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Temporal bone external surface right view. Human Temporal Bone Anatomy - Information

The paired bone is part of the base and lateral wall cerebral skull and is located between the sphenoid (front), parietal (above) and occipital (rear) bones. Temporal bone is a bone receptacle for the organs of hearing and balance; vessels and nerves pass through its channels. The temporal bone forms a joint with lower jaw and connects to the zygomatic bone, forming the zygomatic arch. In the temporal bone, a pyramid (stony part) with a mastoid process, a tympanic, and a squamous part are distinguished.

Pyramid, or the stony part is so called because of the hardness of its bone substance and has the shape of a trihedral pyramid. Inside it is the organ of hearing and balance. The pyramid in the skull lies almost in a horizontal plane, its base is turned back and laterally and passes into the mastoid process.

top of the pyramid free, directed forward and medially. There are three surfaces in the pyramid: anterior, posterior and inferior. The anterior and posterior surfaces face the cranial cavity, the lower surfaces outward and are clearly visible from the side of the outer base of the skull. These surfaces of the pyramid are separated by three edges: front, back and top.

Front surface of the pyramid facing forward and upward. Laterally, it passes into the cerebral surface of the squamous part, from which, in young people, the pyramid is separated by a stony-squamous gap. Next to this gap on the short front edge of the pyramid is the opening of the musculo-tubal canal. This canal is divided by an incomplete septum into two semi-canals: a semi-canal of the muscle that strains the eardrum, and a semi-canal auditory tube. The semicanal of the auditory tube on the whole skull is visible from the side of its outer base. In the middle part of the front surface of the pyramid, a small arched elevation is visible. It is formed by the anterior (upper) semicircular canal of the bone labyrinth lying in the thickness of the pyramid. inner ear. Between the arched elevation and the stony-scaly fissure, a flattened section of the anterior surface of the pyramid stands out - the roof of the tympanic cavity. Near the apex on the anterior surface of the pyramid is a trigeminal depression - a trace of the attachment of the trigeminal node of the same nerve. Lateral to the trigeminal depression there are two small openings: the cleft (opening) of the canal of the greater stony nerve, from which the furrow of the greater stony nerve originates. Somewhat anteriorly and laterally there is a cleft (hole) of the canal of the small stony nerve.

The top edge of the pyramid separates the anterior from the posterior. A furrow of the superior stony sinus runs along this edge.

The back surface of the pyramid facing back and medially. Approximately in the middle of the posterior surface of the pyramid there is an internal auditory opening passing into a short wide canal - the internal auditory canal, at the bottom of which there are several openings for the facial (VII pair) and vestibulocochlear (8 pair) cranial nerves, as well as for the artery and veins of the vestibule - cochlear organ. Lateral and above the internal auditory opening is the infraarc fossa. The process of the hard shell of the brain enters this fossa. Below and lateral to it there is a small gap - the outer aperture (hole) of the water supply of the vestibule.

Rear edge of the pyramid separates its back surface from the bottom. A furrow of the inferior stony sinus passes through it. At the lateral end of this groove, next to the jugular fossa, there is a dimple, at the bottom of which there is an external aperture (hole) of the cochlear tubule.

Bottom surface of the pyramid visible from the side of the outer base of the skull and has a complex relief. Closer to the base of the pyramid is a rather deep jugular fossa, on the front wall of which there is a groove ending in the mastoid opening of the tubule of the same name. The jugular fossa does not have a wall on the back side - it is limited by the jugular notch, which, together with the notch of the same name occipital bone forms a jugular foramen on the whole skull. Through it pass the internal jugular vein and three cranial nerves: glossopharyngeal (9th pair), vagus (10th pair) and accessory (11th pair). Anterior to the jugular fossa, the carotid canal begins - the external opening of the carotid canal is located here. The internal opening of the carotid canal opens at the top of the pyramid. In the wall of the carotid canal, near its external opening, there are two small dimples that continue into thin carotid canals that connect the carotid canal to the tympanic cavity.

