Groove for lesser petrosal nerve

The groove for lesser petrosal nerve is situated laterally and below both the impression for the trigeminal ganglion and the groove for the greater petrosal nerve. It extends from this point in a posterolateral direction along the front surface of the petrous part of the temporal bone and concludes at the hiatus for the lesser petrosal nerve.

The lesser petrosal nerve itself, originating from the tympanic plexus within the middle ear cavity of the petrous bone, emerges at its hiatus. This point is located just below the hiatus for the greater petrosal nerve. The nerve then follows a path inwards, toward the foramen ovale, while staying beneath and outside the path of the greater petrosal nerve throughout its course. Eventually, the lesser petrosal nerve plunges into the foramen ovale, making its way into the infratemporal fossa area. Understanding the anatomical route and location of the lesser petrosal nerve is crucial since it transports the parasympathetic fibers that are responsible for stimulating the parotid gland.