prep u head and neck

Choose the appropriate lettered structure in this radiograph of the lateral view of the head (see figure). Cerebrospinal fluid is formed by vascular choroid plexus in which structure?

Cerebrospinal fluid is formed by vascular choroid plexus in the ventricles in the brain; the letter "A" indicates the lateral ventricle.

In the ED, you examine a patient complaining of severe maxillary sinus pain. Upon looking in his mouth, you observe severely degenerated maxillary molars. The patient admits that he has not been treated by a dentist for many years and recently had an upper posterior toothache. Which of the following is the most likely cause of the patient's pain? An infection from an upper molar has spread along the inferior alveolar nerve to the maxillary sinus An infection has spread via the root of an upper maxillary molar into the maxillary sinus Poor dental hygiene has resulted in maxillary alveolar bone retraction causing the pain An infection has spread from an upper molar along the inferior alveolar artery to the maxillary sinus Poor dental hygiene has weakened the maxillary facial buttress causing both the toothache and sinus pain

Explanation: The answer is an infection has spread via the root of an upper maxillary molar into the maxillary sinus. Because the roots of the maxillary molar teeth extend into the maxillary sinus, infection of one of these teeth may cause sinusitis and pain in the sinus.

Upon neurological examination, you notice a slow pupillary light reflex in a patient's right eye. Which of the following is consistent with this sign? Lesion of the right nasociliary nerve Compression of the right oculomotor nerve Compression of the right facial nerve proximal to the geniculate ganglion Compression of the right facial nerve distal to the geniculate ganglion Lesion of the left long ciliary nerves

Explanation: The answer is compression of the right oculomotor nerve. The pupillary light reflex involves the optic nerve as the afferent limb and the oculomotor nerve as the efferent limb. The first sign of compression of the oculomotor nerve is ipsilateral slowness of the pupillary response to light.

A 22-year-old patient has dryness of the corneal surface of his eye because of a lack of tears. Which of the following nerves may be damaged? Zygomatic branch of the facial nerve Deep petrosal nerve Greater petrosal nerve Proximal portion of the lacrimal nerve Lesser petrosal nerve

Explanation: The answer is greater petrosal nerve. The secretomotor fibers to the lacrimal gland are parasympathetic fibers that run in the facial, greater petrosal, vidian (nerve of the pterygoid canal), maxillary, zygomatic (of maxillary), zygomaticotemporal, and lacrimal (terminal portion) nerves. The lesser petrosal nerve carries secretomotor (preganglionic parasympathetic) fibers to the parotid gland. The deep petrosal nerve contains postganglionic sympathetic fibers. The zygomatic branch of the facial nerve supplies the facial muscles.

While jogging on a trail you come upon a child who fell off her bike and has severe facial lacerations that are bleeding profusely. In order to most effectively curtail the bleeding, where would you put pressure (bilaterally)? Horizontal ramus of the mandible just anterior to the attachment of the masseter Condylar process of mandible Coronoid process of mandible Infraorbital foramen Lateral aspect of mastoid process

Explanation: The answer is horizontal ramus of the mandible just anterior to the attachment of the masseter. The facial artery is easily palpable and compressible as it winds around the inferior border of the mandible immediately anterior to the masseter muscle.

The buccopharyngeal fascia is continuous with _____________. the carotid sheath. prevertebral fascia. deep investing fascia. superficial fascia. pretracheal fascia.

Explanation: The answer is pretracheal fascia. As the pharynx is essentially continuous with the trachea, the fascia of the pharynx (buccopharyngeal) is continuous with the fascia of the trachea (pretracheal).

Adenoids are inflamed what? Lymph nodes Pharyngeal tonsils Lingual tonsils Palatine tonsils Tubal tonsils

Inflamed pharyngeal tonsils are often referred to as adenoids.

A performer at the traveling circus for the state fair has injured her shoulder during a routine. When she fell off the trapeze, she struck the ground on her back, and most of the blunt force was directed toward her shoulders. A crush injury of the suboccipital nerve would result in paralysis of which of the following muscles? Trapezius Rectus capitis posterior major of the back Splenius capitis Levator scapulae Iliocostalis

Rectus capitis posterior major of the back

A 33-year-old woman presents with rapid weight gain, particularly in the trunk and face with sparing of the limbs, excess sweating, thinning of the skin, and hirsutism (facial male-pattern hair growth). A full examination also reveals bitemporal hemianopsia (or tunnel vision). What of the following labeled areas on the given X-ray of the lateral skull will be of most interest to the physician?

The answer is C (hypophyseal fossa). This patient is exhibiting symptoms associated with Cushing disease, which results from the presence of a noncancerous tumor (adenoma) in the pituitary gland. The pituitary gland (or hypophysis) lies in the hypophyseal fossa of the sphenoid bone, which is identified by the "C" in this standard lateral plane film (X-ray) of the head. This fossa is part of the sella turcica, a complexly shaped part of the sphenoid located in the center of the floor of the cranial cavity. Cushing disease, also called pituitary adrenocorticotropic hormone (ACTH) hypersecretion, causes elevated cortisol levels, which lead to rapid weight gain, particularly in the face and trunk with sparing of the limbs (central obesity), excess sweating, thinning of the skin, muscle weakness, and hirsutism (facial hair growth). These symptoms are all part of Cushing syndrome, but Cushing disease refers specifically to the presence of a pituitary adenoma. The presence of a pituitary adenoma can be confirmed with an MRI of the pituitary gland. In this patient, the expanding pituitary adenoma expands upward out of the hypophyseal fossa to impinge about the optic chiasm, causing the bitemporal hemianopsia (tunnel vision). This visual deficit further implicates the pituitary gland as the location of the mass. The pituitary fossa (and its bounding parts of the sella turcica) is clearly defined and serves as a major orientation point in a lateral X-ray of the head.

