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Flashcards in Gray's - Head & Neck - Kate Deck (69)
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1
Q

A 46-year-old woman is admitted to the hospital
with a large mass in her lower anterior neck. Ultrasonic
examination reveals a benign tumor of her thyroid
gland. During the procedure to remove the tumor the
superior thyroid artery is identifi ed and used as a landmark
in order not to damage its small companion
nerve. Which of the following nerves is most likely to accompany the superior thyroid artery?

A. Cervical sympathetic trunk
B. External branch of the superior laryngeal
C. Inferior root of the ansa cervicalis
D. Internal branch of the superior laryngeal
E. Recurrent laryngeal

A

B. The external branch of the superior laryngeal

nerve courses together with the superior thyroid artery for much of its route.

2
Q

A 3-year-old girl ruptured her eardrum when she
inserted a pencil into her external ear canal. She was urgently admitted to the emergency department. Physical examination revealed pain in her ear and a few drops of blood in the external auditory meatus. There was the concern that there might possibly have been an injury to the nerve that principally innervates the external surface of the tympanic membrane. Which of the following tests is most likely to be performed during physical examination to check for injury to this nerve?

A. Check the taste in the anterior two thirds of
the tongue.
B. Check the sensation to the pharynx and
palate.
C. Check if there is paraesthesia at the TMJ.
D. Check for sensation in the larynx.
E. Check for sensation in the nasal cavity.

A

C. The external surface of the tympanic membrane
is innervated primarily by the auriculotemporal
nerve, a branch of the mandibular division of the trigeminal nerve. Damage to this nerve would additionally result in painful movements of the TMJ because this joint receives innervation from the same nerve.

3
Q

A 27-year-old woman is admitted to the emergency
department after she was thrown from a motor
scooter. Radiographic evaluation reveals a type I Lefort fracture and comminuted fracture of the mandible and TMJ. Despite reconstructive surgery, the patient develops hyperacusis (sensitivity to loud sounds) due to facial nerve paralysis. Which of the following muscles is most likely paralyzed?

 A. Posterior belly of digastric
 B. Stapedius
 C. Tensor tympani
 D. Stylohyoid
 E. Cricothyroid
A

B. Both the stapedius and tensor tympani normally
function to dampen movements of the middle
ear ossicles, thereby muting sound and preventing
hyperacusis. The stapedius would be the source of
hyperacusis in this problem because it receives its
innervation from the facial nerve. The tensor tympani
receives motor innervation from the mandibular
division of the trigeminal nerve.

4
Q

A 43-year-old man is admitted to the emergency
department with a fracture of the base of his skull. A thorough physical examination reveals that a number of structures have been injured, possibly including the right greater petrosal nerve. Which of the following conditions needs to be identified during physical examination to confirm the diagnosis of greater petrosal nerve injury?

A. Partial dryness of the mouth due to lack of
salivary secretions from the submandibular
and sublingual glands
B. Partial dryness of the mouth due to lack of
salivry secretions from the parotid gland
C. Dryness of the right cornea due to lack of lacrimal secretion
D. Loss of taste sensation from the right anterior
two thirds of the tongue
E. Loss of gener l sensation from the right anterior
two thirds of the tongue

A

C. The greater petrosal nerve carries parasympathetic fibers that are involved in the innervation of the lacrimal gland, as well as the mucosal glands of the nose, palate, and pharynx. As a result, an injury to the right greater petrosal nerve would be expected to result in decreased lacrimal secretions for the right eye.

5
Q

A 12 year old girl is admitted to the emergency
department with a middle ear infection. Physical examination reveals a long history of chronic middle ear infections that have produced a lesion in the tympanic plexus in the middle ear cavity. Since the preganglionic parasympathetic fibers that pass through the plexus have been lost, which of the following conditions will be detectable during physical examination?

A. Diminished mucus in the nasal cavity
B. Diminished mucus on the soft palate
C. Diminished saliva production by the parotid
gland
D. Diminished saliva production by the submandibular and sublingual glands
E. Diminished tear production by the lacrimal
gland

A

C. Parasympathetic innervation of the parotid
gland is provided by axons carried by the glossopharyngeal nerve that emerge from the tympanic plexus of the middle ear as the lesser petrosal nerve. These preganglionic parasympathetic fibers terminate by synapses in the otic ganglion, which supplies the secretory
parasympathetic innervation to the parotid gland.

6
Q

A 38-year-old patient is admitted to the dental
clinic with acute dental pain. The attending dentist
found penetrating dental caries (tooth decay) affecting one of the mandibular molar teeth. Which of the following nerves would the dentist need to anesthetize to remove the caries in that tooth?

A. Lingual
B. Inferior alveolar
C. Buccal
D. Mental
E. Mylohyoid
A

B. The inferior alveolar branch of the mandibular
division of the trigeminal nerve provides sensory innervation to the mandibular teeth and would require anesthesia to abolish painful sensation.

7
Q

A 59-year-old man is admitted to the emergency
department with acute pain on his mandible. An MRI examination reveals an acute inflammation of the TMJ due to arthritis. Which of the following muscles will most likely be affected by the inflammatory process of the TMJ?

A. Temporalis
B. Medial pterygoid
C. Masseter
D. Lateral pterygoid
E. Buccinator
A

D. Part of the lateral pterygoid muscle has its
insertion on the articular disk within the TMJ and
would be most affected by the inflammation of this joint.

8
Q

A 56-year-old female complains of diplopia (double
vision) when walking down stairs. A lesion of
which of the following nerves is most likely responsible for this patient’s complaint?

A. Optic
B. Oculomotor
C. Abducens
D. Trochlear
E. Frontal
A

D. The trochlear nerve innervates the superior
oblique muscle, which acts to move the pupil downward and laterally. It is the only muscle that can depress the pupil when the eye is adducted When an individual walks down stairs, this eye motion is initiated, and diplopia results if it is not functioning properly

9
Q

A 43-year-old male is admitted to the hospital
complaining of diplopia (double vision) when walking
down stairs. During physical examination of the extraocular muscles the patient experiences diplopia, and when he is asked to turn his right eye inward toward his nose and look down, he is able to look inward but not down. Which nerve is most likely involved?

A. Abducens
B. Nasociliary
C. Oculomotor, inferior division
D. Oculomotor, superior division
E. Trochlear
A

E. The superior oblique muscle turns the pupil
downward from the adducted position. Inability to
perform this motion, in conjunction with diplopia
when walking down stairs, indicates damage to the
trochlear nerve.

