What is a medula oblongata?
The medulla oblongata is the lower portion of the brainstem. By anatomical terms of location, it is rostral to the spinal cord and caudal to the pons, which is in turn ventral to the cerebellum. For a human or other bipedal species, this means it is above the spinal cord, below the pons, and anterior to the cerebellum. It controls autonomic functions and relays nerve signals between the brain and spinal cord. The medulla is often thought of as being in two parts, an open part (close to the pons), and a closed part (further down towards the spinal cord). The ‘opening’ referred to is on the dorsal side of the medulla, and forms part of the fourth ventricle of the brain. Running down the ventral aspect of the medulla are the pyramids which contain corticospinal fibres. On the open medulla, there is a slight bulge just behind the pyramids called the olive or olivary nuclei. Cranial nerve XII (the hypoglossal nerve) emerges between these two structures. Cranial nerves IX and X (glossopharyn
