1.
What embryological arch derivative is the Posterior belly of the Digastric muscle derived from?
Correct Answer
B. II
Explanation
that’s why it’s innervated by CN VII
2.
A younger man of 27 years comes to the clinic complaining of loss of movement of facial muscles on the left side of his face. After a quick physical exam you determine that the patient has a compression to a nerve where it is exiting the stylomastoid foramen, causing an appearance of sagging features on the left face. After your epidemiology class, you remember that because the patient is younger, this is will most likely be a transient event that should clear up in a few weeks. However you caution the patient that-
Correct Answer
D. His left eye will become dry and irritated due to the loss of function of orbicularis oculi and that it could help if he taped his eyelid shut while sleeping
Explanation
D - is correct because it’s innervated by facial nerve. A is incorrect because Greater Petrosal Nerve is proximal to the compression. C is CN XI. E is CN V.3
3.
A strong, healthy, attractive man walks into a female doctor's office. He describes a pain he has been feeling the last few days in his right neck. The doctor puts him in the chair and begins to study all the muscles of the neck taking note of the strength and firmness. His strap muscles are weak on the right side, but that he has no deficits in mouth or tongue muscles. No lymph nodes are swollen on palpation and there is no visible goiter. She tells him it is probably just a pinched nerve and that he works out too much.
The most likely nerve that she is describing is the –
Correct Answer
B. Nerve that loops around the internal jugular vein
Explanation
Nerve being described is Ansa Cervicalis which innervates most infrahyoid muscles.
4.
A tumor suppressing the Trochlear nerve would result in the impairment of what eye movement?
Correct Answer
C. Out and down
Explanation
Out and down (the Trochlear nerve (CN IV) innervates the Superior Oblique muscle which abducts and depresses the eye.)
5.
While running a red light at a busy intersection, Mr. Batman was involved in a car vs. car Motor Vehicle Accident (MVA). The other vehicle involved hit the driverside flank of the batmobile. Gotham City EMS arrived on scene to find a somewhat intoxicated Mr. Batman with no injuries. However, the passenger (Robin) was found unconscious in the passenger's seat with his face on the dash. Robin regained consciousness while being extracted from the batmobile. A head CT was performed on Robin 3 hrs. post-MVA and was found to be unremarkable. Approximately 72 hrs. later Robin lost consciousness again. Below is the image from Robin's 2nd head CT:
What type of hematoma does the CT display and can the hematoma cross to the opposite brain hemisphere?
Correct Answer
E. Subdural; No
Explanation
The image is of the typical crescent or concave spreading pattern seen in head CT's of subdural hematomas. Subdural hematomas can not cross to the opposite brain hemisphere due to the dividing barrier called the falx cerebri. The clinical presentation includes a biphasic episodic loss of consciousness (LOC). The reason for this is that the initial traumatic event causes the first LOC, and the second LOC is due to brain compression and displacement. The second LOC can occur up to 72 hrs. later because the torn bridging veins involved in this hematoma bleed at a slow but continuous rate, as appose to an arterial bleed which is fast and spurting in nature.
6.
A 30-year old male postal worker presents with double vision. Upon examination, you observe that his right eye does not follow your finger horizontally to the right visual field. Damage to which structure is the likely reason for this defect?
Correct Answer
D. Right sided CN VI palsy
Explanation
right eye can’t abduct=lateral rectus paralyzed which is innervated by CN VI (Abducens Nerve).
7.
A 45-year-old woman is suffering from numbness over the tip of her nose. Which of the following nerves is most likely to be damaged?
Correct Answer
A. OpHthalmic division of the trigeminal nerve
Explanation
Trigeminal Nerve’s ophthalmic division’s dermatome includes the eye and anterior portion of the nose.
8.
If a person is looking inward towards their nose and is unable to look down, which muscle may be injured?
Correct Answer
B. Superior oblique
Explanation
adducted depression isolates the action of the superior oblique.
9.
Which extra-ocular muscle(s) do(es) NOT originate from the Annulus tendineus?
Correct Answer
F. A&D
Explanation
Oblique muscles’ origin is on the wall of the orbit.
10.
