Pharyngobasilar fascia

The pharyngobasilar fascia is a dense fibroelastic layer of the pharyngeal wall situated between the mucosa/submucosa internally and the pharyngeal muscles externally. It forms part of the fibrous framework of the pharynx and provides structural support, particularly in the upper part of the pharynx where the muscular wall is incomplete, thus specifically contributing to the structural integrity of the nasopharynx.

Superiorly, the pharyngeal constrictor muscles do not fully reach the base of the skull. In this region, the pharyngobasilar fascia compensates for the muscular deficiency by strengthening and suspending the pharyngeal wall. It is therefore most prominent in the nasopharyngeal region and gradually becomes thinner inferiorly as the muscular coat becomes more complete.

Attachment of pharyngobasial fascia

The pharyngobasilar fascia is attached superiorly to several structures at the base of the skull, including the pharyngeal tubercle of the occipital bone, the petrous part of the temporal bone, the cartilage of the auditory tube, and the posterior border of the medial pterygoid plate.

Inferiorly, it blends with the connective tissue between the mucosa and the muscular wall of the pharynx.

Distinction between pharyngobasilar fascia and submucosa of pharynx

Structurally, the pharyngobasilar fascia is regarded as a specialised thickening or condensation of the pharyngeal submucosal connective tissue. While the submucosa is a loose connective tissue layer containing glands, vessels, lymphatics, and nerves, the pharyngobasilar fascia represents its dense supporting component.

Note: important relations

Structures such as the levator veli palatini muscle, and the cartilaginous part of auditory tube, they pass through the pharyngobasial fascia, abve the superior contrictor muscle of pharynx, to reach the soft palate and enter the lateral wall of nasopharynx, respectively.