Which nerve provides preganglionic parasympathetic fibers destined for lacrimal gland that travel with the zygomatic nerve?

• A. Greater petrosal nerve
• B. Deep petrosal nerve
• C. Chorda tympani
• D. Nerve to stapedius

Answer: (A)

Parasympathetic supply to the lacrimal gland comes from the facial nerve. The preganglionic fibers originate in the superior salivatory nucleus and travel with the greater petrosal nerve to the pterygopalatine ganglion, where they synapse. From there, the postganglionic fibers hitchhike with the zygomatic nerve (a branch of V2) to reach the lacrimal gland via the lacrimal nerve (a branch of V1). Because these preganglionic parasympathetic fibers destined for the lacrimal gland travel on the greater petrosal nerve on their way to the pterygopalatine ganglion, that nerve is the correct answer. The deep petrosal nerve carries sympathetic fibers (not parasympathetic), the chorda tympani carries parasympathetic fibers to submandibular and lingual glands, and the nerve to stapedius is a motor branch.