Anatomy Head and Neck Multiple Choice

After undergoing a parotidectomy, a 34-year-old man experiences redness and sweating of the temples when eating. These symptoms occur because of connections formed between the postganglionic parasympathetic fibers to the gland and nerves that supply the sweat glands of the overlying skin. Which of the following pairs of nerves is involved?

Auriculotemporal-great auricular

A 20-year-old man presents with loss of taste sensation on the anterior two thirds of his tongue. He also reports a feeling of dryness in the mouth (xerostomia). Examination reveals that secretion from the submandibular and sublingual salivary glands is greatly reduced. Taste on the posterior one third of the tongue remains intact, as does general sensation on the entire tongue. No other defects are noted. What nerve injury would account for this clinical picture?

Chorda tympani injury in the middle ear

A 26-year-old man is brought to the emergency department after a high-speed car crash in which he suffered head trauma. A CT scan of the head shows a basilar skull fracture involving the foramen rotundum. Identify the structure that would most likely be damaged due to injury to the foramen rotundum.

Maxillary nerve

A colloid cyst is a type of slow-growing non-neoplastic cyst that is found near the center of the brain. These cysts can often grow to cause obstruction of the foramen of Monro, leading to hydrocephalus. Based on this location of obstruction, in which ventricular chamber would there be a buildup of cerebrospinal fluid (CSF)?

Lateral ventricle

A 15-year-old boy was attacked and severely beaten about the head. Computed tomography (CT) scans revealed a fracture of the petrous portion of the temporal bone. What is the most likely consequence of such a fracture?

Bleeding from the ear

An 83-year-old man suffers a stroke to the left facial motor nucleus of the pons, resulting in the paralysis of facial nerve. Which of the following motor deficits does he likely experience?

Left corner of the mouth droops when smiling

A 45-year-old man presents with loss of sensation in his lower lip, chin, and jawline. A new resident ordered at CT scan, which revealed no cortical damage. Based on the symptoms, you suspect damage to one of the cranial nerves. Identify the cranial nerve that is most likely damaged in this patient.

CN V

A 4-week-old infant is brought to her pediatrician because of poor feeding, irritability, and frequent vomiting. Examination reveals that her head circumference falls in the 99th percentile for her age, dilated veins are easily visible in her scalp, and her anterior fontanelle is tense and bulging. After appropriate imaging studies, a diagnosis of congenital hydrocephalus is made. A physician tells the parents that as the baby gets older, without appropriate treatment, the part of the skull formed from anterior fontanelle closure would be malformed. In her notes, the physician uses the medical term for this adult skull region. Which of the following correctly describes this location?

Bregma

A 14-year-old boy has become totally deaf in his left ear after a motor vehicle accident. Hearing in his right ear is normal. A lesion at which of the following sites is the most likely cause of this finding?

Left posterior and anterior cochlear nuclei

After suffering a stroke, a 67-year-old woman describes symptoms localized to her right side consisting of pain along with difficulties in sensation of touch and temperature. Which of the following brain regions is most likely affected by the stroke?

Left thalamus

A 73-year-old woman presents with the following symptoms: left progressive hearing loss, unsteady gait, vertigo, and left-sided facial weakness. On physical examination, she is also found to have decreased sensation over the left side of her face. As part of her evaluation, this woman's physician orders an MRI (magnetic resonance imaging) scan, which shows a lesion consistent with an intracranial tumor. What is the most likely location of this lesion?

Cerebellopontine angle

A 14-year-old boy developed a slowly enlarging, painless swelling in the neck along the anterior border of the sternocleidomastoid muscle, near the inferior angle of the mandible. He was diagnosed with a branchial cyst, which was surgically removed. A branchial cyst is a remnant of which of the following?

Cervical sinus

A 23-year-old patient was admitted to the emergency department with a laceration injury to the top of the head. The injury was deep enough to penetrate the muscular aponeurotic layer of the scalp but did not affect any layer below it. Which of the following layer(s) remained before the laceration would have reach bone?

