ADEX Head and Neck Anatomy 2 — Questions and Answers
Question 1: Which division of the trigeminal nerve passes through the foramen ovale?
- Ophthalmic division (V1)
- Maxillary division (V2)
- Mandibular division (V3) (Correct answer)
- Facial nerve (CN VII)
Correct answer: Mandibular division (V3)
The mandibular division (V3) of the trigeminal nerve exits the cranium through the foramen ovale in the greater wing of the sphenoid bone.
Question 2: The posterior superior alveolar (PSA) nerve typically innervates which maxillary teeth?
- All maxillary premolars and molars
- The second and third molars, plus the distobuccal and palatal roots of the first molar (Correct answer)
- All three maxillary molars including all roots of the first molar
- Only the maxillary second and third molars
Correct answer: The second and third molars, plus the distobuccal and palatal roots of the first molar
The PSA nerve innervates the maxillary second and third molars plus the distobuccal and palatal roots of the first molar; the mesiobuccal root is typically innervated by the middle superior alveolar (MSA) nerve.
Question 3: The buccinator muscle receives its motor innervation from which cranial nerve?
- Trigeminal nerve (CN V)
- Facial nerve (CN VII) (Correct answer)
- Glossopharyngeal nerve (CN IX)
- Hypoglossal nerve (CN XII)
Correct answer: Facial nerve (CN VII)
The buccinator is a muscle of facial expression and receives motor innervation from the buccal branch of the facial nerve (CN VII), like all muscles of facial expression.
Question 4: Which muscle forms the muscular floor of the oral cavity, creating a sling between the two sides of the mandible?
- Geniohyoid
- Digastric
- Mylohyoid (Correct answer)
- Stylohyoid
Correct answer: Mylohyoid
The mylohyoid muscle forms the primary muscular floor of the oral cavity, attaching along the mylohyoid line on the inner surface of the mandible and meeting at a median raphe.
Question 5: The mental nerve, providing sensation to the chin and lower lip, exits the mandible through which structure?
- Mandibular foramen
- Mental foramen (Correct answer)
- Incisive foramen
- Lingual foramen
Correct answer: Mental foramen
The mental nerve exits the mandible through the mental foramen, typically located below the apex of the mandibular second premolar, providing sensation to the chin and lower lip.
Question 6: Which muscle is primarily responsible for protruding the tongue and is innervated by the hypoglossal nerve?
- Styloglossus
- Palatoglossus
- Hyoglossus
- Genioglossus (Correct answer)
Correct answer: Genioglossus
The genioglossus is the primary tongue protruder, originating from the mental spine (genial tubercle) of the mandible and fanning out through the tongue.
Question 7: The lingual nerve provides general sensory innervation to which area?
- Posterior one-third of the tongue only
- Anterior two-thirds of the tongue and floor of the mouth (Correct answer)
- The entire tongue and floor of the mouth
- Posterior tongue and pharynx only
Correct answer: Anterior two-thirds of the tongue and floor of the mouth
The lingual nerve (a branch of V3) provides general sensation to the anterior two-thirds of the tongue and the floor of the mouth; the chorda tympani joins it to carry taste from the same region.
ADEX Head and Neck Anatomy 2
Which division of the trigeminal nerve passes through the foramen ovale?