The structure indicated by the arrow
A) is where the rubrospinal tract begins.
B) is where the corticospinal tract decussates.
C) is where the spinothalamic tract crosses.
D) is where third-order neurons of the posterior (dorsal) column tract originate.

Question

The structure indicated by the arrow 
A) is where the rubrospinal tract begins. 
B) is where the corticospinal tract decussates. 
C) is where the spinothalamic tract crosses. 
D) is where third-order neurons of the posterior (dorsal) column tract originate.

Quizplus · Accepted Answer

The arrow is pointing to the medullary pyramid, which is where the corticospinal tract decussates (crosses over) from one side of the brain to the opposite side of the body.

The Structure Indicated by the Arrow