MODULE 5
THE CORTICO-RUBRO-SPINAL PATHWAY
The brainstem relay nucleus for this pathway is the red nucleus and it is obvious on the slides. Other parts of the pathway are as difficult to see, but you should be aware of its approximate position at both brainstem and spinal levels. Phylogenetically, this pathway is somewhat newer than the cortico-reticulo-spinal one, appearing at about the time when vertebrates acquired the ability to move their extremities with some skill. Thus, it is not surprising that it seems to be concerned with initiating movement in the distal parts of the arm and leg. The input to the red nucleus is uncrossed and apparently gets there by passing dorsal to the cerebral peduncle . The rubrospinal tract decussates, near its origin, in what is known as the ventral tegmental decussation. The pathway is shown schematically in the next view Figure 5-3 and in Blumenfeld's Figure 6.11B. Call up the views using Figure 5-14.
MODULE 5 HOME_____NEXT_____PIX BRAIN HOME