Temporal bone, by the way, is the most complex bone in our body. It is embryologically formed by the fusion of 11 ossification centers* that incorporate the peripheral part of the audio-vestibular system and provide all necessary channels and openings for multiple cranial nerves & blood vessels passing through it.
*Navjot Singh. Prenatal growth of cranium, facial and oral structures. Chapter 3 from the Textbook of Orthodontics, ed. Gurkeerat Singh, third ed. JAYPEE, 2015, p21—27.
Os temporale dxt. ex situ & in situ.
Dorsomedial aspect of right temporal bone.
The list of terms:Pars squamosa (facies cerebralis) – Squamous part (cerebral surface) Pars petrosa (pyramis) – Petrous part (pyramid) of temporal bone Pars petrosa (processus mastoideus) – Petrous part (mastoid process) Incisura parietalis – Parietal notch Fissura petrosquamosa – Petrosquamous fissure
Lateral aspect of the right temporal bone.
The list of terms:Pars squamosa (facies temporalis) – Squamous part (temporal surface) Processus mastoideus (pars petrosa) – Mastoid process (petrous part) Pars tympanica – Tympanic part Incisura parietalis – Parietal notch Crista supramastoidea – Supramastoid crest Processus zygomaticus – Zygomatic process Fissura tympanomastoidea – Tympanomastoid fissure Fissura tympanosquamosa – Tympanosquamous fissure Fissura petrosquamosa – Petrosquamous fissure Fissura petrotympanica (Glasseri) – Petrotympanic fissure (glasserian fissure) Porus acusticus externus – Opening of external acoustic meatus Sulcus tympanicus – Tympanic groove Incisura tympanica – Tympanic notch Meatus acusticus externus – External acoustic (auditory) meatus
Medial aspect of the right temporal bone.
The list of terms:Margo sphenoidalis – Sphenoidal border Margo parietalis – Parietal border Incisura parietalis – Parietal notch Margo occipitalis – Occipital border Margo posterior partis petrosae – Posterior border of petrous part of the temporal bone Margo superior partis petrosae – Superior border of petrous part of the temporal bone Apex partis petrosae – Apex of petrous temporal bone Porus acusticus internus Meatus acusticus internus – Internal acoustic (auditory) meatus Apertura externa aqueductus vestibuli – External opening of vestibular aqueduct Sulcus sinus sigmoidei – Groove for sigmoid sinus Foramen mastoideum – Mastoid foramen Impressiones digitatae – Digitate impressions Juga cerebralia – Cerebral ridges of cranium
Anterior aspect of right temporal bone.
The list of terms:Fissura petrosquamosa – Petrosquamous fissure Canalis musculotubarius – Musculotubal canal Semicanalis m. tensoris tympani – Semicanal for tensor tympani muscle Semicanalis tubae auditoriae (auditivae) – Semicanal for the auditory tube Canalis caroticus – Carotid canal Hiatus n. petrosi minoris – Hiatus of canal for lesser petrosal nerve Hiatus n. petrosi majoris – Hiatus of canal for greater petrosal nerve
Top aspect of right temporal bone.
The list of terms:Fissura petrosquamosa – Petrosquamous fissure Tegmen tympani – Roog of tympanic cavity Eminentia arcuata – Arcuate eminence Impressio trigeminalis – Trigeminal impression Apex partis petrosae – Apex of petrous temporal bone Hiatus nervi petrosi minoris – Hiatus of canal for lesser petrosal nerve Sulcus n. petrosi minoris – Groove for lesser petrosal nerve Hiatus nervi petrosi majoris – Hiatus of canal for greater petrosal nerve Sulcus n. petrosi majoris – Groove for lesser petrosal nerve Sulcus sinus petrosi superioris – Groove for superior petrosal sinus
Posterior aspect of right temporal bone.
The list of terms:Porus acusticus internus Meatus acusticus internus – Internal acoustic (auditory) meauts Apertura externa aqueductus vestibuli – External opening of vestibular aqueduct Fossa subarcuata – Subarcuate fossa Sulcus sinus petrosi superioris – Groove for superior petrous sinus Sulcus sinus sigmoidei – Groove for sigmoid sinus Sulcus sinus petrosi inferioris – Groove for inferior petrous sinus Incisura jugularis – Jugular notch Processus intrajugularis – Intrajugular process Processus styloideus – Styloid process Vagina processus styloidei – Sheath of styloid process Incisura mastoidea – Mastoid notch Sulcus a. occipitalis – Groove for occipital artery Foramen mastoideum – Mastoid foramen
Canalis facialis within the semi-transparent right temporal bone.
The list of terms:Meatus acusticus internus – Internal acoustic (auditory) meatus Canalis facialis – Facial canal Foramen stylomastoideum – Stylomastoid foramen Genu canalis facialis – Genu of facial canal Hiatus nervi petrosi majoris – Hiatus of canal for greater petrosal nerve
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Internal acousttic meatus and the osseous labyrinth within the temporal bone.
The red structure you see in the image above is the osseous labyrinth – the channel system surrounded by a thick cortical bone layer within the petrous part of the temporal bone. This cortical bone is one of the densest structure in our skeleton (petrous in Latin means stone-like), so the vestibular and hearing apparatus arranged in these channels is particularly well protected.
The list of terms:Meatus acusticus internus – Internal acoustic (auditory) meatus Cochlea Vestibulum Canales semicirculares – Osseous semicircular canals
Cellulae mastoideae within the semi-transparent temporal bone. The lateral projection.
The complex view of some major internal structures of the temporal bone, including mastoid cells (yellow), the facial canal (green), labyrinth (red), tympanic cavity with canalis musculotubarius (magenta), and meatus acusticus internus (blue).
Temporal bones ex situ & in situ. 360° rotation.
First published: May/2019
Last update: 14/Nov/2020