NBDHE Head and Neck Anatomy Questions and Answers

Question 1

A patient is asked to protrude their mandible forward. Which muscle is the PRIMARY agonist for this action?

Accepted Answer

Lateral pterygoid muscle

Answer

The lateral pterygoid muscle, particularly when both sides contract together, is the primary muscle responsible for protruding the mandible. The temporalis muscle primarily elevates and retracts the mandible, the masseter is a powerful elevator, and the medial pterygoid assists with elevation and side-to-side movements.

Question 2

A patient presents with a painful swelling on the floor of the mouth, inferior to the tongue, which worsens just before and during meals. A blockage of which structure is the MOST likely cause of these symptoms?

Accepted Answer

Wharton's duct

Answer

Wharton's duct is the main excretory duct for the submandibular salivary gland. A blockage, often by a sialolith (salivary stone), causes saliva to back up, leading to painful swelling in the floor of the mouth that is exacerbated by the increased saliva production associated with eating. Stensen's duct serves the parotid gland, while Bartholin's and Rivinus ducts serve the sublingual gland.

Question 3

During a mandibular block injection, a patient experiences immediate numbness of the lower lip and chin on the injected side. This indicates the anesthetic has effectively reached which terminal nerve branch?

Accepted Answer

Mental nerve

Answer

The mental nerve is a terminal branch of the inferior alveolar nerve (which is the target of a mandibular block). It exits the mandible through the mental foramen to provide sensory innervation to the skin of the chin and lower lip. Numbness in this area is a classic sign of a successful inferior alveolar nerve block.

Question 4

An infection originating from a mandibular first molar would MOST likely cause initial tenderness and enlargement in which group of lymph nodes?

Accepted Answer

Submandibular nodes

Answer

The submandibular lymph nodes are the primary drainage site for all mandibular posterior teeth, including the first molar. The submental nodes drain the mandibular incisors and the tip of the tongue. The deep cervical nodes receive drainage from the submandibular nodes later, and the parotid nodes drain the scalp, ear, and parotid gland.

Question 5

Which of the following structures passes through the foramen ovale of the sphenoid bone?

Accepted Answer

Mandibular division of the trigeminal nerve (V3)

Answer

The mandibular division of the trigeminal nerve (V3) exits the skull through the foramen ovale. The maxillary division (V2) passes through the foramen rotundum, the ophthalmic division (V1) passes through the superior orbital fissure, and the middle meningeal artery passes through the foramen spinosum.

NBDHE Test Practice Test

NBDHE Test Practice Test

NBDHE Head and Neck Anatomy Questions and Answers