Damage affecting the motor branch of the mandibular nerve results in paralysis of all listed muscles except ______________?
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Answer: C. Buccinator
Explanation
The buccinator muscle is a muscle of facial expression supplied by the facial nerve. Muscles of mastication are supplied by the motor branch of the mandibular nerve. Therefore, the buccinator is spared during mandibular nerve injuries. The mandibular nerve is the third division of the trigeminal nerve. It provides motor innervation to muscles used for chewing and jaw movement. Facial expression muscles are universally innervated by the facial nerve.
Damage to the mandibular nerve impairs chewing efficiency and jaw stability. Clinicians test jaw-closing strength to assess mandibular nerve motor function. Distinguishing motor nerve supplies is essential for diagnosing localized facial weakness. Option A medial pterygoid is a mastication muscle supplied by the mandibular nerve. Option B masseter is a primary chewing muscle innervated by the mandibular nerve. Option D anterior belly of digastric is innervated by the mandibular nerve branch.
Related questions
Q1. Motor and sensory innervation by the mandibular nerve is distributed to ________________?
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Answer: A. Anterior belly of digastric, mylohyoid , tensor tympani , tensor palati
The mandibular nerve supplies motor fibers to the mylohyoid and anterior digastric muscles. It also provides motor innervation to the tensor tympani and tensor veli palatini. These muscles all share a common embryonic or...
Q2. The maxillary artery arises as a collateral branch of______________?
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Answer: A. External carotid artery
The maxillary artery arises as one of the two major terminal branches of the external carotid artery. Internal carotid artery branches supply intracranial structures and the orbit without giving off facial branches. The...
Q3. The mental foramen is situated at which anatomical location_______________?
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Answer: A. Between roots of premolars
The mental foramen is situated on the external surface of the mandible. It is typically oriented inferior to the roots of the mandibular premolar teeth. This opening transmits the mental nerve and blood vessels supplying...
Q4. Origin attachments for the middle pharyngeal constrictor muscle are found at________________?
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Answer: A. Body of hyoid bone
The middle pharyngeal constrictor muscle originates from the hyoid bone structures. Its muscle fibers attach specifically to both the lesser and greater horns of hyoid. This origin allows the muscle to constrict the phar...
Q5. The primary arterial supply feeding the tonsil originates from_____________?
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Answer: A. Facial artery
The palatine tonsil receives its primary arterial blood supply directly from the tonsillar branch of the facial artery. Other nearby vessels contribute collateral blood flow, but the facial artery provides the dominant p...
Q6. The middle meningeal artery stems directly as a branch from_______________?
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Answer: B. Internal maxillary artery
The middle meningeal artery stems directly as a branch from the first part of the maxillary artery. It ascends through the infratemporal fossa to enter the cranial cavity through the foramen spinosum. This vessel provide...