1. The brain and spinal cord, constituting the cerebrospinal axis. 2. The afterbrain or medullary brain, the posterior division of the rhombencephalon from which are developed the medulla oblongata and the bulbar portion of the fourth ventricle.
The posterior part of the hind-brain; the medulla oblongata; brain and spinal cord generally.
After-brain; after part of posterior cerebral vesicle of embryo.
The cerebrospinal axis. [Gr.]