascia are the superficial lymphatics.
The superficial lymphatic nodes frequently suppurate. When they do the abscess so formed is prevented by the deep fascia from reaching the parts beneath, so the pus works its way out through the skin. As the superficial fascia is loose, if the abscess is slow in formation, it may extend for a considerable distance under the skin.
Sebaceous cysts are common in the neck. As they are superficial to the deep fascia, which is not involved, they can be removed without fear of wounding any important structures. The veins do not overlie them; they are always superficial to the veins, therefore there is no danger of wounding the external jugular.
The deep cervical fascia completely envelops the neck and sends its branches in between all it's various structures. It is the fibrous tissue that both unites and separates all the different structures to and from each other. Where this fascia is abundant it forms a distinct layer, but where it is scant it is simply a small amount of connective tissue between two adjacent parts.
Fig. 177. - Transverse section of the neck through the sixth cervical vertebra.
To follow all the processes of the deep fascia through the neck between its innumerable structures is impossible - nor is it necessary. The main reason for studying the deep cervical fascia and its various parts is to understand the course pursued by abscesses and infections. This is best done by limiting oneself to the main superficial layer and some of the larger layers crossing from side to side.
The principal layers of the deep cervical fascia are the superficial layer, which completely encircles and envelops the neck, the prevertebral layer, which passes from side to side in front of the spinal column, and the pretracheal layer, which passes from side to side in front of the trachea.
The superficial layer of the deep fascia envelops the whole of the neck, with the exception of the skin, platysma, and superficial fascia. It is attached above to the occipital protuberance, the superior curved line of the occiput, the mastoid process, then blends with the capsule of the parotid gland, then passes to the angle of the jaw and along the body of the mandible to the symphysis, whence it proceeds around the opposite side in the same manner. Below it is attached to the sternum, upper edge of the clavicle, acromion process, and spine of the scapula, thence across to the vertebral spines, to which and to the ligamentum nuchae it is attached up to the occipital protuberance. In the front of the neck it passes from the mandible down to be attached to the hyoid bone and thence downward to the sternum and clavicle.
From the under side of this superficial layer processes of fascia come off and envelop the various structures of the neck. Every separate structure of the neck is covered by it and therefore separated from the adjacent parts by a more or less distinct layer of the fascia. In many places it is quite thin or almost imperceptible, amounting to but a few shreds of fibrous tissue, in other places it is more distinct, forming more or less marked capsules, as in the case of the thyroid and submaxillary glands, or fibrous layers, as in the case of those in front of the vertebras and trachea. Posteriorly in the median line the superficial layer of the deep fascia sends a process which covers the under surface of the trapezius muscle. Anteriorly another process is given off to cover the under surface of the sternomastoid muscle. The superficial veins of the neck, the anterior, external, and posterior jugulars, lie on or in the deep fascia, being stuck to or blended with its upper surface.