10
Q

A 44-year-old patient is admitted to the hospital
with Raynaud’s disease. A sympathetic blocking drug is administered in high doses. Which of the following conditions will be expected to occur as an adverse effect of the drug?

A. Exophthalmos and dilated pupil
B. Enophthalmos and dry eye
C. Dry eye and inability to accommodate for
reading
D. Wide-open eyelids and loss of depth perception
E. Ptosis and miosis

A

E. Ptosis and miosis occur in response to blocking
of sympathetic innervation. Ptosis (drooping of
the eyelid) results from lack of innervation of the
superior tarsal muscle (of Müller), and miosis (pupillary constriction) results from unopposed parasympathetic innervation of the pupil.

11
Q

A 47-year-old woman is admitted to the hospital
with signs of cavernous sinus thrombosis. Radiographic examination reveals a pituitary tumor involving the cavernous sinus, confirming the initial diagnosis ( Fig 7-3 ). During physical examination it is suspected that the right abducens nerve of the patient has been damaged by the tumor. In which direction will the physician most likely ask the patient to turn her right eye to confirm the abducens nerve damage, assuming she is unable to perform this task?

A. Inward
B. Outward
C. Downward
D. Down and out
E. Down and in
A

B. The right abducens nerve innervates the right
lateral rectus, which mediates outward movement
(abduction) of the right eye.

12
Q

An 8-year-old male is admitted to the hospital
with a drooping right eyelid (ptosis). The initial diagnosis is Horner’s syndrome ( Fig. 7-4 ). Which of the following additional signs on the right side would confirm the diagnosis?

A. Constricted pupil
B. Dry eye
C. Exophthalmos
D. Pale, blanched face
E. Sweaty face
A

A. Horner’s syndrome involves inte ruption of
sympathetic supply to the face This results in ptosis
(drooping eyelid) miosis (constricted pupil), and anhydrosis (lack of sweating) of the face

13
Q

A 32-year-old woman is admitted to the hospital
with headaches and dizziness. During physical examination it is noted that the patient has partial ptosis (drooping eyelid). Which of the following muscles is most likely paralyzed?

A. Orbicularis oculi, lacrimal part
B. Orbicularis oculi, palpebral part
C. Levator palpebrae superioris
D. Superior oblique
E. Superior tarsal (of Müller)
A

E. The superior tarsal muscle (of Müller), innervated
by sympathetics, assists in elevating the eyelids
and holding them up. Damage would result in partial
ptosis of the eyelid.

14
Q

A 16-year-old boy is admitted to the hospital with
fever, confused mental state, and drowsiness. During physical examination it is noted that the boy suffers from severe acne. Radiologic examination reveals cavernous sinus thrombosis. Which of the following routes of entry to the cavernous sinus would most likely be responsible for the infection and thrombosis?

A. Carotid artery
B. Mastoid emissary vein
C. Middle meningeal artery
D. Ophthalmic vein
E. Parietal emissary vein
A

D. Cavernous sinus thrombosis can often result
from squeezing pimples or other infectious processes located around the danger area of the face, which includes the area of the face directly surrounding the nose. This physical pressure has the potential to move infectious agents from the pimple into the ophthalmic vein, which then carries i to the cavernous sinus.

The pterygoid venous lexus and ophthalmic vein both communicate with the cavernous sinus and therefore offer a route of travel for the spread of infection, but the path provided by the superior ophthalmic vein is a more direct route. Additionally, the superior ophthalmic vein receives blood supply from the supraorbital supratrochlear, and angular veins that supply the area around the nose and lower forehead. (Venous blood in the head can flow in either direction because these veins do not possess valves.)

15
Q

A 68-year-old man is admitted to the emergency
department after an acute cerebral vascular accident (stroke). Radiographic studies reveal that the primary damage was to the anterior inferior cerebellar artery, resulting in a small hemorrhage of the artery at its origin from the main trunk. Which of the following nerves will most likely be immediately affected by the hemorrhage?

A. Optic nerve
B. Oculomotor nerve
C. Trochlear nerve
D. Trigeminal nerve
E. Abducens nerve
A

E. The anterior inferior cerebellar artery (AICA)
is a major supplier of the anterior inferior portion of
the cerebellum. Nerves located in close proximity
would likely be affected by hemorrhage of this artery.The abducens nerve is situated at the pontomedullary junction and is therefore most likely to be damaged following
hemorrhage of the AICA.

16
Q

A 5-year-old boy is admitted to the hospital with
otitis media. Otoscopic examination reveals a bulging and inflamed eardrum. It is decided to incise the tympanic membrane to relieve the painful pressure and allow drainage of the infection associated with otitis media. Which of the following is the best location to make an opening (myringotomy) for drainage?

A. The anterior superior quadrant of the eardrum
B. The posterior superior quadrant of the eardrum
C. Directly through the site of the umbo
D. The posterior inferior quadrant of the eardrum
E. A vertical incision should be made in the
eardrum, from the 12 o’clock position of the
rim of the eardrum to the 6 o’clock position
of the rim.

A

D. The posterior inferior quadrant of the eardrum
is the only portion of the tympanic membrane that
would allow for an incision with minimal or no damage to adjacent important structures.

17
Q

A 56-year-old man is diagnosed with an extradural
tumor in the posterior cranial fossa. When the patient protruded his tongue during physical examination, the tongue deviated to the right. Which of the following muscles and nerves are most likely injured?

A. Right hypoglossal nerve and right genioglossus
B. Left hypoglossal nerve and left genioglossus
C. Right hyoglossus and left styloglossus
D. Right geniohyoid and fi rst cervical nerve
E. Contralateral vagus and hypoglossal nerves

A

A. The hypoglossal nerve innervates the muscles
of the tongue and is therefore directly involved
in alteration of shape and movement of the tongue
A lesion in this nerve would cause deviation of the
tongue toward the injured side, which could be observed upon protrusion of the tongue.

18
Q

A 62-year old man is admitted to the hospital
with blurred vision. Physical examination reveals a
long history of gradual loss of his visual field. The intraocular pressure is high, and a diagnosis of glaucomais made. Which of the following spaces first receives the aqueous humor secreted by the epithelium of the ciliary body?

A. Anterior chamber
B. Posterior chamber
C. Pupil
D. Vitreous
E. Lacrimal sac
A

B. The posterior chamber receives ciliary body
secretions first. The ciliary body produces aqueous
humor and is located in the posterior chamber. Increased production of fluid from this site would
cause an increase in intraocular pressure if drainage is inadequate. The iridoscleral angle of the anterior chamber is the location of drainage of the aqueous humor; therefore, a blockage of drainage in this location can cause increased intraocular pressure.