On the comb separating the external opening of the carotid canal from the jugular fossa, a stony dimple is barely visible. At the bottom of it, the lower opening of the tympanic tubule opens. Lateral to the jugular fossa near the mastoid process, a thin and long styloid process protrudes. Behind it, between the styloid and mastoid processes, there is a stylomastoid foramen, with which the canal of the facial nerve ends in this place (7th pair).

Mastoid, located behind the external auditory canal and is back temporal bone. Above the squamous part of the temporal bone, the mastoid process is separated by the parietal notch. Its outer surface is convex, rough. Muscles are attached to it. At the bottom, the mastoid process is rounded (palpable through the skin), on the medial side it is limited by a deep mastoid notch. Medial to this notch is the sulcus of the occipital artery. At the base of the mastoid process, closer to the posterior edge of the temporal bone, there is an inconstant mastoid opening for the mastoid emissary vein. On the inner surface of the mastoid process facing the cranial cavity, a deep and rather wide groove of the sigmoid sinus is visible. Inside the process are mastoid cells separated from each other by bony septa. The largest of them, the mastoid cave, communicates with the tympanic cavity.

drum part is a small, curved in the form of a gutter, open top plate, connecting with other parts of the temporal bone. Merging with its edges with the scaly part and with the mastoid process, it limits the external auditory opening on three sides (front, bottom and back). The continuation of this opening is the external auditory meatus, which reaches the tympanic cavity. Forming the anterior, inferior, and posterior walls of the external auditory canal, the tympanic part fuses behind with the mastoid process. At the site of this fusion, behind the external auditory opening, a tympanic-mastoid fissure is formed.

In front of the auditory opening under the mandibular fossa there is a tympanic-squamous fissure, into which a narrow bone plate protrudes from the inside - the edge of the roof of the tympanic cavity. As a result, the tympanic-squamous fissure is divided into a stony-squamous fissure lying closer to the mandibular fossa and a stony-squamous fissure (glazer's fissure) located closer to the pyramid. Through this last gap, a branch of the facial nerve, the tympanic string, emerges from the tympanic cavity. The flat process of the tympanic part, facing downward, covers the base of the styloid process in front, forming the sheath of the styloid process.

scaly part is a convex outwards plate with a beveled free upper edge. It is superimposed like scales (scales) on the corresponding edge of the parietal bone and big wing sphenoid bone, and below it connects to the pyramid, mastoid process and tympanic part of the temporal bone. outer smooth temporal surface the vertical part of the scales is involved in the formation of the temporal fossa. On this surface, a furrow passes vertically in the days of the temporal artery.

From the scales, somewhat higher and anterior to the external auditory opening, the zygomatic process originates. It goes forward, where it connects with the temporal process of the zygomatic bone with its serrated end, forming the zygomatic arch. At the base of the zygomatic process is the mandibular fossa, for connection with the condylar (articular) process of the lower jaw. In front, the mandibular fossa is limited by the articular tubercle, which separates it from the infratemporal fossa.

On the cerebral surface, finger-like impressions and arterial grooves are visible - traces of the fit of the middle meningeal artery and its branches.

Canals of the temporal bone

sleepy channel through which the internal carotid artery passes into the cranial cavity, begins on the lower surface of the pyramid. Here, anterior to the jugular fossa, is the external opening of the carotid canal. Further, the carotid canal rises upward, bends at a right angle, goes forward and medially. The canal to the cranial cavity is opened by the internal opening of the carotid canal.

