The brain stem includes the medulla/ medulla oblongata, pons/ pons and midbrain /mesencephalon. The brainstem receives sensory information and conveys motor function from cranial nerves. It also serves as a conduit for information from ascending sensory and descending motor tracts. Portions of the medulla participate in essential blood pressure and respiratory functions The pons participate in the regulation of eye movements. Pons gets blood supply from the basilar artery/ a.basilaris. The anterior spinal artery/ a.spinalis anterior derived from the vertebral artery/ a.vertebralis provides blood supply of medulla.