Question

*A professor unexpectedly dropped a heavy textbook in his anatomy class and all of his students looked up, startled. These reflexive movements of their neck and eye muscles were mediated by the:

a. inferior olivary nuclei
b. superior colliculi
c. inferior colliculi
d. cerebral cortex

Answer 1

The startled response involved in students looking up due to a loud noise is mediated by the superior colliculus, a midbrain structure that integrates auditory and other sensory input to initiate muscle movement.

Step-by-step explanation:

The reflexive movements of the neck and eye muscles caused by students reacting to a loud noise, such as a textbook dropping, are mediated by the superior colliculus. This structure in the midbrain is key in integrating auditory, visual, and somatosensory input to help coordinate the movement of the head and eyes towards the source of the stimulus. In this case, when the textbook dropped, the stimulation of the muscles that caused students to look up was triggered by the superior colliculus receiving auditory input and initiating a coordinated response.