Musculo-tubal canal has a common wall with the carotid canal. It starts in the corner formed by the apex of the pyramid and the squamous part of the temporal bone, goes in the thickness of the bone posteriorly and laterally, parallel to the anterior surface of the pyramid. The musculoskeletal canal is divided by a longitudinal horizontal partition into two semi-canals. The upper semi-canal is occupied by the muscle that strains the tympanic membrane, and the lower one is the bone part of the auditory tube. Both semi-channels open into the tympanic cavity on its anterior wall.

front channel in which the facial nerve passes, begins at the bottom of the internal auditory canal, then in the thickness of the pyramid goes horizontally from back to front, perpendicular to its longitudinal axis. Having reached the level of the cleft of the canal of the large stony nerve, the facial canal leaves laterally and posteriorly at a right angle, forming a bend - the knee of the facial canal. Further, the channel follows horizontally along the axis of the pyramid in the direction of its base. Then it turns vertically down, bending around the tympanic cavity, and on the lower surface of the pyramid ends with a stylomastoid opening.

Drum string tubule starts from the canal of the facial nerve, slightly above the stylomastoid opening, goes forward and opens into the tympanic cavity. In this tubule passes a branch of the facial nerve - a tympanic string, which then exits the tympanic cavity through the stony-tympanic fissure.

drum tubule begins in the depths of the stony hole, goes up, pierces the lower wall of the tympanic cavity and continues on the labyrinth wall of this cavity on the surface of the cape in the form of a furrow. Then it perforates the septum of the musculo-tubal canal and ends with a cleft of the canal of the small stony nerve on the anterior surface of the pyramid. In the tympanic tubule passes the tympanic nerve - a branch of the 9th pair of cranial nerves.

mastoid tubule originates in the jugular fossa, crosses the facial canal in its lower part and opens into the tympanic-mastoid fissure. The auricular branch of the vagus nerve passes through this tubule.

Carotid tubules(two) begin on the wall of the carotid canal (near its outer opening) and penetrate into the tympanic cavity. Serve for passage into the tympanic cavity of the nerves of the same name.

It consists of many elements (channels, furrows, surfaces, tubercles, etc.) and students of medical academies remember how they studied it on Latin language like a bad dream.

The temporal bone is located on the border between the cranial vault and the base of the skull. It is connected to almost all other bones of the skull. different types connections. It contains the organs of balance (vestibular apparatus) and hearing ( inner ear). From below, various muscles of the neck are attached to it, from the inside, the carotid artery (internal branch) passes through it, and on the outside there is an auditory opening on its surface. These are far from all the formations that the temporal bone has.

Canals of the temporal bone

There are several canals and tubules in the temporal bone:

sleepy channel;
tubules sleepy-tympanic;
musculo-tubal canal;
front channel;
drum tubule;
drum string tubule;
mastoid canal.

Each canal of the temporal bone contains a certain anatomical formation. Consider the anatomy of these channels in more detail.

sleepy channel

This canal is named so because it contains the temporal part of the internal carotid artery. The carotid canal (in Latin canalis caroticus) originates from below the temporal bone with an external opening, passes through its thickness upwards and then turns anteriorly at almost a right angle and ends in the cranial cavity. The ICA (internal carotid artery) supplies most of the brain. The carotid artery in the canal is accompanied by veins and a plexus of nerve fibers of the sympathetic nervous system.

Carotid tubules

In Latin - canaliculi caroticotympanici - they are two small tubules that branch off from the carotid canal and lead into the tympanic cavity. Contain these channels carotid-tympanic nerve fibers.

Musculo-tubal canal

In Latin - canalis musculotubarius. It originates from the anterior superior wall of the tympanic cavity. The entrance to the canal is located near the external auditory opening. Inside the channel itself there is a horizontal partition that divides it into two half-channels. In the upper semi-canal lies a muscle that strains the eardrum. It is smaller than the bottom. The lower channel forms an anatomical connection between the pharyngeal cavity (atmospheric pressure) and the tympanic cavity to equalize air pressure on opposite sides of the tympanic membrane. Thanks to this channel, we can always hear the same at various fluctuations in atmospheric pressure. On the other hand, inflammation of the mucous membrane of this channel can lead to inflammatory processes in the tympanic cavity.

front channel

The facial canal (in Latin canalis facialis) originates in the lower part of the internal auditory meatus and runs horizontally. Inside the temporal bone, it turns at a right angle, forming the knee of the facial canal, and exits into the tympanic cavity. Having passed through the latter in the posterior direction, it turns down and goes to the surface of the temporal bone, where it ends with a hole, which is called the stylomastoid because of the proximity of the styloid and mastoid process near it.

