Cranial nerve IV

Cranial Nerve IV

Cranial Nerve IV, also known as the Trochlear Nerve

The Cranial Nerve IV, also known as the Trochlear Nerve, is one of the twelve Cranial nerves that are part of the Peripheral nervous system. It is the smallest nerve in terms of the number of axons it contains, and the longest in terms of its intracranial course.

Function

The primary function of the Cranial Nerve IV is to innervate the Superior oblique muscle, which is one of the Extraocular muscles that control the movements of the eye.

Anatomy

The Trochlear Nerve originates in the midbrain, specifically in the dorsal aspect of the Midbrain. It is unique among the cranial nerves in that it exits the brainstem dorsally.

Clinical significance

Damage to the Trochlear Nerve can result in Trochlear nerve palsy, which can cause vertical diplopia, where the patient sees two images vertically displaced.

See also

• Cranial nerves
• Superior oblique muscle
• Trochlear nerve palsy