Loose connective tissue layer and periosteum

A 65-year-old woman comes to the emergency department complaining of difficulty swallowing and pain in the back of her throat. She had a fishbone "stuck in her throat" about 5 days earlier. She has had subjective fevers and malaise. On physical exam a submucosal mass is visible protruding into the back of her throat. A lateral radiograph of the neck reveals anterior displacement of the esophagus and trachea by a mass in the posterior pharynx. This mass contains air bubbles. What is the most likely diagnosis?

Abscess in the retropharyngeal abscess space

A 20-year-old college student suffers a C3 spinal cord injury as a result of a trampoline accident. He is quadriplegic and in respiratory distress and is initially placed on a respirator. Several months later he is surgically implanted with a phrenic nerve pacemaker, which stimulates his phrenic nerve in a rhythmic pattern, resulting in contraction of the diaphragm that mimics normal breathing. At which site could a surgeon access this nerve to attach the stimulating electrode to it?

Anterior to the anterior scalene muscle

A 44-year-old woman is scheduled to undergo liposuction to remove deposits of adipose tissue in her neck. Injection of local anesthetic into one location will result in significant anesthesia of most of the skin of the neck. Which of the following would be the best location?

At the midpoint of the posterior border of sternocleidomastoid

A 35-year-old man presents to the emergency department with a fractured mandible after a bar fight. After the mandibular reconstruction surgery, the patient is noted to have loss of sensation in his lower lip. After further testing, it is determined that the patient has damage to the mandibular branch of his trigeminal nerve. Which of the following symptoms would also likely fit this diagnosis?

Loss of sensation in the tip of the tongue

A mucoepidermoid carcinoma of the parotid gland is found to have infiltrated the chorda tympani nerve, compromising its function. Which of the following deficits would likely result from the loss of function of this nerve?

Loss of taste on anterior two thirds of tongue

Uveitis is an inflammatory condition of the uveal coat of the eye that is often associated with systemic inflammatory disorders. Uveitis can be further specified as anterior, intermediate, posterior, or panuveitis based on the areas of the urea affected. Which of the following structures of the uvea would most likely be affected in posterior uveitis?

Choroid

A 5-year-old girl presents with symptoms of frequent headaches, nausea, vomiting, and sleepiness that have been gradually been getting worse over the past month. The patient's mother also reports a notable decrease in her child's visual acuity over this time period. Physical exam of the patient reveals homonymous visual field defects and papilledema. Upon further investigation, a brain MRI shows a tumor involving a structure located in the left lateral ventricle that is causing increased cerebrospinal fluid (CSF) production. Based on the anatomical location and presentation of the tumor, which of the following structures is the tumor most likely involving?

Choroid plexus

A resident performing a neurological exam wants to test the pons. Identify the reflex most likely used.

Corneal reflex

A 29-year-old woman sustains a traumatic head injury after falling from a 20-foot cliff face while rock climbing without a harness. Fortunately, she was not climbing alone, and her friends were able to contact emergency services relatively quickly. After being transported by the emergency helicopter to the hospital, she underwent a diagnostic CT scan followed by a MRI of the skull. These scans revealed the presence of a penetrating lesion of the white matter tract that connects the two hemispheres of her cerebrum, also known as "split-brain." Once the patient is stabilized, the attending neurologist explains to the patient's family that some functions of the brain that are lateralized, like language and facial recognition, may show some deficits because the two hemispheres of the brain can no longer communicate. Which of the following white matter tracts of the brain is most likely severed in this patient?

Corpus callosum

A 45-year-old man presents with a chief complaint of progressive hearing loss and dizziness. His history reveals a long career in the boxing industry, in which he sustained many blows to the head over his lifetime. You fear that he has incurred some cell loss in certain areas of his brain. Which of the following areas of cell loss would explain your patient's hearing difficulty?