19
Q

A 17-year-old woman is admitted to the hospital
with tonsillitis. A tonsillectomy is performed and the
patient complains postoperatively of ear pain. Which
of the following nerves was most likely injured during
the surgical procedure?

A. Auriculotemporal
B. Lesser petrosal
C. Vagus
D. Glossopharyngeal
E. Chorda tympani
A

D. The glossopharyngeal nerve mediates general
somatic sensation from the pharynx, the auditory
tube, and from the middle ear. Painful sensations
from the pharynx, including the auditory tube, can be referred to the ear by this nerve, as in this case of tonsillectomy.

20
Q

A 49-year old woman is admitted to the hospital
with headaches and dizziness. Radiographic examination reveals a tumor in the jugular canal. Upon physical examination, when the right side of the pharyngeal wall is touched with a tongue depressor, the uvula deviates to he left and the left pharyngeal wall contracts upward. When the left pharyngeal wall is touched, the response is similar. Which of the following nerves is most likely to have been injured by the tumor?

A. Right glossopharyngeal
B. Left glossopharyngeal
C. Right mandibular
D. Left hypoglossal
E. Right vagus
A

E. A tumor of the jugular canal would likely affect
the glossopharyngeal, vagus, and accessory
nerves as they exit the cranium through the jugular
foramen. The uvula deviates toward the unaffected
side of the pharyngeal muscles because of the pull of the unopposed levator veli palatini. In this case, the uvula deviates to the left, indicating that the left
palatal muscles are unaffected whereas the right
muscles are not working properly. The pharyngeal
wall on the left side is also drawn upward by the
nonparalyzed stylopharyngeus, supplied by the left
glossopharyngeal nerve. The pharyngeal constrictor
muscles, as well as muscles of the palate, are all innervated by the vagus nerve, except for the tensor
veli palatini, which is supplied by the trigeminal
nerve.

21
Q

A 45-year-old man is admitted to the emergency
department with severe dyspnea. During physical examination there is swelling in the floor of his mouth and pharynx so that his airway is nearly totally occluded. In addition, there is a swelling in his lower jaw and upper neck. His physical history indicates that one of his lower molars was extracted a week ago and he had been feeling worse every day since that event. Which of the following conditions will be the most likely diagnosis?

A. Quinsy
B. Torus palatinus
C. Ankyloglossia
D. Ranula
E. Ludwig’s angina
A

E. An infection of the submandibular space is
usually the result of a dental infection in the mandibular molar area in the floor of the mouth (Ludwig’s angina). If the patient is not treated with antibiotics promptly, the pharyngeal and submandibular swelling can lead to asphyxiation.

22
Q

A 5-year-old girl is admitted to the hospital with
an upper respiratory tract infection. During physical
examination her sense of hearing appears to be poor. Her right ear is painful, and upon otoscopic examination a golden brown fluid can be observed through the tympanic membrane. Which is the most likely direct route for the spread of an infection from the upper respiratory
tract to the middle ear cavity?

A. Pharyngotympanic tube
B. Choanae
C. Nostrils
D. Facial canal
E. Internal acoustic meatus
A

A. The auditory (eustachian or pharyngotympanic)
tube is a mucosal-lined tube that provides a direct
connection from the nasopharynx to the middle
ear cavity. A respiratory infection can travel from the
upper respiratory tract to the oropharynx or nasopharynx and then on into the middle ear via the auditory tube.

23
Q

A 54-year-old man is admitted to the hospital
with severe pain in his nasal cavity. Radiographic examination reveals a carcinoma in his nasal cavity. In which of the following locations would the carcinoma block the hiatus of the maxillary sinus?

A. Inferior meatus
B. Middle meatus
C. Superior meatus
D. Nasopharynx
E. Sphenoethmoidal recess
A

B. The maxillary sinus drains via the middle
meatus, specifically via the semilunar hiatus. The
middle meatus and semilunar hiatus are ocated under the middle nasal concha

24
Q

A 54-year-old male is diagnosed with an aneurysm of the basilar artery close to the cavernous sinus
An anterior approach to the sella turcica through the
nasal cavity is performed. Through which of the following routes is the surgeon most likely to enter the cranial cavity?

A. Cribriform plate
B. Cavernous sinus
C. Frontal sinus
D. Maxillary sinus
E. Sphenoidal sinus
A

E. The sphenoidal sinus provides the most direct

access to the pituitary gland, which is situated directly above this sinus.

25
Q

A 10-year-old girl is admitted to the hospital with
tonsillitis. A tonsillectomy is performed and the tonsils are removed On physical examination one week later the patient has absence of the gag reflex on the left when the posterior part of the tongue is depressed. The sensory portion of which of the following nerves was most likely injured?

A. Facial
B. Glossopharyngeal
C. Mandibular
D Maxillary
E. Hypoglossal
A

B. The gag reflex is composed of both an afferent
and an efferent limb. These reflexes are mediated
by the glossopharyngeal and vagus nerves, respectively. Together, the glossopharyngeal and vagus nerves are responsible for the contraction of the muscles of the pharynx involved in the gag reflex. In this case the glossopharyngeal nerve was injured when the tonsils were excised, resulting in the loss of the sensory side of the reflex.

26
Q

A 56-year-old woman has just undergone a complete thyroidectomy. After she recovers from the anesthesia a hoarseness of her voice is noted that persists for 3 weeks. Subsequent examination shows a permanently adducted vocal fold on the right side. Surgical trauma to the innervation of which of the following muscles is most likely to be responsible for the position of the right vocal fold?

A. Aryepiglottic
B. Posterior cricoarytenoid
C. Thyroarytenoid
D. Transverse arytenoids
E. Vocalis
A

B The recurrent laryngeal nerve is often at risk
of being damaged during a thyroidectomy. Patients
who have a transected or damaged recurrent laryngeal will often present with a characteristic hoarseness following surgery. The posterior cricoarytenoid is supplied by the recurrent laryngeal and would thus be impaired following damage to the nerve. The posterior cricoarytenoid is the only muscle responsible for abduction of the vocal cords, and paralysis of this muscle would result in a permanently adducted position of the involved vocal cord.

27
Q

A 45-year-old man with a complaint of ear pain
and difficulty hearing is diagnosed with tonsillitis. Otoscopic examination reveals fluid in the middle ear cavity. Hypertrophy of which of the following structures would be most likely to compromise the drainage of the auditory tube?

