The adult brain is often sectioned (cut) and viewed from different directions and angles. Each point of view provides an altered perspective of the brain that changes the appearance of the major divisions, landmarks, and structures.
The brain stem was represented on multiple angles, to show the external structures of the midbrain, pons and medulla oblongata (bulb) and a projection of the cranial nerve nuclei on the floor of the fourth ventricle.
Before we have a look at the brain diagram, it is important to go through a few facts about the brain and its function. This will help you understand the anatomy of the brain better. The average dimension of the adult human brain is 5.5 inches in width and 6.5 inches in length.