The innervation of the Carotid body & the Carotid Sinus is?
Correct Answer
E. Mixed IX & X
Explanation
The carotid sinus is innervated by CN IX. The carotid body is innervated by branches from both CN IX and CN X. Think Body = Both
11.
The inferior thyroid vein drains into which of the following veins?
Correct Answer
C. BrachiocepHalic Vein
Explanation
The superior and middle thyroid veins drain into the internal jugular vein, and the inferior thyroid veins empty into the right and left brachiocephalic veins, respectively.
12.
Nerve to Mylohyoid innervates Mylohyoid muscle and what other muscle?
Correct Answer
A. Anterior belly of Digastric
Explanation
CN V.3 innervates anterior belly of digastrics and mylohyoid via nerve to Mylohyoid.
13.
A 3 year-old male presents to the pediatrician with fever, dysphagia (trouble swallowing), stiff neck, odynophagia (pain on swallowing), and stridor (inspiratory wheeze). History reveals an upper respiratory infection which gradually worsened. Visual examination of the oropharynx was not performed for fear of occluding the airway, but tender cervical lymphadenopathy was discovered. A CBC, blood culture, and a contrast-enhanced CT scan were performed. The CBC revealed leukocytosis with PMN predominance. The CT image below confirms a retropharyngeal abcess (A&B), so the patient is started on empirical antibiotics and scheduled for surgical drainage.
What forms the lateral border of the retropharyngeal space in the cervical region?
Correct Answer
D. Carotid Sheath
Explanation
Carotid sheath is formed by all 3 layers of deep cervical fascia and serves as the lateral border of the retropharyngeal space in the cervical region. This clinical vignette was based on “Retropharyngeal infections in children” in UptoDate.
14.
When testing the sensory innervation of the face, it is important to remember that the skin of the tip of the nose is supplied by the:
Correct Answer
C. OpHthalmic division of the trigeminal nerve
Explanation
The Ophthalmic division of the Trigeminal Nerve provides sensory innervation for the forehead, stopping at the level of the eyes and goes down the middle of the nose to the tip. It provides sensory to the upper eyelid. V2 is responsible for providing sensory to the lateral aspect of the nose.
15.
Which of the following muscles is NOT innervated by the facial nerve?
Correct Answer
B. Masseter
Explanation
Masseter is a muscle of mastication so it’s innervated by V.3
16.
During an anterior neck operation, a surgeon accidentally severed the ansa cervicalis. Which of the following muscles did NOT lose its innervation?
Correct Answer
C. Cricothyroid
Explanation
innervated by external branch of superior laryngeal nerve of CN X.
17.
During a battle for Ned dominance against Other-Ned, I lose because I’m not a fighter. Also, have you seen him? I don’t stand a chance. In the process I suffer a blow out fracture to my orbit with subsequent loss of CN IV. In what direction will my pupil present?
Correct Answer
D. Up and in
Explanation
Trochlear Nerve innervates superior oblique which normally depresses and abducts the eye. If this is lost, primary position will be up and slightly in (hyper-esotropia), so patients prefer to tilt their head down and away from the side of the palsied muscle to avoid diplopia (double vision).
18.
A patient presents to the clinic with constricted pupils and no sweating on the same side of the face. You suspect they have Horner's syndrome. You would also expect to see which of the following on the same side of the face?
Correct Answer
C. Fine ptosis, due to a functional loss of the Superior Tarsal muscle
Explanation
Horner's is a loss of Sympathetic innervation to the head. The 2 eye muscles innervated by the SNS are the dilator pupilae muscle and the superior tarsal muscle. The functions of both of these muscles are lost in Horner's so the pupil is constricted and the eyelid droops but only slightly. You would only see dense, or complete, ptosis if Levator Palpebrae (innervated by CN3) is damaged.
19.
Mr. Palmer is a 45 year old male complaining of soreness in his tongue. On inspection you find that he has an infection at the tip of his tongue. You think back to your anatomy days and remember the location of the lymph nodes that drain this area. And the answer is
Correct Answer
D. Submental triangle
Explanation
The submental lymph nodes are found in the submental triangle and they are responsible for draining the tip of the tongue and the lower lip.