A. Lingual tonsil
B. Palatine tonsil
C. Pharyngeal tonsil
D. Superior constrictor muscle
E. Uvula
A

C. The pharyngeal tonsil is situated in a slitlike
space, the pharyngeal recess, in the nasopharynx
behind the opening of the auditory (eustachian)
tube, and a pharyngeal tonsil in this location can
lead to blockage of the drainage of the auditory tube.

28
Q

While at summer camp, a 10-year-old boy develops
severe pharyngitis and swollen tonsils. Infection
may spread from the nasopharynx to the middle ear
cavity along the derivative of which embryonic pharyngeal pouch?

A First
B. Second
C. Third
D. Fourth
E. Sixth
A

A. Infection can spread from the nasopharynx to
the middle ear by way of the auditory tube, which
opens to both spaces. The first pharyngeal pouch is
responsible for formation both of the auditory tube
and middle ear cavity

29
Q

You wake one morning to discover that your
alarm has not worked and you are running late. Desperate to get to your biochemistry lecture in time, yet unbearably hungry, you quickly throw some bread in the toaster as you get ready. Despite the toast burning a little, you eat it quickly as you rush out the door. The burnt parts of the toast scratch the roof of your mouth, leaving you with a stinging sensation there. What nerve is collecting this sensation from the hard palate?

A. Posterior superior alveolar nerve
B. Inferior alveolar nerve
C. Lingual nerve
D. Greater palatine nerve
E. Lesser palatine nerve
A

D. The greater palatine nerve is responsible for

innervation of the hard palate, or the hard part of the roof of the mouth.

30
Q

A 32-year-old woman underwent a thyroidectomy.
Two months postoperatively, it was observed that the patient had lost the ability to notice the presence of foreign objects in the laryngeal vestibule. Which of the following nerves was most likely injured?

A. Internal laryngeal nerve
B. External laryngeal nerve
C. Glossopharyngeal nerve
D. Hypoglossal nerve
E. Recurrent laryngeal nerve
A

A. Damage to the internal laryngeal nerve would
result in a general loss of sensation to the larynx
above the vocal cords, leaving the patient with an inability to detect food or foreign objects in the laryngeal vestibule The external laryngeal nerve and recurrent laryngeal nerve are both at risk during thyroidectomy.

31
Q

A 4-year-old boy suffering from ankyloglossia is
brought to the speech therapist. The examining physician recommends that the child be admitted for operation by a pediatric surgeon. Which of the following surgical procedures would be most appropriate for this condition?

A. Removal of pterygomandibular raphe
B. Resection of the pterygoid hamulus bilaterally
C. Cutting the lingual frenulum
D. Repair of the palate
E. Removal of the central segment of the hyoid
bone

A

C. Ankyloglossia (tongue-tie) is characterized by
a lingual frenulum that extends all the way to the tip
of the tongue. This condition can cause problems
with speech, feeding, and oral hygiene as a result of
the low range of motion of the tongue. Ankyloglossia
can be treated surgically by cutting the lingual frenulum.

32
Q

An 8-year-old boy was suffering from a severe
infection of the right middle ear. Within the course of
a week, the infection had spread to the mastoid antrum and the mastoid air cells. The organisms did not respond to antibiotics, so the surgeon decided to perform a radical mastoid operation. Following the operation, it was noticed that the boy’s face was distorted. The mouth was drawn upward to the left and he was unable to close his right eye. Saliva tended to accumulate in his right cheek and dribble f om the corner of his mouth. What structure was most l kely damaged during the operation?

 A. Mandibular nerve
B. Parotid duct
C. Vagus nerve
D. Facial nerve
E. Glossopharyngeal nerve
A

D. Of the answer choices listed, the left facial
nerve of the patient is the most likely to be damaged
during the mastoidectomy. The facial nerve exits the
skull via the stylomastoid foramen, just anterior to
the mastoid process. A lesion of the facial nerve is
likely to cause the symptoms described as a result of paralysis of the facial muscles.

33
Q

An 8 year old boy had an extensive mastoidectomy
due to an infection that did not respond to antibiotics. Postoperatively he had Bell’s palsy (facial paralysis), and one of the features was that saliva tended to accumulate in the vestibule of his oral cavity and dribble from the corner of his mouth. Which of the following muscles was paralyzed to allow this condition to occur?

 A. Zygomoaticus major
B. Orbicularis oculi
C. Buccinator
D. Levator palpebrae superioris
E. Orbicularis oris
A

C. Normally the tonus of the buccinator muscle
prevents the accumulation of saliva and foodstuffs
in the oral vestibule. Although a lesion of the
facial nerve would paralyze the other muscles listed,
the buccinator is the most important muscle of the
cheek.

34
Q

A 32-year-old man is admitted to the emergency
department with visual problems. Radiographic examination reveals a tumor of the adenohypophysis (anterior pituitary gland). Physical examination reveals a loss of the lateral halves of the fields of vision of both eyes (bitemporal hemianopia or “tunnel vision”). Which of the following structures was most likely compressed
by the tumor?

 A. Optic nerve
B. Optic chiasm
C. Optic tract
D. Oculomotor
E. Abducens nerve
A

B. Compression of the optic chiasm can cause
bitemporal hemianopia due to compression of nerve
fi bers coming from the nasal hemiretinas of both
eyes. The optic chiasm is located in very close proximity above the pituitary gland.

35
Q

A 45-year-old female is admitted to the emergency
department with visual problems when she walks down stairs. During physical examination the patient exhibits weakness of her downward medial gaze. Cerebral arteriography and CT images indicate that a nerve is being compressed by an arterial aneurysm just inferior to the tentorium cerebelli Which of the following arteries and nerves is most likely being compressed?

A. Internal carotid artery/abducens nerve
B. Middle cerebral artery/oculomotor nerve
C Posterior cerebral artery/ophthalmic nerve
D Basilar artery/ophthalmic nerve
E Superior cerebellar artery/trochlear nerve

A

E. A lesion of the trochlear nerve causes weakness
of downward medial gaze. As a result, patients
with trochlear nerve lesions commonly have difficulty
walking down stairs. The superior cerebellar artery
branches from the basilar artery just before it bifurcates into the posterior cerebral arteries. The trochlear nerve emerges from the dorsal aspect of the midbrain and can easily be compressed by an aneurysm of the superior cerebellar artery as it wraps around the midbrain.

