Temporal bone

The temporal bone ( temporal bone ) is one of the bones of the cranium. It is located laterally in the posterior cranial area. The temporal bone contains the middle and inner ear and forms the glenoid fossa of the temporomandibular joint.

The temporal bone is divided into four parts:

  • Squamous ( scale part )
  • Tympanic ( tympanic part, surrounding the ear canal and the middle ear )
  • Mastoid ( mastoid )
  • Petrous ( rock part, temporal bone )

While the temporal squama ( squama ) with the adjacent skull bone with sutures ( sutures ) is connected, the remaining portions of the temporal bone between the temporal squama, occipital bone, sphenoid and parietal bones are wedged and connective tissue attached (so-called Gomphosis ). Therefore, these parts are also referred to as the petrous pyramid in animals, in humans, however, only the actual petrous.

Squamous

The developed squamous ( shed part or temporal squama ), phylogenetically from the shed leg ( squamosal ), is the largest section of the temporal bone and forms a part of the lateral wall of the cranial cavity.

In the front area is the zygomatic extension ( zygomatic process ossis temporalis ), which forms the processus temporalis of the zygomatic arch zygomatic bone ( zygomatic arch ). In the direction of occipital, the zygomatic arch ( Crista supramastoidea ) sets as a shallow bar continued over the entire temporal squama.

At the base of the articulation surface is Jochfortsatzes for (secondary) TMJ the mammal, which is referred to as glenoid fossa. Behind it rises the processus retroarticularis.

Tympanic

The tympanic ( tympanic part ) surrounds the outer ear canal ( external acoustic meatus ) and, together with the tympanic membrane, the lateral (side ) wall of the tympanic cavity ( cavum tympani ) and thus of the middle ear.

In some mammals (humans, horses, cattle ) forms part of the tympanic bony collar around the styloid process ( styloid process ) of the timpani part ( vagina processus styloidei ). Between the tympanic part and the petrous is a column that petrotympanic fissure. Through them, the chorda tympani pulls (timpani string ) of the facial nerve to the outside.

Mastoid

The mastoid ( mastoid ) carries the mastoid process ( mastoid process ). He is the approach taken by some long neck muscles ( sternocleidomastoid muscle ). The mastoid is hollow in most mammals. The cave inside the mastoid process ( mastoid antrum ) is like the middle ear lined by a mucous membrane and communicates with the tympanic cavity through an opening ( aditus ad antrum ) in conjunction. With the antrum to communicate in a highly variable extent more cavities mastoid cells ( mastoid air cells ). Antrum and Cellulae include air, which communicates with the nasopharynx in connection via the middle ear and the Eustachian tube.

Petrous

See petrous

Petrous part of the temporal bone Phylogenetics Eagle syndrome
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