Question

1. right cn ix and x damage

a. no uvula elevation on either
side when right pharyngeal
wall is touched
b. with uvula elevation towards
the right side when touched
on the left pharyngeal wall
c. both
d. none

1. the 2 cranial nerves that

supply sensory fiber to the
olfactory epithelium are ____
(special sensory) and ____
(somatosensory)
a. i and v
b. i and vii
c. v and i
d. i and x

1. this will be your finding if

patient with afferent pupillary
defect on the affected eye is
tested with penlight on the
normal eye…
a. normal eye dilates
b. no reaction on contralate
eye
c. both dilates
d. none of the above

Explanation:

Question 77

Cranial nerves IX (Glossopharyngeal) and X (Vagus) are involved in pharyngeal reflex and uvula elevation. Damage to right CN IX and X means the right side's motor innervation for uvula elevation (via these nerves) is impaired. When the right pharyngeal wall is touched, the reflex (which relies on these nerves for motor response of uvula) won't work properly, so no uvula elevation on either side (since the right side can't elevate, and the left - right coordination via these nerves is disrupted here). Option b is incorrect because with right nerve damage, touching left pharyngeal wall should lead to uvula elevating towards left (not right). So the correct answer is a.

Question 78

• Cranial nerve I (Olfactory) supplies special sensory (olfactory) fibers to the olfactory epithelium.
• Cranial nerve VII (Facial) also has some sensory fibers (somatic sensory in the context of the question, though more accurately, it has taste and some general sensory from face but for the olfactory epithelium - related, VII has a role in the area's innervation for some sensory aspects). Cranial nerve V (Trigeminal) is more for general sensory of face, mouth etc., not olfactory epithelium. Cranial nerve X (Vagus) is for other regions. So the two cranial nerves are I (special sensory) and VII (somatic sensory - in the question's context), so option b is correct.

Question 79

In afferent pupillary defect (Marcus - Gunn pupil), the affected eye has a problem with the afferent (sensory) part of the pupillary light reflex. When light is shone on the normal eye, the normal eye's afferent pathway sends a signal to the brain. The brain then sends an efferent signal to both eyes (due to the consensual light reflex). So both the normal and the affected eye will dilate (since the efferent pathway is intact, and the brain's response to the normal eye's afferent input causes both pupils to react). Option a is wrong as both should react, option b is wrong as there is a reaction (dilation) on the contralateral (affected) eye. So option c is correct.

Answer:

a. No uvula elevation on either side when right pharyngeal wall is touched