The brainstem consists of the entire caudal region of the brain beneath the cerebellum, behind the thalamus, and in front of the spinal cord. It is the huge stalk of the brain which contains all the sensory, motor and interconnecting cellular groups, together with all the fiber tracts which pass through this region. The fiber tracts that interconnect the forebrain (thalamus, basal forebrain, and cerebral cortex), spinal cord, and cerebellum.