36
Q

A 72-year-old woman is admitted to the emergency
department with tenderness in the upper right
thorax, painful to compression. During physical examination the patient presents with slight ptosis of her right eye. The right pupil is constricted more distinctly than the contralateral pupil. Which of the following is the most likely diagnosis?

 A. Raynaud’s disease
B. Frey syndrome
C. Bell palsy
D. Quinsy
E. Pancoast tumor
A

E. A Pancoast tumor is located in the pulmonary
apex, usually in the right lung.These tumors can
involve the sympathetic chain ganglia and cause
Horner’s syndrome (slight ptosis and miosis).

37
Q

A 32-year-old man is admitted to the hospital
with severe headache and visual problems. The dilator pupillae muscle, the smooth muscle cell fibers of the superior tarsal muscle (of Müller, part of the levator palpebrae superioris), and the smooth muscle cells of the blood vessels of the ciliary body are supplied by efferent nerve firbers. Which of the following structures contains the neural cell bodies of these firbers?

 A. Pterygopalatine ganglion
B. IML (lateral horn) C1 to C4
C. Geniculate ganglion
D. Nucleus solitarius
E. Superior cervical ganglion
A

E. The dilator pupillae, levator palpebrae superioris,
and smooth muscle cells of blood vessels in the
ciliary body all receive sympathetic innervation. The
postsynaptic cell bodies of the sympathetic neurons
that innervate these structures are located in the superior cervical ganglion

38
Q

A 22-year-old male is admitted to the hospital
after he was hit in the right eye with a frozen fi sh,
thrown playfully by a friend while they were passing
through the seafood section of the market. During
physical examination considerable swelling and discoloration of the eyelids was observed. In addition, the patient could not turn his pupil laterally from forward gaze, indicating probable muscle entrapment. Which of the following bones was most likely fractured?

 A. Orbital plate of the frontal bone
B. Lamina papyracea of the ethmoid bone
C. Orbital plate of the maxilla
D. Cribriform plate of the ethmoid bone
E. Greater wing of the sphenoid bone
A

B. A fracture of the lamina papyracea of the
ethmoid bone is likely to entrap the medial rectus
muscle, causing an inability to gaze laterally.

39
Q

A 57-year-old man is admitted to the emergency
department with dizziness and severe headaches. A CT scan evaluation reveals a tumor in the superior orbital fissure. Upon physical examination the patient’s eye ball is fixed in an abducted position, slightly depressed, and the pupil is dilated. In addition, the superior palpebrae are ptotic. When the patient is asked to move the pupil toward the nose, the pupil rotates medially. Consensual corneal reflexes are normal. Which of the following nerves is most likely affected?

A. Trochlear nerve
B. Oculomotor nerve
C. Abducens nerve and sympathetic nerve
plexus accompanying the ophthalmic artery
D. Ophthalmic nerve and short ciliary nerve
E. Superior division of oculomotor nerve and the nasociliary nerve

A

B. A lesion of the oculomotor nerve will cause
the eye to remain in a “down and out” position. This
is due to the actions of the unopposed lateral rectus
(supplied by the abducens nerve) and the superior
oblique (supplied by the trochlear nerve).

40
Q

An unconscious 57 year-old man is transported
to the emergency department after falling from a tree. A CT scan evaluation reveals a fracture of the cribriform plate ( Fig 7-5 ). Which of the following conditions will most likely be present during the physical examination?

A Entrapment of the eyeball
B. Anosmia
C. Hyperacusis
D. Tinnitus
E. Deafness
A

B. The axons of olfactory nerves run directly
through the cribriform plate to synapse in the olfactory bulb Damage to this plate can damage the nerve
axons, causing anosmia (loss of the sense of smell).

41
Q

A 45-year-old woman is admitted to the hospital
with a swelling on the side of her face of 2 months’
duration. Radiographic examination reveals a parotid gland tumor. An operative procedure is performed in which the tumor is removed from the parotid gland. Three months postoperatively the patient complains that her face sweats profusely when she tastes or smells food, and a diagnosis is made of Frey syndrome (gustatory sweating). Which of the following nerves was most likely injured during the procedure?

 A. Buccal
B. Inferior alveolar
C. Auriculotemporal
D. Facial
E. Lingual
A

C. Frey syndrome occurs following damage to
parasympathetic axons in the auriculotemporal nerve. When these postganglionic cholinergic axons grow peripherally after parotid surgery, they establish synapses upon the cholinergic sweat glands, which are innervated normally only by sympathetic firbers. As
the peripheral nerves make new connections, aberrant connections can be formed between the auriculotemporal nerve and other glands (not usually innervated by the auriculotemporal nerve). This results in flushing and sweating in response to the thought,
smell, or taste of food

42
Q

A 54-year-old male is to undergo bilateral thyroidectomy. During this procedure there is the possibility of bilateral paralysis of muscles that can open the airway. If a particular nerve is injured bilaterally,
there is significant risk of asphyxiation postoperatively
unless the patient is intubated or the airway is
opened surgically. Which of the following muscle
pairs opens the airway?

 A. Cricothyroids
B. Posterior cricoarytenoids
C. Arytenoideus
D. Thyroarytenoids
E. Lateral cricoarytenoids
A

B. The posterior cricoarytenoid muscle is the
only abductor of the larynx that opens the rima glottidis
and rotates the arytenoid cartilages laterally

43
Q

An 11-year-old boy with swollen palatine tonsils is
examined by an otolaryngologist. Which of the following
arteries supplies most of the blood to these tonsils and
must be protected when its tonsillar branch is divided?

 A. Ascending pharyngeal
B. Facial
C. Lingual
D. Descending palatine
E. Superior thyroid
A

B. The palatine tonsils are highly vascular and
are primarily supplied by the tonsillar branch of the
facial artery; therefore, care is taken to preserve this
artery while performing a tonsillectomy. The palatine
tonsil also receives arterial supply from the ascending
pharyngeal, the dorsal lingual, and the lesser palatine,
but the supply from the facial artery is by far the most
significant.

44
Q

A 55-year-old man with severe ear pain visits the
ENT doctor. During otoscopic examination the tympanic
membrane is ruptured. Which of the following
nerves is responsible for the sensory innervation of the
inner surface of the tympanic membrane?

 A. Glossopharyngeal
B. Auricular branch of facial
C. Auricular branch of vagus
D. Great auricular
E. Lingual
A

A. The inner surface of the tympanic membrane

is supplied by the glossopharyngeal nerve.

