Formation of the Palate

What forms the premaxilla or primitive palate carrying upper four incisor teeth?

What forms the rest of the palate?

What becomes ossified to form the hard palate?

What forms the soft palate?

What is the function of the frontonasal process?

What is the function of Passavant's muscle?

What is formed when the soft palate is elevated and comes in contact with Passavant's ridge?

Which fibres of the palatopharyngeus form a sphincter internal to the superior constrictor?

What is the name of the ridge formed on the posterior wall of the nasopharynx when Passavant's muscle contracts?

What is the passage that connects the nasopharynx to the oropharynx?

The premaxilla, which carries the upper four incisor teeth, is formed by the fusion of medial nasal folds from the frontonasal process.
The palatine processes of the maxilla and horizontal plates of the palatine bone form shelf-like structures that contribute to the formation of the palate.
Most of the palate undergoes ossification to form the hard palate.
The unossified posterior part of the fused palatal processes forms the soft palate.

Some upper fibres of the palatopharyngeus muscle pass circularly deep to the mucous membrane of the pharynx.
These fibres form a sphincter internal to the superior constrictor, known as Passavant's muscle.
When Passavant's muscle contracts, it raises a ridge called Passavant's ridge on the posterior wall of the nasopharynx.
The soft palate, when elevated, comes in contact with Passavant's ridge, closing the pharyngeal isthmus between the nasopharynx and the oropharynx.

The pharyngeal isthmus is a passage between the nasopharynx and the oropharynx.
Elevating the soft palate brings it in contact with Passavant's ridge, thereby closing the pharyngeal isthmus.