Corti ganglion

A 22-year-old woman is referred to an otolaryngeal clinic because of recurrent rhinitis and associated stuffiness in her right nostril. On examination it is noted that the patient has slight tenderness medial to and below the medial cants of the eye. A computed tomography (CT) scan of the head is ordered, which demonstrates a polypoid growth arising from the mucosa lining the ethmoidal air cells. The polyp is removed by functional endoscopic sinus surgery (FESS). Three weeks after the surgery the patient returns to the clinic complaining of a clear, yellow-tinged nonclotting fluid running from her nose. Damage to which of the following structures is the most likely cause of this new complaint?

Cribriform plate

A 54-year-old man is undergoing a routine physical examination when the physician discovers that the man has an enlarged thyroid. An MRI scan shows a mass in the left lobe of the thyroid. During the thyroidectomy, the recurrent laryngeal nerve is injured. Which of the following intrinsic muscles of the larynx would be spared?

Cricothyroid

To decompress the stomach, a nasogastric tube must be passed and connected to suction. The tube goes into one of the nares, traverses the nasopharynx into the esophagus, and then passes into the stomach. To avoid trauma to the nasopharynx, in what direction should you angle the tip of the tube as you pass it into the nares?

Directly posterior, along the floor of the nasal cavity

A 57-year-old man sustains facial trauma during an altercation. Examination reveals bruising around the left orbit with subconjunctival hemorrhage. The pupils are equal, round, and appropriately reactive. Eye movements are normal in all directions except up, producing diplopia on upward gaze. The eye on the injured side does not move upward to follow a target moved by the examiner. Computed tomography shows an orbital floor fracture on the left, with soft tissue within the fracture site. Which of the following is the most likely explanation?

Entrapment of the inferior rectus muscle at the fracture site

A 12-year-old patient presents with facial burns that have blistered after extended sun exposure. The attending physician diagnoses them as second-degree burns. The grading of burns is dependent on the depth of the burn relative to the layers of the skin. A first-degree burn is considered a superficial burn, while a second degree burn is slightly deeper involving another layer of the skin. What layer(s) of skin have likely been damaged in this patient?

Epidermis and dermis

A 45-year-old man complains of facial paralysis. Physical examination shows a partial ptosis of the left eyelid, weeping from the left eye, drooping of the left corner of the mouth, and failure of that corner of the mouth to respond when the man smiles. Injury to which of the following cranial nerves would produce the symptoms in this patient?

Facial (CN VII)

A 10-year-old boy presents with a rare aggressive soft tissue tumor in the orbit of the eye that requires excision. During the procedure the surgeon unintentionally nicks the ophthalmic artery. She immediately clamps the ophthalmic artery to control the bleeding. Which of the following areas will temporarily lose blood supply as a result of this clamping?

Forehead

A 31-year-old woman presents with a throbbing pain and a feeling of pressure in her forehead above her eyebrows. Examination reveals an infection of the sinus in this region. Which paranasal sinus is most likely infected, causing pain in the region the patient describes?

Frontal Sinus

During extraction of an impacted last lower molar tooth, a patient suffers damage to the nerve that travels between the medial pterygoid muscle and mandible and below the molar. When anesthesia wears off, the patient still reports lack of general sensation on half the tongue ipsilateral to the molar tooth that was extracted. This nerve contains which of the following functional components?

General somatic afferent (GSA) fibers, special visceral afferent (SVA) fibers, general visceral efferent (GVE) fibers

A 57-year-old man who has smoked cigarettes for 40 years has a small lump in the submental triangle. On palpation, the lump appears to be a single hard nodule; it is mobile and not tethered to skin. The preliminary diagnosis is a secondary malignancy of a submental lymph node. A primary malignancy would most likely be located in which of the following areas?

Gingiva of the lower incisors

A 43-year-old patient sees his doctor because of loss of bitter and sour taste on the back third of his tongue and trouble swallowing. Identify the cranial nerve most likely to be injured in this patient.