45
Q

A 45-year-old man was suffering from trigeminal
neuralgia (tic douloureux). The pain was so severe that the patient had considered suicide as a way to escape the
pain. Even light, gentle stimuli to the skin between the lower eyelid and the upper lip resulted in severe, agonizing pain. It was decided to lesion the nerve branch involved by injection of alcohol into the nerve. To reach the nerve, the needle will most likely need to be inserted
through which of the following openings?

 A. Foramen ovale
B. Foramen spinosum
C. Infraorbital foramen
 D. Mandibular foramen
E. Foramen magnum
A

C. The infraorbital branch of the maxillary division
of the trigeminal nerve exits the front of the
skull below the orbit through the infraorbital foramen.

46
Q

A 32 year old woman is undergoing a thyroidectomy.
Two months postoperatively the patient suffers
from loss of sensation within he larynx from the vocal
folds upward to the en ance into the larynx, allowing
for aspiration of liquids into the airway. Which of the
following nerves is most likely injured?

 A. Internal laryngeal nerve
B External laryngeal nerve
C. Glossopharyngeal nerve
D. Hypoglossal nerve
E. Recurrent laryngeal nerve
A

A. if there is an injury to the internal laryngeal
nerve there is a loss of sensation above the vocal
cords. In this case, for internal laryngeal injury to occur,
one must conclude that the operative field extended
above the position of the thyroid gland to the
level of the thyrohyoid membrane.

47
Q

A 55-year-old man is admitted to the emergency
department after slipping on wet pavement and falling.
Physical examination reveals that the patient has a hematoma hematoma
that formed in the danger zone of the scalp,
spreading to the area of the eyelids. Which of the following
layers is regarded as the “danger zone”?

 A. Loose, areolar layer
B. Skin
C. Galea aponeurotica
 D. Pericranium
E. Subcutaneous layer
A

A. The loose areolar connective tissue layer is
known as the “danger zone” because hematoma can
spread easily from this layer into the skull by means
of emissary veins that pass into and through the
bones of the skull

48
Q

A 45-year-old woman is admi ted to the hospital
with severe headache. The patient is diagnosed with
hypertension and arrhythmias To reduce the patient’s
blood pressure, massage is initiated at a p essure point
located deep to the anterior border of the sternocleidomastoid
muscle at the level of the superior border of
the thyroid cartilage. Which of the following structures
is targeted by the massage?

A. Carotid sinus
B Carotid body
C Thyroid gland
D. Parathyroid gland
E. Inferior cervical ganglion
A

A. The carotid sinus is a baroreceptor that can
be targeted for carotid massage to decrease blood
pressure. The carotid sinus receptors are sensitive to
changes in pressure. For this reason, sustained compression
of the carotid sinuses can lead to unconsciousness
or death as the heart rate is reflexively reduced.

49
Q

A 59-year-old painter fell from the scaffolding
and was admitted to the emergency department in an
unconscious condition. An emergency tracheostomy
is performed and brisk arterial bleeding suddenly occurs
from the midline incision over the trachea.
Which of the following vessels was most likely cut
accidentally?

A. Inferior thyroid branch of thyrocervical
trunk
B. Cricothyroid branch of the superior thyroid
artery
C. Thyroidea ima artery
D. Middle thyroid vein
E. Jugular arch connecting the anterior jugular
veins

A

C. The thyroidea ima artery supplies the thyroid
gland and ascends in the front of the trachea;
therefore, it would be easily injured in an emergency
tracheostomy with a midline incision over the trachea.

50
Q

A 21-year-old male baseball player is brought to
the emergency department after feeling severe dizziness.
During physical examination the patient demonstrates
lack of equilibrium and memory impairment. A
3-cm wound is noted in his scalp from an injury suffered
in a game several weeks earlier. A lumbar puncture
does not reveal blood in the cerebrospinal fluid.
Which of the following is the most likely diagnosis?

A. The middle meningeal artery was torn, resulting
in epidural hematoma.
B. There is a fracture in the pterion with injury
to the adjacent vasculature.
C. The injury resulted in the bursting of a preexisting
aneurysm of the anterior communicating
artery of the cerebral circle.
D. A cerebral vein is torn.
E. T he cavernous sinus has a thrombus.

A

D. A torn cerebral vein often results in a relatively
slow-bleeding subdural hematoma. Such a
hematoma can be involved in gradual compression of the brain, resulting in confusion, dizziness, clumsiness,
and memory loss. There would be no sign of
blood in the CSF because the bleeding is into the
subdural space, not the subarachnoid space. This
would fit the description of symptoms in this case.

51
Q

A 63-year-old man had his prostate gland tumor
removed 2 years before his present admission to the hospital, complaining of various neurologic problems, including headache. Radiographic examination reveals that the cancer has spread from the pelvis to the posterior cranial fossa by way of the internal vertebral venous plexus (of Batson). During physical examination the
patient’s right shoulder droops noticeably lower than the left, he exhibits considerable weakness in turning his head to the left, and his tongue points to the right when he attempts to protrude it directly from his mouth. There
are no other signifi cant fi ndings. Which of the following nerves are most likely affected?

A. Right vagus, right accessory, and right hypoglossal
nerves
B. Left accessory, right glossopharyngeal, right
vagus, and left hypoglossal nerves
C. Left hypoglossal, right trigeminal, and left
glossopharyngeal nerves
D. Right accessory and right hypoglossal nerves
E. Left facial, left accessory, right accessory, and vagus nerves

A

D. Paralysis of the right accessory and hypo
glossal nerves. Drooping of the right shoulder occurs as a result of paralysis of the trapezius as a result of injury to the right accessory nerve, which supplies that muscle. Loss of the right accessory nerve would also result in weakness in turning the head to the left, a function of the right sternocleidomastoid muscle which is supplied by this nerve. The tongue deviation
to the right is due to the unopposed activity of the left tongue muscles since the right hypoglossal nerve
(which innervates the right tongue muscles) is affected.

52
Q

A 3-month-old male infant is admitted to the
hospital because he cries continuously During physical
examination it is observed that he infant ha a dry
right eye. Upon the basis of imaging studies, the neuroophthalmologist
diagnoses a lesion at the neural
cell bodies of the preganglionic axons of the pterygopalatine
ganglion. Which of the following structures
contains the neural cell bodies of the preganglionic
axons?

