telencephalon, diencephalon, brainstem and spinal cord

FIGURE 2-1

     Module 1 covers the anatomy of the Forebrain. Thus, as shown here, this module focuses on zone above the red line, which includes the Diencephalon and the Telencephalon (= cerebral hemisphere).
     Module 2 covers the anatomy of the Brainstem and Spinal Cord.
     
While this seems like a very tidy division, the situation is, in fact, more complex. The Diencephalon does indeed have a close developmental and functional relationship with the telencephalon. But it is also the "gateway" to the hemisphere, in that almost all ascending sensory pathways pass through the Diencephalon to reach the cerebral cortex. So it is inevitable that we will often think of it as being the rostral end of the brainstem, and most of the discussion of it will be found in Module 2. The thalamus is by far the largest subdivision of the Diencephalon and we may at times (incorrectly) use the two terms interchangeably.