Which cranial nerve innervates the lateral rectus muscle?

Which cranial nerve innervates the lateral rectus muscle?

• A. Abducens (CN VI)
• B. Oculomotor (CN III)
• C. Trochlear (CN IV)
• D. Optic (CN II)

Answer: (A)

The lateral rectus is the muscle that pulls the eye outward, enabling abduction. It is innervated by the abducens nerve (cranial nerve VI). This nerve travels from its nucleus in the pons to the orbit through the superior orbital fissure to reach the lateral rectus. When this nerve is impaired, abduction is lost and horizontal diplopia results. The oculomotor nerve (cranial nerve III) controls most of the other extraocular movements and pupil constriction, the trochlear nerve (cranial nerve IV) innervates the superior oblique, and the optic nerve (cranial nerve II) is purely sensory for vision. Therefore, the nerve that innervates the lateral rectus is the abducens nerve.

The lateral rectus is the muscle that pulls the eye outward, enabling abduction. It is innervated by the abducens nerve (cranial nerve VI). This nerve travels from its nucleus in the pons to the orbit through the superior orbital fissure to reach the lateral rectus. When this nerve is impaired, abduction is lost and horizontal diplopia results. The oculomotor nerve (cranial nerve III) controls most of the other extraocular movements and pupil constriction, the trochlear nerve (cranial nerve IV) innervates the superior oblique, and the optic nerve (cranial nerve II) is purely sensory for vision. Therefore, the nerve that innervates the lateral rectus is the abducens nerve.