A 35-year-old man complains to his physician that he feels congested, has trouble with nasal breathing, and is experiencing a yellowish nasal mucus discharge. He also mentions that his right side upper molar teeth ache terribly. A thorough physical examination reveals maxillary sinusitis. The discharge from this sinus initially drains into the nasal cavity at which of the labeled points within this drawing of the lateral nasal wall?

The answer is C (middle nasal meatus). The lateral nasal wall is formed largely by three nasal conchae (turbinate bones). The superior and middle conchae are parts of the ethmoid bone. The inferior concha is an independent bone. The conchae divide the nasal passage into four air channels: the sphenoethmoidal recess (above the superior concha), the superior meatus (below the superior concha), the middle meatus (below the middle concha), and the inferior meatus (below the inferior concha). The paranasal sinuses open into the nasal passage on its lateral wall, in specific relations to the conchae and meati. The maxillary sinus is the largest paranasal sinus, occupying much of the maxillary bone. Infections there may affect the upper teeth, causing a toothache, because the sinus cavity is separated from the roots of the teeth by only a very thin layer of bone. The maxillary sinus opens into the most posterior part of the semilunar hiatus in the middle meatus. The frontal, anterior ethmoidal, and middle ethmoidal sinuses also open nearby into the middle meatus. A (sphenoethmoidal recess) is incorrect. The sphenoethmoidal recess receives the drainage of the sphenoidal sinus. B (superior nasal meatus) is incorrect. The superior nasal meatus contains the opening of the posterior ethmoidal sinuses (air cells). D (inferior nasal meatus) is incorrect. The inferior nasal meatus does not receive the opening of any paranasal sinus. Instead, it contains the opening of the nasolacrimal duct, thus receiving drainage of tears from the eye. E (pharyngotympanic tube) is incorrect. The pharyngotympanic (auditory; eustachian) tube opens into the nasopharynx, posterior to the nasal passage. It is not a component of any nasal meatus.

Choose the appropriate lettered structure in this MRI scan showing a transaxial section through the head (see figure). Which structure may be obliterated by a pituitary tumor?

The answer is C. The suprasellar cistern can be obliterated by a pituitary tumor.

An 8-year-old boy suffers a fracture at the base of the skull from the impact of a terrorist bomb explosion. The skull trauma includes a lesion of the vagus nerve. Damage at which of the indicated openings would injure the vagus nerve?

The answer is E (jugular foramen). The jugular foramen is a large opening that connects the posterior cranial fossa with the exterior base of the skull. It is divided into an anterior and a posterior compartment for its major contents. The anterior compartment transmits a bundle of three cranial nerves out of the cranial cavity: the glossopharyngeal nerve (CN IX), the vagus nerve (CN X), and the (spinal) accessory nerve (CN XI). The superior ganglia of the glossopharyngeal and vagus nerves are located within the jugular foramen, whereas the inferior ganglia are situated just outside it. Upon exiting the jugular foramen, the nerves immediately diverge from one another to pass to their target regions. The posterior compartment transmits the internal jugular vein. This large vessel originates at the terminal end of the sigmoid dural sinus, at the internal opening of the jugular foramen. Thus, trauma to the jugular foramen can have significant and widespread vascular and neural consequences.

A 33-year-old woman develops Bell's palsy. She must be cautious because this can result in corneal inflammation and subsequent ulceration. This symptom results from which of the following conditions? Absence of the corneal blink reflex Sensory loss of the cornea and conjunctiva Lack of secretion of the parotid gland Absence of sweating on the face Inability to constrict the pupil

The answer is absence of the corneal blink reflex. Bell's palsy (facial paralysis) can involve inflammation of the cornea, leading to corneal ulceration, which probably is attributable to an absence of the corneal blink reflex. This is due to paralysis of the orbicularis oculi, which closes the eyelid. Sensory loss of the cornea and conjunctiva is due to injury of the ophthalmic nerve. Lack of secretion of the parotid salivary gland is due to injury of the glossopharyngeal, tympanic, or lesser petrosal nerve. Absence of sweating is due to damage of the sympathetic nerve. Inability to constrict the pupil is due to paralysis of the sphincter pupillae or damage of parasympathetic nerve fibers to the sphincter.

The buccinator is innervated by _______________. the mandibular division of the trigeminal nerve. parasympathetics from the pterygopalatine ganglion. cranial nerve VII. cell bodies located in the trigeminal ganglion. sympathetics from the cervical region.

The answer is cranial nerve VII. The buccinator is a muscle of facial expression, and like all muscles of facial expression, it is innervated by CN VII.

A 29-year-old baseball player whose head is hit by a high-speed baseball is brought to an emergency department. Physical examination and radiogram reveal fracture of the temporal bone and damage to the lesser petrosal nerve. Which of the following conditions could occur as a result of injury to the lesser petrosal nerve? Constriction of the pupil Ptosis of the upper eyelid Lack of submandibular gland secretion Lack of lacrimal secretion Lack of parotid gland secretion

The answer is lack of parotid gland secretion. Parasympathetic preganglionic fibers in the lesser petrosal nerve enter the otic ganglion where they synapse, and postganglionic parasympathetic fibers join the auriculotemporal nerve to supply the parotid gland for secretion of saliva. The other conditions are not caused by a lesion of the lesser petrosal nerve.

A 36-year-old man flips over the handlebars of his motorcycle and falls on the asphalt pavement, striking his head. He was not wearing a helmet. Although alert after the fall, he has a clear nasal discharge that tests positive for glucose. The patient most likely has a fracture of which of the following bones? Ethmoid Vomer Sphenoid Maxilla Frontal

The answer is ethmoid. A fracture of the ethmoid bone, specifically its cribiform plate, which separates the nasal cavity from the anterior cranial fossa, would enable cerebrospinal fluid (CSF), the clear discharge that tests positive for glucose, to leak from the nose. The traumatic blow to the head has broken the cribiform plate of the ethmoid bone, which caused a communication between the patient's anterior cranial fossa and nasal cavity, which is noted by the black arrow in the given sagittal CT scan. This patient presents with CSF rhinorrhea, when can lead to meningitis and other intracranial complications, and this condition can be lethal if not properly treated. The given sagittal CT shows several fracture sites, including within the cribiform plate of the ethmoid bone as well as fractures of the anterior and posterior walls of the frontal sinus. The cribiform plate is fractured in several locations, and one of these fracture sites is indicated by the white arrow in the given CT.