 A. Superior cervical ganglion
B. Edinger-Westphal nucleus
C. Superior salivatory nucleus
D. Inferior salivatory nucleus
E. Nucleus ambiguus
A

C. The neural cell bodies whose axons synapse
in the pterygopalatine ganglion are located in the superior
salivatory nucleus, which is in the pons; this
nucleus provides the GVE firbers of the facial nerve for
lacrimal and salivary secretion.

53
Q

A 14 yr old female has been suffering from
quinsy in the right side of her oropharynx. In surgical removal of the pathologic tissue, or for incision and drainage of the area, which of the following arteries
will be at greatest risk?

 A. Lingual
B. A branch of facial
C. Superior laryngeal artery
D. Ascending pharyngeal artery
 E. Descending palatine artery
A

B. A branch of the facial artery would be of
primary concern because its branches supply the
oropharynx and it is the primary source of arterial
supply to the palatine tonsil

54
Q

A 17-year-old female visits the family dermatologist because of severe facial acne. During physical examination it was found that there was a rather obvious
and painful lesion on the side of her nose. The patient was given antibiotics and warned not to press or pick at the large, inflamed swelling. If she were to squeeze, prick, or incise such a lesion in the area between the
eye and the upper lip, or between the eye and the side of the nose, the infection could spread to the cavernous sinus. Which of the following pathways of spread of infection would be most typical?

A. Nasal venous tributary to angular vein, to
superior ophthalmic vein, then to cavernous
sinus
B. Retromandibular vein to supraorbital vein,
then to inferior ophthalmic vein, then to cavernous
sinus
C Dorsal nasal vein to superior petrosal vein,
then inferior ophthalmic vein to cavernous
sinus
D. Facial vein to maxillary vein, then middle
meningeal vein to cavernous sinus
E. Transverse facial vein to superfi cial temporal
vein to emissary vein to cavernous sinus

A

A. Infection in the danger area of the face can
lead to cavernous sinus thrombosis because infection
spreads from the nasal venous tributary to the angular
vein, then on to the superior ophthalmic vein,
which passes into the cavernous sinus.

55
Q

A 73-year-old male patient visits the outpatient
clinic with a complaint of progressive, painless loss of vision. Radiographic examination reveals thrombophlebitis
of the cavernous sinus. Through which of the following
structures must a thrombus pass to cause the
symptoms of this patient?

 A. Subarachnoid space
B. Central artery of the retina
C. Central vein of the retina
D. Optic chiasm
E. Ciliary ganglion
A

C. The thrombus may pass through the central
vein of the retina to reach the cavernous sinus. The
patient would suffer blindness because the central
vein is the only vein draining the retina and if it is
occluded, blindness will ensue.

56
Q

A 67-year-old man visits the outpatient clinic
with complaints of deteriorating vision. A form of glaucoma
is diagnosed in which the aqueous humor does
not drain properly into the scleral venous sinus at the iridoscleral angle of the eyeball. The aqueous fluid is secreted by the epithelium of the ciliary body directly
into which of the following spaces?

 A. Iridoscleral angle
B. Posterior chamber
 C. Pupil
D. Vitreous body
E. Lacrimal sac
A

B. Aqueous humor is secreted by the ciliary
body into the posterior chamber of the eye. The humor
fl ows through the pupil into the anterior chamber
and then is fi ltered by a trabecular meshwork,
then drained by the canal of Schlemm

57
Q

A 2-month-old female infant is hospitalized with
hydrocephalus. Radiographic examination reveals cerebrospinal
fl uid between the compressed brain and
overlying bones of the skull. Which of the following
conditions will most likely lead to this type of clinical
picture?

A. Lack of filtration through arachnoid granulations
B. Occlusion of cerebral aqueduct (of Sylvius)
C. Blockage of the foramina of Luschka
D. Congenital absence of the foramen of Magendie
E. Closure of the interventricular foramina of
Monro

A

A. If there is CSF between the compressed
brain and overlying skull bones, the problem must be a condition of communicating hydrocephalus, with inadequate drainage through the arachnoid granulations into the superior sagittal sinus.

58
Q

A 54-year-old man was admitted to the emergency
department after he was struck by an automobile.
Radiographic examination revealed a fracture
through the crista galli of the anterior cranial fossa,
resulting in slow, local bleeding. Which of the following
is the most likely source of bleeding?

A. Middle meningeal artery
B. The great cerebral vein of Galen
C. Superior sagittal sinus
D. Straight venous dural sinus
E. Superior ophthalmic vein
A

C. The superior sagittal sinus would most likely
be the source of the bleeding because it attaches anteriorly
to the crista galli and because of the slow
nature of the bleed.

59
Q

During the routine ophthalmologic exam, the
globe, the retina, and the cornea of each eye are tested
Which of the following nerves must be functioning
properly if the patient is to be able to turn the eye laterally
(abduction) without diffi culty and without pward
or downward deviation?

A. Superior division of oculomotor, ophthalmic
nerve, abducens nerve
B. Trochlear nerve, abducens nerve, nasociliary
nerve
C. Inferior division of oculomotor, trochlear,
abducens
D. Oculomotor and ophthalmic nerves
E. Superior division of oculomotor, trochlear,
and abducens nerves

A

C. For proper movements of the eye to occur,
all cranial nerves of the extraocular eye muscles are
required (oculomotor, trochlear, and abducens
nerves) The inferior division of the oculomotor innervates the inferior rectus, the medial rectus, and
the inferior oblique. Lateral movement of the eye is
initiated by the lateral rectus (abducens nerve), assisted thereafter by the superior oblique (trochlear nerve). The inferior rectus (inferior division of the
oculomotor nerve) balances the upward deviation
exerted by the superior rectus (superior division of
the oculomotor nerve). The medial rectus (superior
division of the oculomotor nerve) must relax to facilitate
the lateral excursion.

60
Q

a 34 year old woman is admitted to the hospital
because of hoarseness for the past 3 months. Radiographic
examination reveals a cancerous growth in her
larynx with no evidence of metastasis. In addition, the area in which the tumor is growing is characterized by very limited lymphatic drainage. Which of the following locations is most likely to contain a tumor with
these characteristics?

 A. Anterior commissure of the vocal ligaments
B. Interarytenoid fold
C. Laryngeal ventricle
D. Cricothyroid ligament
E. Middle segment of the vocal cord
A

E. The middle of the vocal cord would be the
most likely location of the tumor because there is no
direct lymph drainage from this region.

61
Q

A 55-year-old man is admitted to the hospital
with a complaint of severe headaches. A lumbar puncture
reveals traces of blood in the cerebrospinal fl uid.
Which of the following conditions has most likely occurred
in this patient?

