Petrous part of the temporal bone

The petrous bone or the petrous pyramid ( petrous [ ossis temporalis ], petrosal, outdated and Pyramis ) is the hardest bone of the mammalian and human skull and a portion of the temporal bone ( temporal bone ). It surrounds the inner ear (labyrinth ).

Sometimes, especially in animal anatomical region, tympanic be ( surrounding the middle ear ) and mastoid portion of the temporal bone is also counted in the petrous pyramid.

Due to the petrous pyramid into account inter alia the facial nerve and the tympanic nerve. At the front face ( inner face of animals ) is a shallow pit of the trigeminal ganglion.

Anatomy

The temporal bone has three important additions:

• Internal acoustic meatus ( opening inner ear ): Admission of the facial nerve and vestibulocochlear nerve
• Stylomastoid foramen: exit of the facial nerve
• Canalis musculotubarius: Channel of the Eustachian tube ( auditory tube ) into the middle ear

A column ( petrotympanic fissure ) between petrous and tympanic part ( tympanic ) of the temporal bone is the exit of the tympanic string ( chorda tympani ).

In some mammals ( eg, human, horse, cattle ) is attached ligamentous the hyoid bone at the styloid process ( styloid process ) of the temporal bone.