A tumor is discovered embedded in the posterior wall of the tympanic cavity in a 45-year-old man. If the tumor erodes through this wall, which of the following structures will it first encounter? Internal jugular vein Tympanic membrane Brain Internal carotid artery Facial nerve

The answer is facial nerve. The tympanic (middle ear) cavity is a small air-filled space within the petrous part of the temporal bone. Its position, shape, and relations make for challenging spatial concepts in anatomy because it is buried so deeply within the skull. It has six walls: the roof (tegmental wall), floor (jugular wall), anterior (carotid) wall, posterior (mastoid) wall, medial (labyrinthine) wall, and lateral (membranous) wall. Each wall has a close relationship to one or more significant neighboring structures. The upper part of the posterior wall contains an opening (aditus) that leads to the mastoid antrum and air cells. The distal limb of the facial canal (containing the main branch of the facial nerve) descends below the aditus, behind the posterior wall, on its way to its termination at the stylomastoid foramen. Thus, a tumor piercing the posterior wall may invade the facial canal and/or the mastoid air sinuses. Internal jugular vein is incorrect. The superior bulb of the internal jugular vein lies beneath the floor (jugular wall) of the tympanic cavity. Because this tumor is embedded in the posterior wall of the middle ear cavity, the internal jugular vein would not be affected.

A 13-year-old girl visits her pediatrician complaining of loss of sensitivity in her lower eyelid, the skin below her right eye, and in her upper lip and teeth. Which of the following sites is the most likely location for the nerve lesion responsible for these signs and symptoms? Foramen ovale Foramen spinosum Optic canal Foramen rotundum Superior orbital fissure

The answer is foramen rotundum. The foramen rotundum is an opening in the greater wing of the sphenoid bone that enables the maxillary (second) division of the trigeminal nerve (CN V2) to pass into the middle cranial fossa. CN V2 supplies sensory (cutaneous) innervation to the skin to the lower eyelid, cheek, upper lip, upper dentition and gingivae, and lateral aspects of the nose. Due to the sensory deficits within this patient, this nerve is damaged along its route, and the foramen rotundum is the most likely location.

The above axial CT image is of a child with a 4th ventricle mass (arrow) that is blocking his cerebral aqueduct. You would expect CT images cephalad to the one shown to reveal which of the following? Subdural hematoma Arachnoid granulosis Cerebral contusion Stroke Hydrocephalus

The answer is hydrocephalus. Hydrocephalus results from either an overproduction of CSF, or blockage of its flow, as in this case.

A 22-year-old man receives a stab wound in the left anterior cervical region, at the C2 vertebral level. The wound was 3 cm deep and located anterior to the sternocleidomastoid muscle (SCM) and superior to the greater horn of the hyoid bone. During a postoperative examination, the patient displays dysarthria, or difficulty speaking. Which of the following structures is most likely damaged? Accessory nerve Hypoglossal nerve Roots of the brachial plexus Mandibular division of trigeminal nerve Lingual branch of glossopharyngeal nerve

The answer is hypoglossal nerve. The left hypoglossal nerve (CN XII) is located in the anterior cervical region at the location of the stab wound. CN XII innervates all of the intrinsic muscles of the tongue and most of its extrinsic muscles with the lone exception being the palatoglossus muscle, innervated by the vagus nerve (CN X). Therefore, damage to the right CN XII would produce dysarthria, or difficult speaking, which was seen in this patient due to the loss of innervation to the tongue musculature. Though not noted in this patient, damage to the hypoglossal nerve also causes ipsilateral deviation of the tongue due to the unopposed muscular contractions of the contralateral genioglossus muscle. The mnemonic "The tongue licks the wound" will help you remember that the tongue deviates to the ipsilateral side in a lower motor neuron lesion of CN XII.

A 47-year-old man cannot move his eye laterally. Which of the following conditions would cause this type of inability to move the eye? Infection in the cavernous sinus Tumor of the pituitary gland Occlusion of the posterior cerebral artery Infection in the maxillary sinus Tumor in the anterior cranial fossa

The answer is infection in the cavernous sinus. The abducent nerve, which innervates the lateral rectus muscle, runs through the middle of the cavernous sinus. The other conditions listed do not injure the abducent nerve. A tumor in the pituitary gland may injure the optic chiasma, causing bitemporal hemianopsia.

A 76-year-old man with swallowing difficulties undergoes imaging for a possible mass. The CT scan image at the level of the cricothyroid ligament in his neck should show which of the following structures? Thyrocervical trunks Internal laryngeal nerves Inferior laryngeal nerves External carotid arteries Inferior thyroid veins

The answer is inferior laryngeal nerves. A computed tomography (CT) scan through the cricothyroid ligament shows the inferior laryngeal nerves, which are the terminal portion of the recurrent laryngeal nerves above the lower border of the cricoid cartilage. The external carotid arteries and the internal laryngeal nerves lie above the cricothyroid ligament, and the inferior thyroid veins and the thyrocervical trunks lie below the ligament.

A dentist is about to inject a needle with an anesthetic solution into a foramen in the palate directly posterior to the space between the central incisors. What is the nerve the dentist is trying to anesthetize? Nasopalatine Greater palatine Lesser palatine Posterior superior alveolar Glossopharyngeal

The answer is nasopalatine. A nasopalatine nerve block is performed by injecting the needle into the incisive foramen.

