Stony dimple of the temporal bone. Temporal bone
sleepy channel. Connects the outer base of the skull and the top of the pyramid of the temporal bone. The internal carotid artery, the internal carotid plexus, passes through the canal.
Musculo-tubal canal. Connects the apex of the pyramid of the temporal bone and the tympanic cavity. In the canal passes the muscles that strain the eardrum, the auditory tube.
Carotid tubules. Connect the carotid canal and the tympanic cavity. Carotid-tympanic nerves and plexuses pass through the canal.
Internal auditory canal. Connects the posterior cranial fossa and the inner ear. The facial nerve, vestibulocochlear nerve, artery and vein of the inner ear pass through the canal.
front channel. Connects the posterior surface of the pyramid of the temporal bone and the stylomastoid foramen. In Canada, the facial nerve passes.
Drum string tubule. It connects the facial canal, tympanic cavity and petrotympanic fissure. In Canada, the tympanic string and the branch of the facial nerve pass.
drum tubule. Connects the lower surface of the pyramid of the temporal bone, the tympanic cavity and the anterior surface of the pyramid. In Canada, the small petrosal nerve and the branch of the glossopharyngeal nerve pass.
mastoid canal. Connects the jugular fossa and the tympanic mastoid fissure. The ear branch of the vagus nerve passes through the canal.
Plumbing vestibule. Connects the vestibule of the inner ear and the posterior cranial fossa. The vestibule water supply and the vestibule water supply vein pass through the canal.
Snail plumbing. Connects the vestibule of the inner ear and the lower surface of the pyramid of the temporal bone. The canal contains the cochlear aqueduct and the vein of the cochlear tubule.
No. 10 Sphenoid bone: its parts, holes and their purpose.
Sphenoid bone,os sphenoidale, located in the center of the base of the skull. It is involved in the formation of the lateral walls of the cranial vault, as well as cavities and fossae of the brain and facial sections of the skull. The sphenoid bone has a complex shape and consists of a body from which 3 pairs of processes extend: large wings, small wings and pterygoid processes.
Body,corpus, the sphenoid bone has the shape of an irregular cube. Inside it is a cavity - the sphenoid sinus, sinus sphenoidalis. There are 6 surfaces in the body: the upper, or cerebral; back, fused in adults with the basilar (main) part of the occipital bone; anterior, passing without sharp boundaries into the lower, and two lateral.
small wing, ala minor, is a paired plate extending from each side of the body of the sphenoid bone with two roots. Between the latter is the optic canal, canalis opticus, for passage from the orbit of the optic nerve. The anterior edges of the lesser wings are serrated; the orbital parts of the frontal bone and the ethmoid plate of the ethmoid bone are connected to them. The posterior margins of the small wings are free and smooth. On the medial side, each wing has an anterior inclined process, processus clinoideus anterior. The hard shell of the brain grows to the anterior, as well as to the posterior inclined processes.
The lesser wing has an upper surface facing the cranial cavity, and a lower one participating in the formation of the upper wall of the orbit. The space between the small and large wings is the superior orbital fissure, fissura orbitalis superior. Through it from the cranial cavity to the orbit pass the oculomotor, lateral and abducens nerves (III, IV, VI pairs of cranial nerves) and the ophthalmic nerve - I branch trigeminal nerve(V pair).
big wing, ala Major, paired, begins with a wide base from the lateral surface of the body of the sphenoid bone (Fig. 32). At the very base, each wing has three holes. Above the others and in front is a round hole, foramen rotundum, through which the second branch of the trigeminal nerve passes, in the middle of the wing - an oval hole, foramen ovale, for the III branch of the trigeminal nerve. spinous hole, foramen spinosum, smaller, located in the region of the posterior angle of the large wing. Through this opening, the middle meningeal artery enters the cranial cavity.
The large wing has four surfaces: cerebral, orbital, maxillary and temporal. On the brain surface facies cerebralis, finger-like impressions are well expressed, impressionidnes digitatae, and arterial grooves sulci arteriosi. eye surface, facies orbitalis,- quadrangular smooth plate; is part of the lateral wall of the orbit. maxillary surface, fades maxillaris, occupies a triangular area between the orbital surface above and the base of the pterygoid process below. On this surface, facing the pterygopalatine fossa, a round hole opens. temporal surface, fades tempordlis, the most extensive. infratemporal ridge, crista infratempo-ralis, divides it into two parts. The upper part is larger, located almost vertically, and is part of the wall of the temporal fossa. The lower part is located almost horizontally, forming the upper wall of the infratemporal fossa.