Drum string tubule

In Latin - canaliculus chordae tympani. It originates from the facial canal near the stylomastoid foramen and ends in the tympanic cavity. The contents of this canal are the nerve that innervates the anterior two-thirds of the tongue (taste sensations) and the salivary glands (sublingual and submandibular). This nerve is called the drum string.

drum tubule

In Latin - canaliculus tympanicus. It originates on the surface of the temporal bone (its petrous part) and also leads to the tympanic cavity.

mastoid tubule

In Latin - canaliculus mastoideus. It contains the ear branch of the nervus vagus (vagus nerve). It starts in the jugular fossa and leads to the tympanic mastoid fissure.

As you can see, the temporal bone is literally pitted with various channels, tubules, furrows and other anatomical formations. Especially when you consider that its volume (stony part) is slightly larger than the volume of a matchbox. All this is due to the presence in the temporal bone of ultrafine organs of hearing and coordination, which have a rich innervation, as well as blood supply.

Video: Temporal bone - Channels

The carotid canal, canalis caroticus, begins in the middle sections of the lower surface of the stony part with an external opening. At first, the channel goes up, being located here in front of the cavity middle ear, then, bending, follows anteriorly and medially and opens at the top of the pyramid with an internal opening (pass through the carotid canal internal carotid artery accompanying her veins and plexus of sympathetic nerve fibers).

Carotid tubules, canaliculi caroticotympanici, two small tubules branching off from the carotid canal that lead to the tympanic cavity (the carotid tympanic nerves pass through them).

The facial canal, canalis facialis, begins at the bottom of the internal auditory canal, meatus acusticus internus (in the field of the facial nerve, area n. facialis; see vol. III, Organ of hearing). Going horizontally and almost at right angles to the axis of the stony part, the canal goes to its front surface to the cleft of the canal of the large stony nerve, hiatus canalis petrosi majoris. Here, turning at a right angle, it forms the knee of the facial canal, geniculum canalis facialis, and passes to the posterior part of the medial wall of the tympanic cavity (respectively, on this wall of the tympanic cavity there is a protrusion of the facial canal, prominentia canalis facialis). Further, the canal, heading backwards, follows along the axis of the rocky part to the pyramidal eminence, eminentia pyramidalis. from here it goes down, in a vertical direction, and opens with an awl-mastoid opening, foramen stylomastoideum (the facial and intermediate nerves, arteries and veins pass through the canal).

Drumstring Canadian, canaliculus chordae tympani. begins on the outer wall of the facial canal, a few millimeters above the awl-mastoid opening. Heading forward and upward, the Canadian enters the tympanic cavity, opening on its back wall (a branch of the intermediate nerve passes through the tubule - the drum string, chorda tympani, which, having entered the tympanic cavity through the Canadian, leaves it through the stony-tympanic shell).

Drum Canadian, canaliculus tympanicus, begins on the lower surface of the stony part, in the depths of the stony dimple, fossula petrosa. Then he goes to the lower wall of the tympanic cavity and, perforating it, enters the tympanic cavity. Here it passes along its medial wall and is located in the furrow of the cape, sulcus promontorii. Then it follows to the upper wall of the tympanic cavity, where it opens with a cleft canal of the small stony nerve, hiatus canalis n. petrosi minoris.

The musculoskeletal canal, canalis musculotubarius, is a continuation of the anterior upper part of the tympanic cavity. The external opening of the canal begins at the notch between the stony and squamous parts of the temporal bone, at the anterior end of the stony-squamous fissure and approaches the upper part of the anterior wall of the tympanic cavity. It lies laterally and slightly posterior to the horizontal part of the carotid canal and runs almost along the axis of the petrous part. Horizontally located septum of the muscular-tubal canal. septum canalis musculotubarii. divides the canal into the upper, smaller, semi-canal of the muscle that strains the eardrum, semicanalis musculi tensoris tympani, and the lower, larger, semi-canal of the auditory tube, semicanalis tuhae auditivae (in the first lies the muscle that strains the eardrum, the second connects the tympanic cavity with the cavity of the pharynx; see vol. III, Organ of hearing).