Glossopharyngeal (CN IX)

A 20-year-old man becomes ill with a high-grade fever, severe headache, and malaise. His physician prescribes antibiotics, but the man's condition worsens. He develops chills, nausea, vomiting, and episodes of delirium. His eyes ache and he develops an internal strabismus. The diagnosis is cavernous sinus thrombosis. Which venous structure is unlikely to seed the cavernous sinus with infectious material?

Great cerebral vein

An experienced surgeon is delicately removing an adenocarcinoma in the submandibular triangle. He dissects away the subcutaneous fat and identifies the cancerous tissue, and then identifies the local neurovascular structures that he wants to preserve in the surrounding area. The surgeon finds the facial vein and the facial artery but has trouble finding the nerve that also passes near the submandibular gland. Which of the following nerves is the surgeon likely trying to identify?

Hypoglossal

An 18-year-old man was involved in a fistfight that resulted in a medial orbit blowout fracture of his face and a subsequent trip to the emergency department. The attending physician is worried about a nasolacrimal duct obstruction due to the location of the fracture, so he decides to run an irrigation test to determine if the duct is still patent. If fluid is irrigated through a cannula in the lacrimal punctum, where should the fluid end up draining if the duct is still patent?

Inferior nasal meatus

A 21-year-old man sustained a laceration wound to his upper lip from a fall he had while celebrating his 21st birthday. After suboptimal care for the cut, the wound became infected as evidenced by redness, warmth to the touch, and swelling around the area of the cut. The patient believed it was a minor infection and neglected to seek medical attention. Several days following the infection, the patient presented to the emergency department demonstrating symptoms of cavernous sinus syndrome, an infection of the cavernous sinus through which passes many important structures. In your assessment of the etiology, you surmise that a retrograde infection had spread from his facial laceration to his cavernous sinus. Through which of the following structures did the infection likely spread to this patient's cavernous sinus?

Inferior ophthalmic vein

To secure the airway during surgery, an anesthesiologist must pass an endotracheal tube through the vocal folds into the trachea of an anesthetized patient. The anesthesiologist visualizes the epiglottis with a laryngoscope. Where are the vocal folds and therefore the entrance to the trachea found?

Inferior to the epiglottis

A 50-year-old man is attacked by a knife-wielding assailant. He sustains a deep laceration to the lateral aspect of his face. He is seen in the emergency department approximately 1 hour after the event. He is noted to have an approximately 4-cm long oblong gash beginning at the tragus of the left ear and progressing medially and inferior toward the left commissure of the lip. Sensation is diminished along a strip of skin medial to the laceration for about 2 cm. What is the most likely diagnosis?

Injury to the mandibular division of the trigeminal nerve

A 57-year-old man sees a neurologist for a 6-month history of significant weight loss and difficulty swallowing. On examination, he is noted to have an absent gag reflex and difficulty elevating his shoulders and turning his head against resistance. In light of the significant weight loss, the neurologist feels that this man may have a malignant brain tumor. A tumor at what cranial foramen would cause these findings?

Jugular foramen

A 63-year-old man presents with a thrombosis that is occluding his right external carotid artery. He displays symptoms of decreased blood flow to his right face, with an absent facial artery pulse in his right occipital region, the area behind his ear, his right temporal region, and the deep structures of the right face normally supplied by the maxillary artery. Based on the symptoms and vessels receiving decreased blood flow, where is the occlusion on the external carotid artery?

Just below the facial artery

A 24-year-old woman has severe pain in her jaw, which she thinks resulted from excessive yawning. Physical examination indicates dislocation of the temporomandibular joint. This injury would most likely be caused by contraction of which of the following muscles?

Lateral pterygoid

A 91-year-old woman suffers a stroke and is seen in the emergency department. An MRI shows damage to the right trigeminal motor nucleus. Which of the following muscles is most likely affected by the damage in this patient?

