Each of the fourth pair of cranial nerves, supplying the superior oblique muscle of the eyeball.
- ‘Each trochlear nerve makes its exit through the caudal tectum (the dorsal portion of the midbrain), immediately lateral to the frenulum of the superior medullary velum.’
- ‘This nerve may appear to be derived from the trochlear nerve.’
- ‘The trochlear nerve nuclei are located ventral to the mesencephalic aqueduct.’
- ‘The exceptions are the superior oblique, which is enervated by the trochlear nerve (Cranial nerve IV), and the lateral rectus, which is enervated by the abducens (Cranial Nerve VI).’
- ‘The tiny super orbital and super trochlear nerves above the brow are carefully protected.’