A patient has presented with an abnormal reflex response. In response to a flash of light, the patient will move his eyes towards the light but not turn his head. Which of the following may explain the condition?
A) The patient has damage to the accessory nerve (XI), affecting his ability to reflexively turn his head.
B) The patient has damage to the oculomotor nerve (III), affecting his ability to coordinate eye movement and head movement.
C) The patient has damage to his trochlear nerve (IV), accentuating his ability to move his eyes and rendering the need to move the head unnecessary.
D) The patient has damage to the occipital lobe of the cerebrum, causing him to be blind to the flash of light.

Question

Quizplus · Accepted Answer

The accessory nerve (XI) is responsible for innervating the sternocleidomastoid and trapezius muscles, which are involved in turning the head. Damage to this nerve would impair the ability to reflexively turn the head towards a stimulus, such as a flash of light, while not necessarily affecting the ability to move the eyes towards the light.

A Patient Has Presented with an Abnormal Reflex Response