Fracture of middle cranial fossa with absence of tears

In the fracture of middle cranial fossa, absence of tears would be due to lesion in:

A. Trigeminal ganglion
B. Greater petrosal nerve
C. Ciliary ganglion
D. Cervical ganglion

Answer is B. Greater petrosal nerve.

The greater petrosal nerve is a nerve in the skull that branches from the facial nerve; it forms part of a chain of nerves that innervates the lacrimal gland. The fibres have synapses in the pterygopalatine ganglion.

The greater petrosal nerve is a branch of the facial nerve that arises from the geniculate ganglion, a part of the facial nerve inside the facial canal. It enters the middle cranial fossa through the hiatus for the greater petrosal nerve (on the anterior surface of the petrous temporal bone). It proceeds towards the foramen lacerum, where it joins the deep petrosal nerve (sympathetic) to form the nerve of the pterygoid canal. The nerve of the pterygoid canal passes through the pterygoid canal to reach the pterygopalatine ganglion.

Damage to this nerve in the middle cranial fossa can result in absence of tears.