Lateral pterygoid muscle

A 28-year-old man presents with recurrent sinusitis infections that have been causing severe discomfort, with headaches and pressure under his left cheek. A CT scan is indicated due to the frequency of his infections and the severity of his current infection. After analysis of this patient's CT scan, the diagnosis of sinusitis is confirmed with the visualization of a completely filled right-sided cavity corresponding to the area under his left orbit where the pressure is localized. Which of the following paranasal sinuses is most likely infected in this patient?

Maxillary sinus

A 23-year-old man presents to the emergency department with knife lacerations to the face. One laceration is a deep wound to the superior aspect of the chin. Identify the artery most likely damaged by this lesion.

Mental Artery

A 65-year-old man who is right handed has had a stroke. Although his speech is fluid and melodic and he articulates well, he makes little sense and uses few meaningful words. He is unable to name common objects and does not seem to understand the physician's questions. He has diminished sensation in his right arm and hand. This patient's stroke has most likely affected which of the following arteries?

Middle cerebral

Acromegaly is a hormonal condition in which the anterior pituitary gland produced too much growth hormone, causing some bones to increase in size, namely the bones of the face, hands, and feet. This gland can be found in which of the following cranial fossae?

Middle cranial fossa

A 46-year-old patient receives an iatrogenic injury to her superior cervical ganglion during a surgical procedure in that region. Which of the following symptoms is most likely to occur?

Miosis

A pleomorphic adenoma is discovered in the sublingual gland of a 53-year-old patient with a long history of using chewing tobacco. He complains of some xerostomia, dryness of the mouth caused by the lack of saliva production, and discomfort resulting from the presence of a mass under his tongue. The sublingual gland acini cells are primarily responsible for producing which of the following components of saliva?

Mucus

A 27-year-old mother presents to the pediatrics clinic with difficulty breastfeeding her new baby. She notes that her nipple becomes erect from stimulation from the baby, but milk does not come out. After an extensive workup, it is found that the mother's hypothalamus is not producing adequate amounts of oxytocin. Identify the correct cellular target and function of oxytocin in a normal patient.

Myoepithelial cells, muscle contraction

Internuclear ophthalmoplegia (INO) is a medical condition that affects conjugate lateral gaze. The affected eye will display difficulty in adduction when gaze is directed in the contralateral direction (for example, if the left eye is affected, there is minimal adduction when looking to the right). Identify the nerve and muscle pair that would be responsible for abnormal eye movement.

Oculomotor, medial rectus

A 6-year-old boy presents to the emergency department with difficulty breathing, stridor, and constellational symptoms associated with a severe acute tonsillitis. A throat (oropharynx) swab is taken, and a rapid strep test confirms an infection caused by Streptococcal pyogenes. Examination of his throat through an open mouth view reveals significantly enlarged hypertrophic tonsils that are actually contacting each other, referred to as "kissing tonsils," obstructing this child's airway. Identify the tonsils that are likely the enlarged and hypertrophied tonsils seen at the back of the patient's throat.

Palatine tonsils

A physical examination of a 3-year-old girl with recurring otitis media shows that she has a poorly draining auditory tube. This condition is caused by hypertrophy of which of the following structures?

Pharyngeal tonsil

A tympanostomy tube placement is recommended to patients with recurrent otitis media, or infections of the middle ear. This surgical placement is recommended to prevent the accumulation of fluid in the middle ear, subsequently relieving pressure on the tympanic membrane. Which of the following structures of the middle ear is blocked in these patients?

Pharyngotympanic (eustachian) tube

A 45-year-old man develops increasingly severe headaches, which often awaken him from sleep at night. Physical examination is normal with the exception of bitemporal hemianopsia. What is the most likely diagnosis?

Pituitary adenoma

A 31-year-old woman undergoing surgery to resect a laryngeal tumor is having difficulty coming off the mechanical ventilator post operation. She was initially extubated in the operating room after the procedure, but showed immediate signs of respiratory distress and was thus re-intubated. After workup of the laryngeal musculature, it is noted that her vocal cords are stuck in the adducted position and she cannot provide any abduction. Which of the following muscles is most likely paralyzed, preventing abduction of the vocal folds?