A 64-year-old woman is unable to open her mouth or jaw because of tetanus resulting from a penetrating wound from a rusty nail. Which of the following muscles would most likely be paralyzed? Medial pterygoid muscle Temporalis muscle Masseter muscle Buccinator muscle Lateral pterygoid muscle

The answer is lateral pterygoid muscle. The lateral pterygoid muscle opens the mouth by depressing the jaw. The masseter, medial pterygoid, and temporalis muscles close the jaw. The buccinator muscle is a muscle of facial expression.

A physician directs a small light into only the left eye of a patient to test pupillary constriction. The left pupil does not respond to the light; however, the right pupil constricts. What nerve is most likely damaged in this patient? Left oculomotor nerve Right oculomotor nerve Left optic nerve Right ophthalmic nerve Right optic nerve

The answer is left oculomotor nerve. The left oculomotor nerve (CN III) is damaged in this patient. The physician is performing the pupillary light reflex, which tests the integrity of the sensory and motor functions of the eye. The afferent limb of the reflex is the optic nerve, and the efferent limb is the oculomotor nerve. In this patient, the constriction of the right pupil (a consensual response to the light) implies the afferent limb (left optic nerve) of the light reflex is intact because one of the pupils responded to the light. However, the efferent limb of the left eye is likely damaged due to the lack of a direct response (pupillary constriction) to the light. Under normal circumstances, both pupils constrict in response to increased light intensity due to a bilateral projection from the pretectal nucleus within the upper medulla to the Edinger-Westphal nucleus, which then projects its parasympathetic fibers along the oculomotor nerve causing pupillary constriction

A 60-year-old man is unable to open his eye because of a rare neuromuscular disease. Which of the following muscles would most likely be paralyzed?

The answer is levator palpebrae superioris. The levator palpebrae superioris muscle opens the eye by elevating the upper eyelid. The orbicularis oculi closes the eye, the orbicularis oris closes the lips, the frontalis elevates the eyebrow, and the superior rectus elevates the eyeball.

A 23-year-old man has an impacted left third mandibular molar (or wisdom) tooth extracted. Following the surgery, the patient reports numbness in the anterior aspect of his tongue. Which of the following nerves is damaged? Mylohyoid nerve Lingual nerve Inferior alveolar nerve Glossopharyngeal nerve Chorda tympani nerve

The answer is lingual nerve. The lingual nerve is a branch of the mandibular division of the trigeminal nerve (CN V3), which traverses the foramen ovale and resides in the infratemporal fossa. This nerve supplies general sensation to the anterior two thirds of the tongue, and this nerve is at risk during extraction of an impacted third mandibular molar tooth.

An elderly patient presents with a thyroid mass. Needle biopsy showed this to be an anaplastic thyroid carcinoma. These are aggressive malignancies that often penetrate the thyroid capsule and invade structures adjacent to the thyroid gland. You suspect tumor invasion of both of the recurrent laryngeal nerves because of all the following except: Inability to fully abduct the vocal folds Stridor Almost complete inability to speak Inability to abduct the vestibular folds Loss of all sensation from the larynx

The answer is loss of all sensation from the larynx. The internal branch of the superior laryngeal nerve supplies sensation to the superior aspect of the larynx.

Following right parotid gland surgery to remove a tumor, a 45-year-old woman found that saliva was constantly dripping from the right margin of her mouth. The surgery apparently damaged which nerve? Right temporal branch of facial nerve Mental nerve Infraorbital nerve Marginal mandibular branch of facial nerve Buccal branch of trigeminal nerve

The answer is marginal mandibular branch of facial nerve. The marginal mandibular branch of the facial nerve supplies the muscles of the lower lip. The facial nerve traverses the parotid gland and branches of it are susceptible to injury during parotid gland surgery.

A 23-year-old female professional student wakes up with a facial nerve (CN VII or Bell) palsy. What muscle will continue to function despite this affliction? Levator labii superioris Masseter Zygomaticus major Platysma Buccinator

The answer is masseter. Damage to the facial nerve would lead to loss of innervation to the muscles of facial expression, and the masseter muscle, a muscle of mastication, is the only listed muscle that will continue to function in a patient diagnosed with facial nerve (CN VII or Bell) palsy. The mandibular (third) division of the trigeminal nerve (CN V3) supplies the four muscles of mastication (masseter, temporalis, lateral pterygoid, and medial pterygoid) and four additional muscles: Mylohoid, Anterior belly of the Digastric, Tensor Tympani, and Tensor Veli Palatini (mnemonic = "MATT"). The masseter muscle primarily works to close the jaw, though its superficial fibers may play a limited role in protrusion of the mandible. It is the only muscle on this list of options that would continue to function in facial nerve palsy. Zygomaticus major is incorrect. The zygomaticus major is a muscle of facial expression, so it would be paralyzed in facial nerve palsy. It functions as a dilator of the oral fissure by elevating the corners of mouth, as in smiling when the muscle contracts bilaterally or sneering to show disdain when the muscle contracts unilaterally. It originates on the lateral aspect of the zygomatic bone, which is how it receives its name. Levator labii superioris is incorrect. The levator labii superioris is a muscle of facial expression, so it would be paralyzed in facial nerve palsy. It functions as a dilator of the oral fissure by retracting (elevating) the upper lip to show the upper teeth and deepens the nasolabial sulcus. It originates on the infraorbital margin of maxilla, above, and therefore covers, the infraorbital foramen. Buccinator is incorrect. The buccinator is a muscle of facial expression, so it would be paralyzed in facial nerve palsy. It originates on the alveolar ridges of maxillary and mandibular molar teeth and contracts to give tension to the cheek to keep food between the occlusal surfaces of the teeth. The tone of the buccinator muscle provides resistance to keep teeth from tilting laterally and prevents patients from looking like a hamster, with food lodged in the oral vestibule, when they chew food. Platysma is incorrect. The platysma is a muscle of facial expression, so it would be paralyzed in facial nerve palsy. It resides in the neck and lower face to depress the mandible and wrinkle the skin of neck, as seen when a person is placed in a stressful situation. The platysma originates in the subcutaneous tissue near the clavicle and inserts into the modiolus, lateral to the labial commissures.

