system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Passavant's ridge is formed by -
assistant
The correct answer is  It is a mucosal ridge raised by fibres of palatopharyngeus.
It encircles the posterior and lateral walls of the nasopharyngeal isthmus.
Soft palate makes firm contact with this ridge to cut off nasopharynx from oropharynx during deglutition or speech. (Disease of ENT, P.L Dhingra)