Cloison sagittale
The cloison sagittale (sagittal partition), also known as Charpy fascia, is a sagittally oriented fascia on either side of the neck that separates the midline deep neck spaces (retropharyngeal space, prevertebral space, and danger space) from the more lateral parapharyngeal space (including carotid sheath). It extends from the posterolateral aspect of the pharynx (pharyngobasilar fascia, part of the middle layer of the deep cervical fascia) to the anterior tubercles of the transverse processes of the cervical vertebrae (where the deep layer of the deep cervical fascia attaches) . Thus, it is thought to be a part of either the middle or deep layer of the deep cervical fascia .