The term hindbrain refers to one ot three components of the brain as defined by surgical dissection. The other components are the forebrain and the midbrain.The posterior-most of the three, its rostral boundary is with the midbrain: a nominally coronal plane located at the caudal margin of the inferior colliculus dorsally and the rostral margin of the basal pons ventrally. The caudal boundary is with the spinal cord and is defined by a nominally horizontal plane at the level of the foramen magnum. The hindbrain is composed of two parts: the metabrain and the medulla. Substructures of the hindbrain are derived for the most part, but not entirely, from the embryonic Rhombencephalon. Before the twentieth century, 'hindbrain' was a synonym of metabrain ( Swanson-2015 ).