CN IV Course


The trochlear nerve exits the dorsal brainstem at the caudal midbrain. It crosses upon exiting the brainstem, curves around and passes through the posterior cerebral and superior cerebellar arteries. It then enters the cavernous sinus and exits through the superior orbital fissure where it innervates the superior oblique. Trochlear nuclei are located in the caudal midbrain at the level of the inferior colliculus.        

  1. Gross Cross Section
  2. Cartoon