A 55-year-old man presented with painful vesicles on his chin and lower lip. He was diagnosed with a dermatomal herpes zoster inflammation (shingles). Which of the following nerves likely transmitted the sensations of pain? Mental Marginal mandibular branch of facial Infraorbital Auriculotemporal Buccal

The answer is mental. The mental nerve (branch of mandibular nerve) supplies the chin with sensory innervation.

Your 1-year-old has an infection that has reached his mastoid process (mastoiditis). A classical surgical approach has been to drain the primary infection via the mastoid antrum. What is the cavity the surgeon plans to drain via this route? Inner ear Middle ear External ear Nasopharynx Ethmoidal sinus

The answer is middle ear. Mastoditis can result from a middle ear (tympanic cavity) infection. In children, this chamber is easily reached surgically because the bone within the antrum leading to the middle ear cavity is very thin.

While participating in a bar fight, the orbit of a 25-year-old man is pierced by a broken pool cue stick, which extends back to the superior orbital fissure. Which of the following nerves is most likely damaged? Maxillary division of trigeminal Ophthalmic division of trigeminal Mandibular division of trigeminal Optic nerve Facial nerve

The answer is ophthalmic division of trigeminal. The ophthalmic (first) division of trigeminal nerve (CN V1) supplies sensory (cutaneous) innervation to the skin of the upper eyelid, anterior aspect of the nose, forehead, and anterior scalp. CN V1 enters the middle cranial fossa through the superior orbital fissure, and its three terminal branches (lacrimal, nasociliary, and frontal nerves) are distributed throughout the orbit, anterior cranial fossa, anterior scalp, and nasal cavity. Other cranial nerves traverse the superior orbital fissure, including the oculomotor (CN III), trochlear (CN IV), and abducent (CN VI) nerves, to supply extraocular eye muscles. The superior orbital fissure also contains the superior and inferior ophthalmic veins and sympathetic fibers from the carotid plexus. With the broken pool cue residing in close proximity to the superior orbital fissure, the ophthalmic division of the trigeminal nerve is most likely damaged in this question.

Your 6-year-old patient is about to have his palatine tonsils removed. The surgeon will excise the tonsils that lie in the tonsillar bed between the _________ and __________ arches, and will need to excise the ____________fascia. Palatopharyngeal, glossoepiglottic, buccopharyngeal Palatopharyngeal, glossoepiglottic, pharyngobasilar Salpingopharyngeal, palatopharyngeal, pharyngobasilar Palatopharyngeal, palatoglossal, pharyngobasilar Salpingopharyngeal, palatoglossal, buccopharyngeal

The answer is palatopharyngeal, palatoglossal, and pharyngobasilar. The tonsillar bed lies between the palatoglossal and palatopharyngeal arches. The bed is formed by fibers of the superior constrictor and the pharyngobasilar fascia.

A 9-year-old girl with a history of strep throat has her palatine tonsils surgically removed. She returns to the hospital 3 days later with a high fever and chest pain. A physician orders a CT scan, which revealed spread of infection into the superior mediastinum. What is the most likely route for this infection to descend through the neck to reach the superior mediastinum? Suprasternal space Parapharyngeal space Carotid sheath Retropharyngeal space Buccal space

The answer is retropharyngeal space. The retropharyngeal space is the most frequent route for infection to spread through the neck into the superior mediastinum. This potential space exists between the prevertebral fascia and the anterior lamina of the prevertebral fascia, and it extends from the base of the skull to the superior mediastinum to the level of the third thoracic vertebra. The retropharyngeal space allows movement of the esophagus, pharynx, larynx, and trachea relative to the vertebral column, but it is clinically important due to its potential to provide a conduit for the spread of infection into the mediastinum.

A 24-year-old man came to his physician with a history of chronic maxillary sinusitis. A computed tomography (CT) scan reveals a soft-tissue mass in the superior aspect (or roof) of the right maxillary sinus. Functional endoscopic sinus surgery (FESS) was performed to biopsy the mass. Postoperatively, the patient experiences paresthesia and numbness of the skin of the right inferior eyelid and upper lip. Which nerve was most likely damaged during the surgery? Second division of trigeminal nerve Buccal branch of facial nerve Zygomatic branch of facial nerve Third division of trigeminal nerve First division of trigeminal nerve

The answer is second division of trigeminal nerve. The second (maxillary) division of the trigeminal nerve (CN V2) supplies the skin of the inferior eyelid and upper lip through the infraorbital nerve that courses through the superior aspect (roof) of the maxillary sinus, and due to its location, this nerve is most likely damaged during the biopsy. Damage to the infraorbital nerve causes paresthesia and numbness in the areas of cutaneous (sensory) distribution for this nerve.

The hypoglossal nerve and facial artery are found within the _____________. submental triangle. submandibular triangle. muscular triangle. occipital triangle. carotid triangle.

The answer is submandibular triangle. The submandibular triangle is bounded by the two bellies of the digastric and the inferior border of the mandible and contains the hypoglossal nerve, facial artery, and submandibular gland.

A male 1st-year medical student mistakenly enters the women's locker room and finds a group of his female colleagues changing their clothes. He is shocked and embarrassed by his mistake and immediately runs away with his heart pounding. Given his agitated state, what ganglion, housing neuron cell bodies, is experiencing an extremely high rate of activity? Ciliary ganglion Trigeminal ganglion Inferior (nodose) vagal ganglion Pterygopalatine ganglion Superior cervical ganglion

