NBDHE Test Head and Neck Anatomy 1 — Questions and Answers
Question 1: The submandibular gland's excretory duct (Wharton's duct) opens into the oral cavity at which structure?
- Parotid papilla opposite the upper second molar
- Sublingual caruncle at the base of the lingual frenum (Correct answer)
- Lateral wall of the oropharynx
- Soft palate adjacent to the uvula
Correct answer: Sublingual caruncle at the base of the lingual frenum
Wharton's duct travels anteriorly along the floor of the mouth and opens at the sublingual caruncle (a small papilla) on either side of the lingual frenum, near the midline of the floor of the mouth.
Question 2: The chorda tympani nerve, which travels with the lingual nerve, carries which type of information to the tongue?
- General somatic sensation from the posterior one-third of the tongue
- Motor innervation to the intrinsic muscles of the tongue
- Taste sensation from the anterior two-thirds of the tongue (Correct answer)
- Pain and temperature from the entire tongue
Correct answer: Taste sensation from the anterior two-thirds of the tongue
The chorda tympani is a branch of CN VII (facial nerve) that joins the lingual nerve (CN V3) in the infratemporal fossa. It conveys special sensory (taste) information from the anterior two-thirds of the tongue, while the lingual nerve itself provides general sensation to that same region.
Question 3: The infraorbital foramen is located on which bone and transmits which nerve?
- Zygomatic bone; zygomaticofacial nerve (CN V2)
- Maxilla; infraorbital nerve (CN V2) (Correct answer)
- Frontal bone; supraorbital nerve (CN V1)
- Mandible; mental nerve (CN V3)
Correct answer: Maxilla; infraorbital nerve (CN V2)
The infraorbital foramen is located on the anterior surface of the maxilla, approximately 1 cm below the inferior orbital rim. It transmits the infraorbital nerve (a terminal branch of the maxillary division, CN V2) along with the infraorbital artery and vein.
Question 4: Which cranial nerve provides motor innervation to the styloglossus muscle?
- Trigeminal nerve (CN V3)
- Facial nerve (CN VII)
- Glossopharyngeal nerve (CN IX)
- Hypoglossal nerve (CN XII) (Correct answer)
Correct answer: Hypoglossal nerve (CN XII)
The hypoglossal nerve (CN XII) innervates all intrinsic and extrinsic muscles of the tongue except the palatoglossus (innervated by CN X). The styloglossus, which retracts and elevates the tongue, is therefore innervated by CN XII.
Question 5: The submental lymph nodes serve as primary draining nodes for which structures?
- Parotid gland and upper lip
- Tip of the tongue and central lower lip (Correct answer)
- Posterior tongue and palatine tonsils
- Cheek mucosa and upper molars
Correct answer: Tip of the tongue and central lower lip
The submental lymph nodes, located in the submental triangle below the chin, receive primary lymphatic drainage from the tip of the tongue, midline floor of the mouth, the central portion of the lower lip, and the chin — making them clinically important in oral cancer surveillance.
Question 6: The buccinator muscle is innervated by which nerve?
- Buccal branch of the trigeminal nerve (CN V3) — motor
- Buccal branch of the facial nerve (CN VII) — motor (Correct answer)
- Mylohyoid nerve — motor
- Inferior alveolar nerve (CN V3) — motor
Correct answer: Buccal branch of the facial nerve (CN VII) — motor
Although the buccal branch of CN V3 provides sensory innervation to the cheek mucosa and skin, the buccinator muscle itself is a muscle of facial expression and is therefore innervated motorly by the buccal branch of the facial nerve (CN VII). This is a common source of confusion on dental board examinations.
NBDHE Test Head and Neck Anatomy 1
The submandibular gland's excretory duct (Wharton's duct) opens into the oral cavity at which structure?