Mastoid Canadian, canaliculus mastoideus, begins in the depths of the jugular fossa, runs across the lower part of the facial canal and opens in the tympanic-mastoid fissure (the ear branch of the vagus nerve passes through the canaliculus).

The tympanic cavity, cawm tympani, is an elongated, laterally compressed cavity lined with a mucous membrane. Three auditory ossicles lie inside the cavity: the malleus, malleus, anvil, incus, and the stirrup, slopes, which, articulated with each other, form a chain of auditory ossicles (for further details about the structure of these canals, the tympanic cavity, the auditory ossicles and the labyrinth; see Vol. Sh, Organ of hearing). The tympanic part, pars tympanica, is the smallest part of the temporal bone. It has the shape of a slightly curved annular plate and forms the anterior, inferior, and part of the posterior wall of the external auditory canal. meatus acusticus externus. The outer edge of the tympanic part, closed on top by the scales of the temporal bone, limits the external auditory opening, porus acusticus externus. At the posterior upper outer edge of this opening there is an overpass spine, spina suprameatum. On the border of the larger, inner, and smaller, outer, parts of the external auditory canal, there is a tympanic sulcus, sulcus tympanicus (the place where the eardrum is attached). At the top, it ends with two protrusions: in front of the large tympanic spine, spina tympanica major, and behind - the small tympanic spine, spina tympanica minor. Between these protrusions is a tympanic notch, incisura tympanica, which opens into the epitympanic pocket, recessus epitympanicus (see t. III., Organ of hearing). Between the medial part of the tympanic part and the squamous part of the bone, the lower process of the roof of the tympanic cavity is wedged. On both sides of it, respectively, there are a stony-scaly fissure, fissura pelrosquamosa, and a stony-tympanic fissure, fissura petrotympanica (a nerve comes out of the latter - a drum string, chorda tympani, and small vessels). which forms the vagina of the styloid process, vagina processus styloidei. In a newborn, the external auditory meatus is still absent, and the tympanic part is represented by the tympanic ring, anulus tympanicus. On the inner surface of the greater tympanic spine, a spinous crest is clearly distinguishable, at the ends of which there are anterior and posterior tympanic processes, and a furrow of the malleus runs along it.

Name

Anatomy

Traces of the brain in the form of impressions (impressiones digitatae) are visible on the cerebral surface. The zygomatic process (processus zygomaticus) departs from it, which is directed forward to connect with the zygomatic bone. In the lower part there is an articular fossa for articulation with the lower jaw (fossa mandibularis).

The tympanic part (pars tympanica) is fused with the mastoid process (processus mastoideus) and the squamous part (pars squamosa), it is a thin plate that limits the front, rear and bottom of the external auditory opening (porus acusticus externus) and the external auditory canal (meatus acusticus externus) .

The stony part (pars petrosa) has the shape of a tripartite pyramid, the top of which is facing anteriorly and medially, and the base, which passes into the mastoid process (processus mastoideus), is posteriorly and laterally.

There are three surfaces: anterior, posterior and lower, as well as three edges: anterior, posterior and upper.

The anterior surface (facies anterior) is part of the bottom of the middle cranial fossa; back (facies posterior) facing back and medially, forms part of the anterior wall of the posterior cranial fossa; lower (facies inferior) facing down and visible only on the outer surface of the base of the skull.

The external relief of the pyramid is due to its structure as a receptacle for the middle and inner ear, as well as for passing blood vessels and nerves.

A thin pointed styloid process (processus styloideus) extends from the lower surface of the pyramid, serving as a site for muscle attachment. The relief of the outer surface of the pyramid is the place of attachment of the muscles, downwards it extends into the mastoid process to which the sternocleidomastoid muscle is attached.

