New version: FreeMedicalMCQs.com (Click Here)

Prepare for your medical exam, USMLE, MCCEE with a FREE MCQs and clinical cases! ECG, CXR and all types of free medical MCQs with answers, good luck! Medical MCQs from students to students.
A 34-year-old man injures his lateral pterygoid muscle. Which of the following activities will be adversely affected by this injury?
(A) Closing the jaw
(B) Smiling
(C) Swallowing
(D) Whistling
(E) Yawning
in Anatomy by

1 Answer

0 votes
 
Best answer
(E) Yawning
The muscles involved in jaw movement are fourfold: lateral pterygoid, masseter, temporalis, and medial pterygoid. The lateral pterygoid opens the jaw while the other three close the jaw. All four are innervated by the trigeminal nerve (V3). One can remember this with the mnemonic “M’s Munch” and “Lateral Lowers.” Yawning would be impaired with a lateral pterygoid injury.

Answer A is incorrect. Closing the mouth is performed by the masseter, temporalis, and medial pterygoid.
Answer B is incorrect. Smiling requires the function of many facial muscles, including the zygomaticus major.
Answer C is incorrect. Swallowing is mediated by the pharynx and the tongue.
Answer D is incorrect. Whistling is mediated by the tongue and facial muscles, such as the buccinator and orbicularis oris.
by
...