Hiatus for petrosal nerve

The hiatus for petrosal nerve is a small opening in the temporal bone of the skull. It serves as a passageway for the greater petrosal nerve, which is a branch of the facial nerve (cranial nerve VII). This nerve carries parasympathetic fibers to the lacrimal gland and the mucous membranes of the nasal cavity and palate.

Anatomy

The hiatus for petrosal nerve is located on the anterior surface of the petrous part of the temporal bone. It is situated near the trigeminal impression, which is the location where the trigeminal ganglion resides. The hiatus is an important landmark in the middle cranial fossa.

Function

The primary function of the hiatus for petrosal nerve is to allow the passage of the greater petrosal nerve. This nerve is responsible for carrying preganglionic parasympathetic fibers from the facial nerve to the pterygopalatine ganglion. From there, postganglionic fibers innervate the lacrimal gland, promoting tear production, and the mucous membranes of the nasal cavity and palate, aiding in secretion.

Clinical significance

Damage or lesions affecting the greater petrosal nerve as it passes through the hiatus can lead to a loss of lacrimation (tear production) and reduced secretion in the nasal cavity and palate. This can occur due to temporal bone fractures, surgical procedures, or tumors in the region.

See also

• Facial nerve
• Temporal bone
• Middle cranial fossa
• Pterygopalatine ganglion

References

• Template:Gray's Anatomy

External links

• Hiatus for petrosal nerve on WikiMD