Postolivary

Postolivary is an anatomical term used to describe a location behind the olive in the medulla oblongata. The olive refers to the inferior olivary nucleus on the ventral surface of the medulla, and postolivary contrasts with preolivary, which lies anterior to the olive.

On the ventral medulla, two major sulci relate to the olives: the preolivary sulcus, between the pyramid and the olive, and the postolivary sulcus, between the olive and the adjacent inferior cerebellar peduncle. The rootlets of several cranial nerves emerge near these sulci; the hypoglossal nerve (CN XII) exits via the preolivary sulcus, while the glossopharyngeal (CN IX), vagus (CN X), and accessory (CN XI) nerves exit via the postolivary sulcus.

Thus, the term postolivary is primarily used to denote structures and regions in the brainstem behind the olive, particularly those associated with cranial nerves IX–XI and nearby autonomic and motor pathways. These pathways contribute to swallowing, palate and laryngeal function, and parasympathetic innervation.

Clinically, lesions in the postolivary region can affect critical functions such as swallowing and voice, gag reflex, and other IX–XI–related activities, depending on the exact location and extent of involvement. Etymologically, postolivary derives from post- meaning behind and olives, referring to the anatomical relationship to the inferior olivary nucleus.