FASCIAL LAYERS OF THE NECK:
Netter Plate Number: 30

Fascial Layers of the neck:
Superficial or investing fascia:
Contains the platysma and muscles of facial expression.

Superficial layer of deep cervical fascia (red):
Contains the sternocleidomastoid and trapezius muscles in addition to the partoid and submandibular glands. This fascia spans the posterior triangle and splits anteriorly to create the suprasternal space of Burns.

Middle layer of deep cervical fascia (purple, blue):
The muscular layer contains the infrahyoid (strap) muscles, while the visceral layer contains the thyroid gland, pharynx, larynx, trachea and esophagus. The buccopharyngeal fascia (green) creates the posterior border of the middle fascial layer.

Deep layer of deep cervical fascia (orange):
Includes the Alar layer (posterior to middle visceral fascia,anterior to prevertebral fascia) and the prevertebral layer, investing the vertebral bodies and the deep muscles of the neck.
The Alar fascia is prevertebral fascia superiorly that delaminates, forming a separate layer that fuses inferiorly to the buccopharyngeal fascia at about the level of the cricoid cartilage.
Anterior to this layer is the retropharyngeal space, while posterior to this layer is the "Danger space", which extends into the mediastinum.
Please note, that this diagram is mislabeled, and the retropharyngeal space is ANTERIOR to the alar fascia.

Carotid sheath:
Contains the Carotid artery, Internal jugular vein and the vagus nerve.

*See neck infections.