Question

Name the parasympathetic nerves that innervate the eye. Mention the function of each and specify the neurotransmitter liberated by these nerves at the synapse.

Answer 1

The Edinger–Westphal nucleus is the parasympathetic pre-ganglionic nucleus that innervates the iris sphincter muscle and the ciliary muscle. It is also known as accessory oculomotor nucleus. The oculomotor nerve is the third of 12 pairs of cranial nerves in the brain. This nerve is responsible for eyeball and eyelid movement. The oculomotor nerve innervates extraocular muscles which include: the medial, inferior, and superior recti, the inferior oblique, and levator palpebrae muscles. The facial nerve innervation of eye here involves consensual blinking of both eyes in response to stimulation of one eye. Facial nerve stimulates the tear gland to secrete tear. Both the nerves, oculomotor nerve and facial nerve release acetylcholine as neurotransmitter in the synapse.