What are the parts of the brain stem and what do they do?
The brain stem, consisting of the midbrain (or mesencephalon), pons, and medulla oblongata, is the most primitive part of the brain, and is involved in many basic body functions. The midbrain relays motor signals from the cerebral cortex to the pons, and sensory transmissions in the opposite direction, from the spinal cord to the thalamus. The oculomotor (cranial nerve III) and the trochlear (IV) nerve arise in he midbrain The pons lies below the midbrain, and is involved with motor activity of the body and organs. Lying below the pons is the medulla oblongata. It is the upward continuation of the spinal cord, and contains pathways taking information between the brain and spinal cord. The hypoglossal (XII), spinal accessory (XI), glossopharygeal (IX), and vagus (X) nerves arise in the medulla oblongata, which also contains a central core of gray matter called the reticular formation.