pterygoid process,processus pterygoideus, paired, departs from the body of the sphenoid bone at the place of the beginning of the large wing and goes vertically down. The medial plate of the process faces the nasal cavity, the lateral plate faces the infratemporal fossa. The base of the process pierces the narrow pterygoid canal from front to back, canalis pterygoideus, through which blood vessels and nerves pass. The anterior opening of this canal opens into the pterygopalatine fossa, the posterior one - on the outer base of the skull near the spine of the sphenoid bone, splna ossis sphenoidalis. The plates of the pterygoid process are distinguished: medial, lamina medidlis, and lateral lamina lateralis. The plates are fused in front. Posteriorly, the plates of the pterygoid process diverge, forming the pterygoid fossa, fossa pterygoidea. Below, both plates are separated by a pterygoid notch, incisura pterygoidea. The medial plate of the pterygoid process is somewhat narrower and longer than the lateral one and passes into the pterygoid hook below, hamulus pterygoideus.
No. 11 Pterygopalatine fossa: its walls, openings and their purpose.
pterygopalatine (pterygopalatine) fossa, fossa pterygopa-Iatina, has four walls: anterior, superior, posterior and medial. The anterior wall of the fossa is the tubercle of the maxilla, the upper wall is the inferolateral surface of the body and the base of the greater wing of the sphenoid bone, the posterior wall is the base of the pterygoid process of the sphenoid bone, and the medial wall is the perpendicular plate of the palatine bone. On the lateral side, the pterygopalatine fossa has no bone wall and communicates with the infratemporal fossa. The pterygopalatine fossa gradually narrows down and passes into the large palatine canal, canalis palatinus major, which at the top has the same walls as the fossa, and below it is delimited by the upper jaw (laterally) and the palatine bone (medially). There are five openings into the pterygopalatine fossa. On the medial side, this fossa communicates with the nasal cavity through the sphenopalatine foramen, superiorly and posteriorly with the middle cranial fossa through a round foramen, posteriorly with the region of the torn foramen via the pterygoid canal, downwardly with the oral cavity through the greater palatine canal.
The pterygopalatine fossa is connected to the orbit through the inferior orbital fissure.
№ 12 The nasal cavity, the structure of its walls. Paranasal sinuses, their meaning, variants and anomalies.
nasal cavity, cavum nasi, occupies a central position in the facial region of the skull. bony septum of the nose, septum ndsi osseum, consisting of a perpendicular plate of the ethmoid bone and an vomer, fixed at the bottom of the nasal crest, divides the bony cavity of the nose into two halves. In front, the nasal cavity opens with a pear-shaped aperture, apertura piriformis, limited by the nasal notches (right and left) of the maxillary bones and the lower edges of the nasal bones. In the lower part of the pear-shaped aperture, the anterior nasal spine protrudes forward, spina nasalis anterior. Through the back openings, or choan, choapae, the nasal cavity communicates with the pharyngeal cavity. Each choana is bounded on the lateral side by the medial plate of the pterygoid process, on the medial side by the vomer, from above by the body of the sphenoid bone, from below by the horizontal plate of the palatine bone.
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(os temporale), steam room. It distinguishes three parts located around the external auditory opening: scaly, pyramid (stony part) and tympanic (Fig. 1, 2).
The organs of hearing and balance are located in the temporal bone, vessels and nerves pass through its canals. It is involved in the formation of the temporomandibular joint.
scaly part(pars squamosa) represents a vertically located plate, connected by a free edge with the lower edge of the parietal bone and with a large wing of the sphenoid bone. Below, it is adjacent to the drum and stony parts, separated from them tympanosquamous fissure (fissura tympanosquamosa) And stony-scaly fissure (fissura petrosquamosa)[visible only on the bones of young subjects].
outdoor, temporal surface (fades temporalis), the squamous part is smooth, participates in the formation of the temporal fossa. Below it is limited zygomatic process (processus zygomaticus), which is directed anteriorly, connects to the temporal process of the zygomatic bone, forming the zygomatic arch. At the base zygomatic process distinguish the root that forms articular tubercle, and less pronounced articular tubercle (tuberculum retroarticulare), passing into the temporal line. Between the articular and articular tubercles is formed mandibular fossa (fossa mandibularis). It is covered with cartilage and articulates with the condylar process of the mandible.