A. Fracture of the pterion with vascular injury
B. A ruptured “berry” aneurysm
C. Leakage of branches of the middle meningeal
vein within the temporal bone
D. A tear of the cerebral vein at the entrance to
the superior sagittal sinus
E. Occlusion of the internal carotid artery by a
clot gener ted in the left atrium

A

B. When a berry aneurysm ruptures, the blood
flows into the subarachnoid space and therefore
mixes with CSF; thus, blood would be present in the
CSF when a lumbar puncture is performed.

62
Q

A 55 yr old man is admitted to the neurosurgical
clinic for a scheduled removal of a tumor in the
left jugular canal. Posto eratively, the patient has no
gag refl ex when the ipsilateral pharyngeal wall is
stimulated, although the pharynx moved upward, and
a gag refl ex resulted when the right pharyngeal wall
was stimulated. The uvula was deviated to the right
and the left vocal cord had drifted toward the midline.
Wh ch of the following structures will contain the
neural cell bodies for the motor supply of the paralyzed
muscles?

 A. Nucleus solitarius
B. Trigeminal motor nucleus
C. Dorsal motor nucleus
D. Nucleus ambiguus
E. Superior or inferior ganglia of vagus
A

D. The nucleus ambiguus gives rise to efferent
motor fibers of the vagus nerve, which supply the
laryngeal and pharyngeal muscles. If supply to this
region is interrupted, an individual loses the swallowing,
cough, and gag reflexes.

63
Q

A 65-year-old man is admitted to the emergency
department after his head hit the dashboard in an automobile
collision. Radiographic and physical examinations
reveal that the inferior alveolar nerve is injured at
its origin. Which of the following muscles would most
likely be paralyzed as a result?

 A. Geniohyoid
B. Hyoglossus
C. Mylohyoid
D. Stylohyoid
E. Palatoglossus
A

C. Just before it passes into the mandible to
supply the lower teeth and chin, the inferior alveolar
nerve gives rise to the mylohyoid nerve, a motor
nerve supplying the mylohyoid and anterior belly of
the digastric

64
Q

A 64-year-old man is admitted to the hospital in
an unconscious condition. A CT scan examination reveals
that the patient has suffered a cerebral vascular
accident (stroke), with a small hematoma produced by the superior cerebellar artery. Which of the following
nerves will most likely be affected by the hematoma?

 A. Trochlear nerve
B. Abducens nerve
C. Facial nerve
D. Vestibulocochlear nerve
E. Glossopharyngeal nerve
A

The trochlear nerve passes between the posterior
cerebral artery and the superior cerebellar artery,
and therefore a hematoma of the superior cerebellar
artery can easily injure the trochlear nerve,
which runs alongside the internal carotid artery and
then enters the orbit through the superior orbital fissure.

65
Q

A 65-year-old male is admitted to the hospital
three weeks after a “small bump of his head” according
to his narrative. He suffered the accidental bump from
a low-hanging branch while driving his tractor through
the apple orchard during harvesting season. During
physical examination the patient displays mental confusion
and poor physical coordination. Radiographic
examination reveals leakage from a cerebral vein over
the right cerebral hemisphere. From what type of
bleeding is the patient most likely suffering?

 A. Subarachnoid bleeding
B. Epidural bleeding
C. Intracerebral bleeding into the brain parenchyma
D. Subdural bleeding
E. Bleeding into the cerebral ventricula
A

D. Subdural bleeding usually results from tears
in veins that cross the subdural space, between the
dura and the arachnoid. This bleeding may cause a
gradual increase in intracranial pressure and may result
in leakage of venous blood over the right cerebral
hemisphere with a variable rate of progression.

66
Q

A 27-year-old man is admitted to the hospital after
a middleweight boxing match. During physical examination
the strength and symmetry of strength in
opening the jaws are tested. Which of the following
muscles is the most important in jaw protrusion and
depressing the mandible?

 A. Anterior portion of temporalis
B. Lateral pterygoid
C. Medial pterygoid
D. Masseter
E. Platysma
A

B. The lateral pterygoid muscle is a muscle of
mastication innervated by the lateral pterygoid nerve
of the mandibular division of the trigeminal nerve.
The lateral pterygoid acts to protrude the mandible
and open the jaw.

67
Q

A 31 yr old mother visits the pediatric outpatient
clinic with her 6-month-old baby complaining
that her baby is not developing quickly and has no
teeth. Which of the following teeth are expected to appear
first?

A. Superior medial incisors at 8 to 10 months of
age
B. Inferior medial incisors at 6 to 8 months of
age
C. Superior lateral incisors at 8 to 10 months of
age
D. Inferior lateral incisors at 12 to 14 months of
age
E. First molar at 6 to 8 months of age

A

B. The order of tooth eruption is a follows: inferior
medial incisors (6 to 8 months), superior medial
incisors (8 to 10 months), first molar (6 to 8 months),
superior lateral incisors (8 to 10 months), and finally
inferior lateral incisors (12 to 14 months).

68
Q

A 56-year-old man visits the outpatient clinic with
a complaint of severe headaches and ear pain. Radiographic
examination reveals a tumor in the middle ear
cavity, invading through the bony floor. Which of the
following structures will most likely be affected?

A. The cochlea and lateral semicircular canal
B. The internal carotid artery
C. The sigmoid venous sinus
D. The internal jugular bulb
E. The aditus ad antrum of the mastoid region
and the facial nerve

A

D. The sigmoid sinus collects venous blood
from the transverse sinuses and empties it into a
small cavity known as the jugular bulb, the inferior
portion of which is located beneath the bony floor of
the middle ear cavity.

69
Q

A 52-year-old man is admitted to the emergency
department with a bullet wound in the infratemporal
fossa. During physical examination it is observed that
the patient has lost unilateral sensa ion of hot, cold,
pain, and pressu e from the front part of the tongue,
but taste and salivary function are preserved. Which of
the following is the most likely diagnosis?

A. The facial nerve was transected distal to the
origin of the chorda tympani.
B Receptors for hot, cold, pain, and pressure are
absent in the patient’s tongue.
C. The glossopharyngeal nerve has been injured
in the pharynx.
D The superior laryngeal nerve was obviously
severed by the bullet.
E. The lingual nerve was injured at its origin
near the foramen ovale.

A

E. The lingual nerve supplies sensory innervation
to the mucous membrane of the anterior two
thirds of the tongue, taste sensation to the anterior
part of the tongue, and parasympathetic fibers to the oral salivary glands.