On the mastoid process (on its anterior smooth surface) of the temporal bone, the Shipo triangle is distinguished, which is the site of operational access to the cells of the mastoid process. On the radiograph of the temporal bones, the so-called synodural angle (Citelli's angle) is distinguished. Inside, the mastoid process contains cells (cellulae mastoideae), which are air cavities that communicate with the tympanic cavity (middle ear) through the mastoid cave (antrum mastoideum).

The temporal bone is connected to the occipital, parietal, and sphenoid bones. Participates in the formation of the jugular foramen.

Canals of the temporal bone

sleepy channel, canalis caroticus, in which the internal carotid artery lies. It starts on the lower surface of the pyramid, with an external carotid foramen (foramen caroticum externum), goes vertically upward, bending at a right angle, goes forward and medially. A canal opens into the cranial cavity with an internal carotid foramen (foramen caroticum internum).
tubule of drum string, canaliculus chordae tympani, starts from the canal of the facial nerve, slightly above the stylomastoid foramen (foramen stylomastoideum), goes forward and opens into the tympanic cavity. In this tubule, a branch of the facial nerve passes - the tympanic string, which then exits the tympanic cavity through the stony-tympanic fissure (fissura petrotympanica).
facial channel, canalis facialis, in which the facial nerve passes, it begins at the bottom of the internal auditory canal, then goes horizontally from back to front. Having reached the level of the cleft of the canal of the large stony nerve, the canal goes back and laterally, at a right angle, forming a bend or knee of the facial canal. Then the channel goes back, follows horizontally along the axis of the pyramid. Then it turns vertically down, bending around the tympanic cavity, and on the lower surface of the pyramid ends with a stylomastoid opening.
musculo-tubal canal, canalis musculotubaris, has a common wall with the carotid canal. It starts in the corner formed by the anterior edge of the pyramid and the scales of the temporal bone, goes posteriorly and laterally, parallel to the anterior edge of the pyramid. Musculo-tubal canal longitudinal horizontal partition divided into two half-channels. The upper semi-canal is occupied by the muscle that strains the eardrum, and the lower one is the bony part of the auditory tube. Both canals open into the tympanic cavity on its anterior wall.
mastoid tubule, canaliculus mastoideus, originates at the bottom of the jugular fossa and ends in the tympanic mastoid fissure. A branch of the vagus nerve passes through this tubule.
tympanic tubule, canaliculus tympanicus, occurs in the stony fossa (fossula petrosa) with an opening through which a branch of the glossopharyngeal nerve enters - the tympanic nerve. After passing through the tympanic cavity, this nerve, called the small stony nerve, exits through the eponymous fissure on the anterior surface of the pyramid.
carotid tubules, canaliculi caroticotympanici, pass in the wall of the canal of the internal carotid artery near its external opening and open into the tympanic cavity. They serve to pass the vessels and nerves of the same name.
vestibule plumbing, aqueductus vestibuli, a canal in the pyramid of the temporal bone, connecting the vestibule of the bone labyrinth (the expanded part of the bone labyrinth between the cochlea of the inner ear and the bony semicircular canals) with the cranial cavity (posterior cranial fossa). It opens with a slit on the posterior surface of the pyramid of the temporal bone, behind the opening of the internal auditory meatus. The vein of the water supply of the vestibule and ductus endolymphaticus passes through the canal, which ends with a blind sac (saccus endolymphaticus), on the posterior surface of the pyramid of the temporal bone, between the opening of the internal auditory meatus and the sigmoid sinus.
snail plumbing, aqueductus cochleae, about 10 mm long, connects the vestibule of the inner ear and the posterior surface of the pyramid of the temporal bone, opening at its lower edge, below the opening of the internal auditory canal. Its inner opening is located at the beginning of the ladder of the cochlear tympanum. The vein of the cochlear tubule passes through the canal.