Rice. 1. Temporal bone, right:
a — topography of the temporal bone;
b - outside view: 1 - scaly part; 2 - zygomatic process; 3 - articular tubercle; 4 - behind the articular tubercle; 5 - mandibular fossa; 6 - stony-scaly gap; 7 - the edge of the roof of the tympanic cavity; 8 - stony-tympanic fissure; 9 - styloid process; 10 - drum part; 11 - mastoid process; 12 - mastoid notch; 13 - external auditory meatus; 14 - mastoid opening; 15 - supra-passing spine; 16 - temporal line; 17 - furrow of the middle temporal artery;
c - anterior surface of the pyramid of the temporal bone: 1 - parietal edge; 2 - cerebral surface of the scales; 3 - stony-scaly gap; 4 - roof of the tympanic cavity; 5 - arched elevation; 6 - groove of the sigmoid sinus; 7 - mastoid opening; 8 - occipital margin; 9 - furrow of the upper stony sinus; 10 - the upper edge of the pyramid; 11 - trigeminal depression; 12 - carotid channel; 13 - rocky part; 14 - front surface of the pyramid; 15 - musculo-tubal canal; 16 - wedge-shaped edge; 17 — a furrow of a small stony nerve; 18 - furrow of a large stony nerve; 19 — a fissure of the channel of a small stony nerve; 20 — a cleft of the channel of a big stony nerve;
d - inside view: 1 - scaly part; 2 - semicircular elevation; 3 - roof of the tympanic cavity; 4 - groove of the sigmoid sinus; 5 - mastoid opening; 6 — an aperture of a tubule of a vestibule; 7 - styloid process; 8 - aperture of the tubule of the cochlea; 9 - furrow of the lower stony sinus; 10 - internal auditory meatus; 11 - furrow of the superior sagittal sinus; 12 - zygomatic process;
e - bottom view: 1 - stony-scaly crack; 2 - stony-tympanic fissure; 3 - muscular-tubal channel; 4 - internal aperture sleepy canal; 5 - the top of the pyramid; 6 - the lower surface of the pyramid; 7 - furrow of the lower stony sinus; 8 - external aperture of the carotid canal; 9 - stony dimple; 10 - condylar tubule; 11 - jugular fossa; 12 - stylomastoid opening; 13 - furrow of the occipital artery; 14 - mastoid notch; 15 - mastoid process; 16 - styloid process; 17 - tympanic scaly fissure; 18 - mandibular fossa; 19 - articular tubercle; 20 - zygomatic process
Rice. 2. Cutting the temporal bone through the tympanic cavity:
1 - arcuate elevation; 2 — a probe in a knee of the channel of a facial nerve; 3 — a furrow of a big stony nerve; 4 - semi-channel of the muscle straining the eardrum; 5 - semi-canal of the auditory tube; 6 - probe in the carotid canal; 7 - probe in the stylomastoid foramen; 8 - mastoid cells; 9 - mastoid cave
On the outer surface of the squamous part of the temporal bone passes groove of the middle temporal artery (sulcus a. temporalis mediae).
internal, brain surface (fades cerebralis) has cerebral elevations, depressions of the convolutions (finger-shaped); along it pass the furrows of the vessels of the meninges.
Human Anatomy S.S. Mikhailov, A.V. Chukbar, A.G. Tsybulkin
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.
Several channels of the temporal bone pass through the pyramid for cranial nerves and blood vessels.
sleepy channel
The carotid canal (canalis caroticus) begins on the lower surface of the pyramid with an external carotid opening, goes up, bends almost at a right angle, then goes medially and forward. The channel ends with an internal carotid foramen at the top of the pyramid of the temporal bone. Through this canal, the internal carotid artery and nerves of the carotid plexus pass into the cranial cavity.
Through the carotid canal passes the internal carotid artery, the internal carotid (autonomous) nerve plexus.
Carotid tubules
Carotid-tympanic tubules (canaliculi caroticotympanici), 2-3 in number, begin on the wall of the carotid canal (near its outer opening) and penetrate into the tympanic cavity.
Carotid nerves and arteries are located in these tubules.
Musculo-tubal canal
The musculo-tubal canal (canalis musculotubularis) has a common wall with the carotid canal, begins at the top of the pyramid of the temporal bone, goes back and laterally and opens into the tympanic cavity.
It consists of two sections: the semicanal of the auditory tube (semicanalis tubae auditivae) and the semicanal of the muscle stretching the eardrum (semicanalis m. tensoris tympani). 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.
