Retro-olivary groove

The retroolivary groove is a distinct depression or groove located on the medulla, just posterolateral (behind and to the side) to the olive. This groove delineates the lateral extent of the olive and separates it from the more laterally positioned inferior cerebellar peduncle, located further lateral and behind the olive.

The retroolivary groove is also significant as it marks the sites of origin for several important cranial nerves, including the glossopharyngeal (9th), vagus (10th), and the cranial root of the accessory (11th) nerves.