COM Anatomy & Physiology of the Orofacial Complex 2 — Questions and Answers
Question 1: Which muscle is the primary elevator of the mandible during jaw closure?
- Masseter
- Medial pterygoid
- Temporalis
- All three contribute equally (Correct answer)
Correct answer: All three contribute equally
The masseter, medial pterygoid, and temporalis all contribute to mandibular elevation; no single muscle acts as the sole primary elevator.
Question 2: The hyoglossus muscle originates from the hyoid bone and its primary action is to:
- Protrude the tongue
- Depress and retract the tongue (Correct answer)
- Elevate the tongue tip
- Widen the tongue
Correct answer: Depress and retract the tongue
The hyoglossus depresses and retracts the tongue by pulling it downward and posteriorly.
Question 3: Which cranial nerve provides motor innervation to the muscles of mastication?
- CN VII (Facial nerve)
- CN V3 (Mandibular branch of trigeminal) (Correct answer)
- CN IX (Glossopharyngeal)
- CN XII (Hypoglossal)
Correct answer: CN V3 (Mandibular branch of trigeminal)
The mandibular branch (V3) of the trigeminal nerve provides motor innervation to all four muscles of mastication.
Question 4: The palatoglossus muscle is unique among tongue muscles because it is innervated by:
- CN XII (Hypoglossal)
- CN X (Vagus nerve) (Correct answer)
- CN V3 (Trigeminal)
- CN IX (Glossopharyngeal)
Correct answer: CN X (Vagus nerve)
Unlike all other tongue muscles innervated by CN XII, the palatoglossus is innervated by the vagus nerve (CN X) via the pharyngeal plexus.
Question 5: The Passavant's ridge is formed by contraction of which muscle during velopharyngeal closure?
- Superior pharyngeal constrictor (Correct answer)
- Palatopharyngeus
- Levator veli palatini
- Musculus uvulae
Correct answer: Superior pharyngeal constrictor
Passavant's ridge is a prominence formed by contraction of the superior pharyngeal constrictor, assisting velopharyngeal closure.
Question 6: Which salivary gland produces primarily serous secretions and drains via the parotid (Stensen's) duct?
- Submandibular gland
- Sublingual gland
- Parotid gland (Correct answer)
- Minor salivary glands
Correct answer: Parotid gland
The parotid gland is predominantly serous and its secretion drains through the parotid duct opposite the upper second molar.
Question 7: During nasal breathing, the turbinates (conchae) serve primarily to:
- Filter large particulates only
- Warm, humidify, and filter incoming air (Correct answer)
- Produce mucus for the sinuses
- Regulate olfactory sensitivity
Correct answer: Warm, humidify, and filter incoming air
The turbinates increase mucosal surface area to warm, humidify, and filter air before it reaches the lower airways.
COM Anatomy & Physiology of the Orofacial Complex 2
Which muscle is the primary elevator of the mandible during jaw closure?