The strongly swollen transverse middle part of the brainstem, which descends into the medulla oblongata and upwards into the midbrain (mesencephalon).
The bridge is connected to the cerebellum by the very powerful middle cerebellar arms.
The bridge contains several cranial nerve nuclei and a myriad of so-called pons nuclei.
The latter receive signals from the cerebrum, rewire them and send them in to the opposite side of the cerebellar through the middle cerebellar arm.