Posterior crico-arytenoids

A 40-year-old man with neck pain and swelling is diagnosed with tuberculosis of the spine (tuberculous spondylitis, or Pott disease) in the cervical region. His infection has resulted in abscess formation. The pus was originally contained within the layer of deep cervical fascia that surrounds the vertebral column and its associated muscles. With time, it has spread laterally within this compartment, pointed (i.e., come to a head), and ruptured through the fascia to enter the posterior cervical triangle. There it has formed an obvious swelling on the side of the neck. Which is the layer of fascia that originally confined the abscess?

Prevertebral fascia

A 23-year-old baseball pitcher sustained a traumatic blow to the head from a baseball that was hit directly back at him. He was immediately taken to the hospital and had a CT scan that revealed an epidural hematoma caused by the rupture of his left middle meningeal artery. On the basis of the bony anatomy of the skull and its relation to the middle meningeal artery, the baseball most likely struck which of the following locations?

Pterion

A 29-year-old man is found to have a tumor that is compressing the right hypoglossal canal at the base of the skull. Which of the following deficits would the patient most likely be displaying if the structure exiting the canal were impinged?

Right-sided tongue deviation when asked to protrude the tongue

A 21-year-old man is referred to an otolaryngologist by his family physician because of a chief complaint of hoarseness and a rough sound to his voice that has persisted for approximately a week. His problems began the morning after a concert—he is the lead singer of his rock band—and have been present ever since. He reports no illnesses in the past 6 months and displays no signs of current infection. When asked, he stated that he smokes cigarettes occasionally at his concerts but not regularly. Based on this information and physical exam, a laryngoscopy is performed. His vocal cords show bilateral swelling, causing the space between the vocal cords to be smaller than normal at rest. A diagnosis of Reinke's edema is made. What is the name of the space that is narrowed due to edematous swelling in this patient?

Rima glottides

A 2-year-old girl is brought to her pediatrician because of a middle ear infection that has not resolved despite antibiotic treatment. The child now has a discharge from the ear (otorrhea), fever, and tenderness, redness, and swelling posterior to her ear. A CT scan shows that the infection has spread from the middle ear to the mastoid air cells. This infection has the potential to erode through bone and invade a dural venous sinus located just posterior to the mastoid air cells. Which dural venous sinus is this?

Sigmoid sinus

A 47-year-old man presented with complaints of headache and blurred vision. Initial examination was inconclusive. He returned several days later with ptosis, diplopia, and nuchal rigidity. CT scans revealed an isolated infection of one of the sinuses that appears to have eroded through the walls of the sinus, endangering the cavernous sinus, pituitary, optic nerves, optic chiasm, and meninges. Which of the following sinuses is most likely affected in this patient?

Sphenoid sinuses

An 18-year-old man presents to the emergency department because of epistaxis (nosebleed) and blood draining down the throat after being hit in the face by a hockey puck. The physician determines that the nose is fractured, but he is more concerned about stopping the bleeding. Further examination reveals that this is a posterior epistaxis, meaning that one of the vessels in the posterior aspect of the nasal cavity is actively bleeding. Which of the following vessels is most likely ruptured in this patient?

Sphenopalatine artery

A 35-year-old patient presents to the emergency department after blunt force trauma to the right side of her skull. After the patient was stabilized, she underwent a neurological exam, revealing hyperacusis (louder than normal sound) of the right ear, right-sided facial paralysis, and difficulty tasting on the anterior portion of her tongue. Imaging reveals a fracture of the temporal bone that most likely severed the facial nerve. Which of the following is most likely not functioning properly and the cause of the hearing problem in this patient?

Stapedius muscle

Cauliflower ear is a condition usually caused by blunt force trauma to the external ear, often experienced by boxers and wrestlers. The trauma causes the overlying cartilage to separate from the perichondrium that supplies the blood and nutrients to the external ear. Due to the lack of nutrients and blood supply, areas of the external ear die and become fibrotic, resulting in a swollen and deformed ear that looks like cauliflower. Which of the following arteries most likely loses its ability to supply part of the external ear in these patients?

