Orofacial Anatomy & Physiology Flashcards

The orbicularis oris muscle is classified as which type of muscle?

Answer: Sphincter muscle

The orbicularis oris acts as a sphincter, encircling the mouth opening to compress and close the lips.

Which structure separates the oral cavity from the nasal cavity?

Answer: Both hard and soft palate

Both the hard palate (anterior bony portion) and soft palate (posterior muscular portion) together form the roof of the mouth and floor of the nasal cavity.

The hypoglossal nerve (CN XII) provides motor innervation to all tongue muscles EXCEPT which one?

Answer: Palatoglossus

The palatoglossus is innervated by the vagus nerve (CN X) via the pharyngeal plexus, making it the exception among tongue muscles.

In the context of orofacial myology, the 'nasolabial fold' is formed by which landmark?

Answer: Crease between cheek and upper lip

The nasolabial fold is the groove running from the sides of the nose to the corners of the mouth, formed where cheek tissue meets the upper lip.

Which muscle elevates the hyoid bone and assists in swallowing?

Answer: Mylohyoid

The mylohyoid elevates the hyoid bone and floor of the mouth, assisting in the oral and pharyngeal phases of swallowing.

The Stensen's duct (parotid duct) opens into the oral cavity opposite which tooth?

Answer: Upper second molar

Stensen's duct opens on the buccal mucosa of the cheek opposite the maxillary second molar.

Which anatomical structure marks the posterior boundary of the oral cavity?

Answer: Anterior tonsillar pillars

The anterior tonsillar pillars (palatoglossal arches) mark the transition between the oral cavity and the oropharynx.