Semester 2 /Neuro, Week 2 - Orbit, Face, Skull
Questions and Answers
- 1.
A 50-year old man present with complaint of double vision. While testing the patient's right eye movement during a cranial nerve test, the physician noted that the patient cannot elevate the adducted eye. Which of the following muscles is involved?
- A.
Superior rectus
- B.
Inferior rectus
- C.
Lateral rectus
- D.
Superior oblique
- E.
Inferior oblique
Correct Answer
E. Inferior obliqueExplanation
The correct answer is Inferior oblique. The patient's inability to elevate the adducted eye suggests a weakness or paralysis of the inferior oblique muscle. The inferior oblique muscle is responsible for elevating the eye when it is adducted or turned inward. Dysfunction of this muscle can result in double vision and difficulty with eye movements.Rate this question:
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- 2.
A patient is found to be unable to dilate his pupil and has drooping left eyelid ptosis). Ptosis disappears when he looks up. What structure is damaged?
- A.
Vagus nerve
- B.
Oculomotor nerve
- C.
Superior cervical ganglion
- D.
Optic nerve
- E.
Superior rectus muscle
Correct Answer
C. Superior cervical ganglionExplanation
The superior cervical ganglion is responsible for innervating the dilator muscle of the pupil and the smooth muscle of the upper eyelid. Damage to the superior cervical ganglion would result in the inability to dilate the pupil and the presence of ptosis. The fact that the ptosis disappears when the patient looks up suggests that the damage is not in the oculomotor nerve, which controls the levator palpebrae superioris muscle responsible for lifting the eyelid. Therefore, the most likely structure that is damaged in this case is the superior cervical ganglion.Rate this question:
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- 3.
In a blow-out fracture of the orbit, the floor of the orbit is fractured. Which of the following movements of the eyeball is lost?
- A.
Lateral
- B.
Upward
- C.
Medial
- D.
Downward
- E.
Downward and lateral
Correct Answer
B. UpwardExplanation
In a blow-out fracture of the orbit, the floor of the orbit is fractured. This can lead to entrapment of the inferior rectus muscle, which is responsible for upward movement of the eyeball. Therefore, in this condition, the movement of the eyeball that is lost is upward.Rate this question:
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- 4.
A 16-year-old teenager presents with complaint of double vision. The chief resident asked you to assess the functions of the extrinsic eye muscles. While testing the patient's left eye movement, you noted that the patient cannot depress the adducted eye. Which of the following muscles is involved?
- A.
Superior rectus
- B.
Superior oblique
- C.
Inferior rectus
- D.
Lateral rectus
- E.
Inferior oblique
Correct Answer
B. Superior obliqueExplanation
The superior oblique muscle is involved in the patient's inability to depress the adducted eye. The superior oblique muscle is responsible for depressing and abducting the eye. When this muscle is not functioning properly, it can result in double vision and difficulty moving the eye in certain directions.Rate this question:
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- 5.
A 20-year old man presents with double vision after a car accident. The ER resident tests the eye muscle functions and finds that the patient is unable to elevate the adducted right eye. Which muscle is not functioning properly?
- A.
Inferior rectus
- B.
Superior oblique
- C.
Superior rectus
- D.
Lateral rectus
- E.
Inferior oblique
Correct Answer
E. Inferior obliqueExplanation
The patient is unable to elevate the adducted right eye, which suggests dysfunction of the muscle responsible for this movement. The muscle that elevates the adducted eye is the inferior oblique muscle. Therefore, if the patient is unable to elevate the adducted right eye, it indicates that the inferior oblique muscle is not functioning properly.Rate this question:
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- 6.
Which of the following layers of the scalp constitute the "danger" layer?
- A.
Loose areolar tissue layer
- B.
Skin
- C.
Pericranium
- D.
Subcutaneous layer
- E.
Epicranial aponeurosis
Correct Answer
A. Loose areolar tissue layerExplanation
The "danger" layer of the scalp refers to the layer that is prone to potential complications during surgical procedures or injuries. The loose areolar tissue layer, also known as the subaponeurotic layer, is considered the "danger" layer because it contains numerous blood vessels and emissary veins that connect the scalp with the intracranial venous sinuses. Therefore, any damage or infection in this layer can lead to serious complications such as hematoma or infection spreading into the cranial cavity.Rate this question:
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- 7.
At Pterion, which of the following bones does not articulate?
- A.
Parietal
- B.
Frontal
- C.
Zygomatic
- D.
Temporal
- E.
Sphenoid
Correct Answer
C. ZygomaticExplanation
The zygomatic bone does not articulate at the pterion. The pterion is a point on the side of the skull where four bones meet: the parietal, frontal, temporal, and sphenoid bones. These bones articulate with each other at the pterion, but the zygomatic bone does not join this articulation.Rate this question:
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- 8.
An elderly patient developed fever and worsening headache a few days after sustaining a scalp laceration and subsequent infection due to a car accident. At the hospital the case was diagnosed as meningitis and superior sagittal sinus thrombosis. The attending physician suggested that infection to the sinus initially spread through one of the scalp layers. The scalp layer involved is:
- A.
Connective tissue (dense)
- B.
Areolar tissue
- C.
Epicranial aponeurosis
- D.
Periosteum
- E.
Skin
Correct Answer
B. Areolar tissueExplanation
The correct answer is Areolar tissue. Areolar tissue is a loose connective tissue that is found in the scalp. It contains a network of blood vessels and lymphatic vessels, which can provide a pathway for infection to spread. In this case, the infection from the scalp laceration likely spread to the superior sagittal sinus through the areolar tissue layer.Rate this question:
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- 9.
A 25-year-old woman sustains a head injury. A radiograph of the skull shows a fracture of the foramen ovale. Which of the following nerves would most likely be damaged by this event?
- A.
Ophthalmic nerve
- B.
Maxillary nerve
- C.
Optic nerve
- D.
Mandibular nerve
- E.
Trochlear nerve
Correct Answer
D. Mandibular nerveExplanation
A fracture of the foramen ovale would most likely damage the mandibular nerve. The mandibular nerve is one of the three divisions of the trigeminal nerve (cranial nerve V) and passes through the foramen ovale, which is located in the sphenoid bone. Damage to the mandibular nerve can result in sensory loss, muscle weakness, and difficulty with chewing and biting.Rate this question:
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