Human Brain (Superior View)

brain object supplied by Viewpoint.

Brain Stem

The Human Brain is divided into two cerebral hemispheres called the cerebrum. The surface of each hemisphere is thrown into folds, or gyri. Each hemisphere can be divided into four lobes. There areas are frontal, occipital, temporal, and parietal.

The brain stem is called the Medulla Oblongata which basically connects the spinal cord to the rest of the nerve tracts in the brain. The dorsal surface of the Medulla forms the florr of the fourth ventricle. On the ventricle surface, two longitudinal ridges are seen. These are the pyramids, which contain motor fibers from the precentral gyrus. In addition to connecting nerve tracts, the Medulla contains groups of neutrons which are responsible for circulation and respiration functions.

Brain Stem image