The answer is superior cervical ganglion. The student's reaction is a classic sympathetic "fight, fright, flight" response. All sympathetic fibers destined for the head synapse in the superior cervical ganglion. This ganglion marks the cranial end of the sympathetic chain, and is located near the base of the skull, at about vertebral level C2. Presynaptic neurons ascend through the sympathetic chain to the superior cervical ganglion. There, they synapse with postsynaptic neuron cell bodies that distribute their axonal processes throughout the head. These sympathetic fibers head control vasomotion, pilomotion, and sudomotion. Ciliary ganglion is incorrect. The ciliary ganglion is a parasympathetic ganglion, located in the orbit. The fibers that synapse in this ganglion supply the ciliary and sphincter pupillae muscles in the eye. It has no input into this sympathetic response. Trigeminal ganglion is incorrect. The trigeminal (semilunar) ganglion is a sensory ganglion. It houses the cell bodies of the pseudounipolar neurons carrying general sensory information from the trigeminal nerve (CN V). It has no input into this sympathetic response. Inferior (nodose) vagal ganglion is incorrect. The vagus nerve possesses two ganglia, superior and inferior, which are sensory ganglia. The superior vagal ganglion houses cell bodies of general sensory neurons. The inferior vagal ganglion houses the cell bodies of visceral afferent neurons. It has no input into this sympathetic response. Pterygopalatine ganglion is incorrect. The pterygopalatine ganglion is a parasympathetic ganglion, located within the pterygopalatine fossa. It sends fibers to the lacrimal gland and glands within the nasal cavity. It has no input into this sympathetic response.

A 40-year-old woman suffers from headaches, nausea, vomiting, and multiple lower cranial nerve involvement. Her physician orders a CT soft tissue neck study, and the given coronal CT shows a mass lesion (tumor) centered at the jugular foramen and identified by arrows. This tumor has destroyed the jugular foramen and hypoglossal canal on the right side and damaged the cranial nerves traversing these foramina. In this patient, which of the following functions will remain intact? Symmetric protrusion of the tongue Taste in the anterior two thirds of the tongue Control of the true vocal fold Elevation of the shoulder Sensation in the tympanic cavity

The answer is taste in the anterior two thirds of tongue. The chorda tympani nerve, a terminal branch of the facial nerve (CN VII), conveys taste sensation to the anterior two thirds of the tongue and carries presynaptic (preganglionic) parasympathetic fibers to the submandibular and sublingual glands to enable salivation. CN VII enters the skull through the internal acoustic meatus, and in this coronal CT, the margins of this foramen remain intact and are not involved in this presentation. Therefore, the tumor in the posterior cranial fossa is not currently affecting CN VII and its chorda tympani branch, which exits the skull via the petrotympanic fissure. This image shows a massive lesion within the right petrous temporal bone at the right jugular foramen with gross bone destruction. Involvement of the hypoglossal canal was also noted, though not shown on this particular CT. Therefore, the functions of the glossopharyngeal (CN IX), vagus (CN X), accessory nerve (CN XI), and hypoglossal (CN XII) nerves would be lost. Taste supplied to the anterior two thirds of the tongue by the chorda tympani nerve of CN VII would be the only function remaining intact. Control of the true vocal fold is incorrect. All of the intrinsic laryngeal muscles are controlled by branches of the vagus nerve (CN X). Specifically, all of these muscles are supplied by the recurrent laryngeal nerve of CN X, except for the cricothyroid muscle, which is innervated by the external laryngeal nerve off the superior laryngeal nerve of CN X. The pictured lesion has caused gross bone destruction within the right petrous temporal bone at the right jugular foramen. Therefore, the main stem of the vagus nerve is compromised at the right jugular foramen, causing loss of control and sensation in the entire right side of the larynx. Remember that the glossopharyngeal (CN IX), vagus (CN X), and (spinal)accessory (CN XI) nerves emerge from the cranium through the jugular foremen, and the given CT showed erosion of this bony canal by the invading tumor. Symmetric protrusion of the tongue is incorrect. The hypoglossal nerve (CN XII) innervates all of the intrinsic muscles of the tongue and most of its extrinsic muscles with the lone exception being the palatoglossus muscle, innervated by the vagus nerve (CN X). Therefore, damage to the right CN XII would produce ipsilateral deviation of the tongue during protrusion due to the unopposed muscular contractions of the contralateral genioglossus muscle. The mnemonic "The tongue licks the wound" will help you remember that the tongue deviates to the ipsilateral side in a lower motor neuron lesion of CN XII. A patient with a CN XII deficit would also display dysarthria and fasciculations within the tongue musculature, and the right CN XII would have been damaged in this patient due to the invading tumor destroying the hypoglossal canal, as noted in the clinical case. Sensation in the tympanic cavity is incorrect. Sensation from the walls of the tympanic (middle ear) cavity is carried by the branches of the tympanic nerve, a branch of the glossopharyngeal nerve (CN IX). This lesion has caused gross bone destruction at the right jugular foramen, resulting in damage to CN IX. The invading nature of this tumor would cause a sensory deficit in the right tympanic cavity. Remember that the glossopharyngeal (CN IX), vagus (CN X), and accessory (CN XI) nerves emerge from the cranium through the jugular foramen, and this tumor would lead to functional loss of these three cranial nerves. Elevation of the shoulder is incorrect. The (spinal) accessory nerve (CN XI) innervates the trapezius and sternocleidomastoid muscles. The trapezius elevates, retracts, depresses, and rotates the scapula. Thus, damage to CN XI at the jugular foramen results in notable deficits in shoulder action, including elevation. Remember that the glossopharyngeal (CN IX), vagus (CN X), and accessory (CN XI) nerves emerge from the cranium through the jugular foramen, and the given CT showed erosion of this canal by the invading tumor.

A 38-year-old man has had thyroid surgery to remove his papillary carcinoma. The external laryngeal nerve that accompanies the superior thyroid artery is damaged during the surgery. This injury could result in a severe impairment of function of which of the following? Rotating the arytenoid cartilages Widening the rima glottidis Abducting the vocal cords Tensing the vocal cords Relaxing the vocal cords

The answer is tensing the vocal cords. The external laryngeal nerve innervates the cricothyroid muscle (major tensor), which tenses the vocal cord. The anterior part of the vocalis muscle can tense the vocal cord, and its posterior part can relax the vocal cord. The lateral cricoarytenoid muscle rotates the vocal process of the arytenoids cartilage medially, closing the rima glottides. The rima glottidis is opened (widened) by rotating the vocal process of the arytenoid cartilage laterally by the posterior cricoarytenoid muscle. Other laryngeal muscles adduct the vocal cords.

