system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
In a case of fracture of middle cranial fossa, lesion of which of the following structure result in absence of tears?
assistant
The correct answer is  Greater petrosal nerve is a branch of facial nerve. It traverse through the petrous pa of temporal bone, middle cranial fossa, pterygoid canal and pterygopalatine fossa to ultimately supply secretory function to the lacrimal gland. So in case of fracture of middle cranial fossa, this nerve is damaged which in turn lead to absent innervation of lacrimal glands and absent tears.