Superficial temporal artery

A 67-year-old man presents with an arterial thromboembolism that has occluded his superior thyroid artery just after its branch point from the external carotid artery. Among other symptoms, this ischemic event has resulted in hoarseness of his voice. Which of the following branches of the superior thyroid artery is most likely occluded, resulting in ischemic damage within the larynx causing themhoarseness?

Superior laryngeal artery

After several episodes of tonsillitis over the past 4 months, an 11-year-old boy undergoes a tonsillectomy. Microscopic section of the palatine tonsil shows skeletal muscle. Which muscle is most likely to be the source of this specimen?

Superior pharyngeal constrictor

A 39-year-old patient is suffering from Sjögren's syndrome, an autoimmune disease characterized by the destruction of exocrine glands that produce tears and saliva, resulting in keratoconjunctivitis and xerostomia, respectively. She is particularly irritated by her dry eyes and wants an explanation of why this disease causes this problem. You explain to her the normal function of the lacrimal gland in the production of the tears needed to keep the eye lubricated. She asks you where this gland is located in the orbit, and you respond:

Superolateral aspect of the orbit

A 55-year-old man is the unrestrained driver of a motor vehicle involved in a crash at highway speeds. He is ejected from the vehicle and sustains multiple injuries including facial trauma, pelvic fracture, and ruptured spleen. Computed tomography of his brain and skull shows factures of the nasal bones including bilateral cribriform plate fractures. Which sense is likely to be diminished following this particular injury?

smell

A 45-year-old man has a persistent cough and is unable to completely open his right eye. Further examination of the right side of the face indicates that the face feels flushed and warm to the touch, and he has miosis and enophthalmos. A chest radiograph shows an apical tumor of the right lung. Which of the following structures is most likely affected by the tumor?

Thoracic sympathetic chain

A 55-year-old woman complains of bone pain and has suffered several pathological bone fractures. She is diagnosed with primary parathyroidism and is scheduled for exploratory surgery with resection of abnormal glands. During the operation the surgeon is unable to locate the inferior parathyroid glands in their usual location. He searches for ectopic parathyroid tissue based on his knowledge of the embryological origin of the parathyroids. Which structure is derived from the same pharyngeal pouch as the inferior parathyroids and is a likely location for ectopic parathyroid tissue?

Thymus

While driving an all-terrain vehicle, a 19-year-old man is injured by a low hanging branch, receiving a horizontal blow across the anterior aspect of the neck (a "clothesline" injury) at the level of the C5 vertebra. He develops dyspnea (difficulty in breathing) and dysphonia (difficulty in speaking). Which structure is most likely to have been injured by a blow at the C5 level resulting in the observed symptoms?

Thyroid cartilage

A 6-year-old child presents to the clinic after an infection of the tubal tonsils spread to his middle ear. The bacteria from the tubal tonsils need to pass through which of the following structures to infect his middle ear cavity?

Torus tubarius

Cycloplegia is a condition in which the ciliary muscle is paralyzed, resulting in a loss of visual accommodation. Identify the condition in which a patient with cycloplegia would have the most difficulty seeing clearly.

Viewing close objects

You are performing a neurologic examination on a 43-year-old patient that recently had a cranial mass resected near the internal opening of the right jugular foramen. Based on the location of the surgery near the jugular foramen, you plan to test the function of cranial nerve XI (CN XI). Identify the physical exam finding that would most likely be observed if there was damage to this nerve.

Weakness when superiorly shrugging the right shoulder against resistance

DiGeorge syndrome is a genetic disorder that involves a deletion in chromosome 22 resulting in several midline defects. One common malformation associated with this syndrome is thymic aplasia, a congenital deficiency in the thymus. Which of the following mediastinal compartments is the thymus located within?

anterior