You are examining a 25-year-old patient in the ED after he was involved in a motorcycle accident in which he was not wearing a helmet. Fluid is leaking from his right nostril and he cannot smell on that side. Which of the following osseous structures is most likely fractured? Choanae Nasal bones Perpendicular plate of ethmoid Sella turcica Cribriform plate

The answer is the cribriform plate. The cribriform plate forms the roof of the cranial cavity and the olfactory nerves pass through it to synapse in the overlying olfactory bulb. Fracture of the plate results in CSF dripping from the nose.

Following a procedure to remove the thyroid gland (thyroidectomy), a surgeon reports the right recurrent laryngeal nerve was incised accidentally. Which of the following muscles would continue to function despite this iatrogenic damage? Posterior cricoarytenoid Lateral cricoarytenoid Thyroarytenoid Cricothyroid Thyroepiglottic

The answer is the cricothyroid. The cricothyroid muscle tenses the vocal cords. It is the only listed intrinsic muscle of the larynx that is not innervated by the recurrent laryngeal nerve. The cricothyroid muscle is innervated by the external laryngeal nerve, a terminal branch of the superior laryngeal nerve. Because the cricothyroid muscle is innervated by the external laryngeal nerve, it would continue to function despite the damage to the right recurrent laryngeal nerve in this patient. Posterior cricoarytenoid is incorrect. The posterior cricoarytenoid muscle is the only intrinsic muscle of the larynx which abducts the vocal cords. Because it is innervated by the recurrent laryngeal nerve, it would not function following the listed iatrogenic damage. Lateral cricoarytenoid is incorrect. The lateral cricoarytenoid muscle adducts the vocal cords by rotating the arytenoid cartilage. Because it is innervated by the recurrent laryngeal nerve, it would not function following the listed iatrogenic damage. Thyroarytenoid is incorrect. The thyroarytenoid (vocalis) muscle relaxes the vocal cords. Because it is innervated by the recurrent laryngeal nerve, it would not function following the listed iatrogenic damage. Thyroepiglottic is incorrect. The thyroepiglottic muscle widens the laryngeal inlet by pulling the aryepiglottic folds apart. Because it is innervated by the recurrent laryngeal nerve, it would not function following the listed iatrogenic damage.

A 34-year-old man visits his physician complaining of abnormal sensations and numbness in his upper teeth and in the skin of his lower eyelid, cheek, upper lip, and lateral external nose on his left side. Which of the following cranial openings is the most likely site for the nerve lesion responsible for these signs and symptoms? Foramen spinosum Superior orbital fissure Foramen rotundum Foramen ovale Jugular foramen

The answer is the foramen rotundum. The foramen rotundum is located in the greater wing of the sphenoid bone and transmits the maxillary (second) division of the trigeminal nerve (CN V2). This maxillary nerve enters the middle cranial fossa after leaving the pterygopalatine fossa. The maxillary nerve supplies the upper teeth (dentition), and one of its terminal branches, the infraorbital nerve, supplies the skin of the lower eyelid, cheek, upper lip, and lateral external nose.

A 42-year-old man suffers from a rare tongue disease and comes to the emergency department. On examination, he is unable to protrude his tongue. Which of the following muscles is paralyzed? Genioglossus Palatoglossus Geniohyoid Styloglossus Hyoglossus

The answer is the genioglossus. The genioglossus protrudes the tongue. The hyoglossus and styloglossus muscles retract the tongue. The palatoglossus elevates the tongue. The geniohyoid elevates the hyoid bone and the floor of the mouth.

Your 56-year-old patient has dysphagia (trouble swallowing) that you believe is neural in origin. Which of the following nerves is least likely to have an effect on deglutition? Internal laryngeal External laryngeal Hypoglossal Glossopharyngeal Pharyngeal branches of vagus

The answer is the internal laryngeal nerve. The internal laryngeal nerve is a purely sensory nerve that supplies the upper part of the larynx. All the other nerves innervate muscles involved in swallowing.

During a routine eye exam, the ophthalmologist noted the direct and consensual light reflexes of his patient were absent when he shined a flashlight in the right eye. Because the doctor found no problem with the visual acuity (eyesight) of the patient, which cranial nerve is most likely damaged in this patient? Optic nerve Trigeminal nerve Oculomotor nerve Trochlear nerve Abducent nerve

The answer is the oculomotor nerve. The oculomotor nerve (CN III) innervates the constrictor pupillae muscle of the iris, which is responsible for constricting the pupil, and this muscle is supplied by the parasympathetic component of the oculomotor nerve. The physician is performing the pupillary light reflex that tests the integrity of the optic nerve (CN II), which is the afferent limb of this reflex, and the oculomotor nerve, which is the efferent limb. Because the eyesight of the patient is normal, CN II is intact. However, the absence of the direct and consensual light reflexes implies damage to the oculomotor nerve because of failure of the constrictor pupillae muscle of the iris to contract.

A 55-year-old man consulted his family physician about a swelling antero-inferior to his left ear. At the exam, he also complained that the left side of his face felt weak and the corner of his mouth was drooping. On examination, the physician detected a hard mass deep within the substance of the parotid gland. He also observed that the man's facial muscles on the left side were weaker than on the right side. Which of the following statements best describes the most likely cause of the patient's complaints? Compression of the auriculotemporal nerve Compression of the external carotid artery Compression of the otic ganglion The parotid plexus of the facial nerve (CN VII) was being compressed by a carcinoma of left parotid gland. Compression of the trigeminal ganglion

The answer is the parotid plexus of the facial nerve (CN VII) was being compressed by a carcinoma of left parotid gland. The damaged CN VII caused the weakness of the facial muscles on the left side and the sagging of the left corner of his mouth. Compression of the trigeminal ganglion is incorrect. This ganglion is not in the parotid gland, and compression would not cause weakness in the facial muscles. Compression of the auriculotemporal nerve is incorrect. This nerve carries parasympathetic fibers that innervate the parotid gland, but compression would not cause facial muscle weakness. Compression of the otic ganglion is incorrect. This ganglion is not in the parotid gland and compression would not cause facial muscle weakness. Compression of the external carotid artery is incorrect. This artery traverses the parotid gland, but compression is unlikely to cause facial muscle weakness.

Your 17-year-old patient is frustrated because every time she ingests any food that is very cold, especially ice cream, she gets a headache. Such patients are believed to have a very sensitive parasympathetic ganglion that is located directly superior to the posterolateral aspect of the hard palate. What is this ganglion? Superior cervical Geniculate Pterygopalatine Submandibular Otic

The answer is the pterygopalatine. The pterygopalatin ganglion is located in the pterygopalatine fossa, directly superior to the hard palate and in some people is believed to be very sensitive to cold.

A 56-year-old woman reports difficulty with diplopia (double-vision) when descending stairs. During an eye-movement exam, her right eye was unable to look downward when her eye was adducted (or in a medial position). Which of the following cranial nerves is most likely damaged in this patient's right eye? Facial nerve Trochlear nerve Oculomotor nerve Trigeminal nerve Abducent nerve

The answer is the trochlear nerve. The trochlear nerve (CN IV) innervates only one muscle, the superior oblique, located in the orbit. Acting individually, this muscle pulls the eye inferolaterally, but it is difficult to distinguish this movement from the combined movements of the inferior rectus and the lateral rectus muscles, which move the globe inferior and lateral, respectively. Therefore, the right trochlear nerve is clinically tested by asking the patient to look inferiorly after the right eye is placed in an adducted position. Patients with damage to the trochlear nerve often report diplopia when descending stairs.

Genetic testing of a baby boy with facial and cardiovascular anomalies reveals a small deletion in chromosome 22, specifically 22q11.2. This 22q11.2 deletion (DiGeorge) syndrome often results in migration defects of neural crest cells within the pharyngeal pouches. In this DiGeorge syndrome patient, the thymus and inferior parathyroid glands are absent. Which of the following pharyngeal pouches is most likely affected? Fourth Fifth First Third Second

The answer is third. The thymus and inferior parathyroid glands are derived from the third pharyngeal pouch. Therefore, migration of neural crest cells into the third pharyngeal pouch has been diminished in this patient with DiGeorge (22q11.2 deletion) syndrome. The patient would present with immunodeficiency due to an absence of the thymus, and hypocalcemia (low blood calcium levels) due to the absence of inferior parathyroid glands. DiGeorge syndrome is also characterized by conotruncal hearts defects, such as tetralogy of Fallot or interrupted aortic arch. Moreover, facial anomalies usually resemble first arch syndrome with the patient presenting with a hypoplastic mandible, low-set ears, hypertelorism (increased distance between the eyes), and microstomia (abnormally small mouth). First is incorrect. Evagination of the first pharyngeal pouch forms an elongated diverticulum off the pharynx (the tubotympanic recess). The distal part of this recess widens to form the tympanic (middle ear) cavity. The proximal part remains more tubular and forms the pharyngotympanic (auditory; eustachian) tube. Therefore, agenesis of the thymus and inferior parathyroid glands is not due to maldevelopment of the first pharyngeal pouch. Second is incorrect. The second pharyngeal pouch helps to form the tonsillar fossa and surface epithelium of the palatine tonsil. Secondarily, lymphatic tissue, which becomes the palatine tonsils, is incorporated into the second pharyngeal pouch. Maldevelopment of the second pharyngeal pouch does not cause agenesis of the thymus and inferior parathyroid glands. Fourth is incorrect. The fourth pharyngeal pouch forms the superior parathyroid gland and the ultimobranchial body, which gives rise to the parafollicular (C) cells of the thyroid gland. Maldevelopment of the fourth pharyngeal pouch does not cause agenesis of the thymus and inferior parathyroid glands. Fifth is incorrect. The fifth pharyngeal pouch only exists transiently in human embryologic growth and development. No adult structures are derived from the fifth pharyngeal pouch, so this option can be easily eliminated.

Your 80-year-old patient just had an embolic event that occluded all blood flowing in the central artery of the retina in her right eye. What did your patient complained of? Diplopia Partial blindness in her right eye Total blindness in her right eye Itchy discomfort in her cornea Dry eye

The answer is total blindness in her right eye. The central artery of the retina provides the only blood supply to the internal aspect of the retina. Total occlusion results in total blindness.

The superior sagittal sinus contains mostly ______________. arterial blood. cerebrospinal fluid. venous blood. air. mucous.

The answer is venous blood. The superior sagittal sinus is a dural sinus. Dural sinuses are essentially large valveless veins within the cranial vault.

A 60-year-old female yodeler with a 43-year history of smoking complains of pain during swallowing and hoarseness in her voice. A fiberoptic endoscopy reveals a laryngeal squamous cell carcinoma at the location identified by the arrow within the given figure. What structure is most likely affected by this laryngeal cancer? Epiglottis Infraglottic cavity Laryngeal vestibule Vestibular folds Vocal folds

The answer is vocal folds. The squamous cell carcinoma is identified on the mucosal surface at the inferiomedial border of the laryngeal ventricle, which would be the location of the vocal cords. The most common presenting symptom in laryngeal cancer, particularly in glottic tumors such as this one, is hoarseness of the voice while some people experience odynophagia (painful swallowing).

A 25-year-old man is having surgery to repair a severely deviated nasal septum that has contributed to severe nasal congestion. This will mean a surgical procedure that could alter the shape of all of the following cartilages or bones except: Sphenoid Septal cartilage Vomer Perpendicular plate of ethmoid Lateral cartilages of nose

sphenoid bone is not part of the nose