A horizontal partition divides it into two parts. Above is the semi-canal of the muscle that strains the eardrum (semicanalis musculi tensoris tympani), containing the muscle of the same name.
Below is the semicanal of the auditory tube (semicanalis tubae auditivae).
In the muscular-tubal canal passes the muscle that strains the tympanic membrane (semi-canal of the muscle that strains the eardrum), the auditory tube (semi-canal of the auditory tube).
front channel
The facial nerve canal (canalis n. facialis) begins at the bottom of the internal auditory meatus and goes forward and laterally to the level of the cleft of the canal of the large stony nerve. Here a bend is formed - the knee of the facial canal (geniculum n. facialis). From the knee, the canal goes at a right angle laterally and backward along the axis of the pyramid, then changes its horizontal direction to a vertical one and ends at the posterior wall of the tympanic cavity with an awl-mastoid opening.
The facial canal connects the posterior surface of the pyramid of the temporal bone (internal auditory meatus) and the stylomastoid foramen (external base of the skull).
The facial nerve passes through the facial canal VII pair cranial nerves).
Drum string tubule
The tubule of the drum string (canaliculus chordae tympani) starts from the canal of the facial nerve slightly above the stylomastoid foramen and ends in the petrotympanic fissure.
It contains a branch of the facial nerve - the drum string.
drum tubule
The tympanic tubule (canaliculus tympanicus) is very narrow; 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
The mastoid tubule (canaliculus mastoideus) 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.
The auricular branch of the vagus nerve passes through this tubule.
Temporal bone, os temporale, - a paired bone, is part of the base and lateral wall of the brain skull and is located between the sphenoid (front), parietal (top) and occipital (rear) bones.
Functions of the temporal bone
The temporal bone is a bone receptacle for the organs of hearing and balance; vessels and nerves pass through its canals.
The temporal bone forms a joint with the lower jaw and connects to the zygomatic bone, forming the zygomatic arch, circus zygomaticus.
The structure of the temporal bone
In the temporal bone, a pyramid (stony part) with a mastoid process, tympanic and squamous parts are distinguished.
Pyramid
or rocky part pars petrosa, 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.
drum part
pars tympanica, 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, pdrus acusticus externus, on three sides (front, bottom and back). The continuation of this opening is the external auditory meatus, meatus acusticus externus, 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, fissura tympanoma-stoidea, is formed.
scaly part
pars squatnosa, is a convex outwards plate with a beveled free upper edge. It is superimposed like scales (squama - scales) on the corresponding edge of the parietal bone and the large wing of the sphenoid bone, and below it is connected to the pyramid, mastoid process and tympanic part of the temporal bone.
Canals of the temporal bone
Sleepychannel. Connects the outer base of the skull and the top of the pyramid of the temporal bone. The internal carotid artery, the internal carotid plexus, passes through the canal.
Musculo-tubal canal. Connects the apex of the pyramid of the temporal bone and the tympanic cavity. In the canal passes the muscles that strain the eardrum, the auditory tube.
Carotid tubules. Connect the carotid canal and the tympanic cavity. Carotid-tympanic nerves and plexuses pass through the canal.
Internal auditory canal. Connects the posterior cranial fossa and the inner ear. The facial nerve, vestibulocochlear nerve, artery and vein of the inner ear pass through the canal.
front channel. Connects the posterior surface of the pyramid of the temporal bone and the stylomastoid foramen. In Canada, the facial nerve passes.
Drum string tubule. It connects the facial canal, tympanic cavity and petrotympanic fissure. In Canada, the tympanic string and the branch of the facial nerve pass.
drum tubule. Connects the lower surface of the pyramid of the temporal bone, the tympanic cavity and the anterior surface of the pyramid. In Canada, the small petrosal nerve and the branch of the glossopharyngeal nerve pass.
mastoid canal. Connects the jugular fossa and the tympanic mastoid fissure. The ear branch of the vagus nerve passes through the canal.
Plumbing vestibule. Connects the vestibule of the inner ear and the posterior cranial fossa. The vestibule water supply and the vestibule water supply vein pass through the canal.
Snail plumbing. Connects the vestibule of the inner ear and the lower surface of the pyramid of the temporal bone. The canal contains the cochlear aqueduct and the vein of the cochlear tubule.
| Temporal bone, (os temporale). Outside surface. Right view. 1-squamous part (scales) of the temporal bone; |
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Temporal bone(os temporale). Inner surface. 1-squamous part of the temporal bone; |
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Temporal bone(os temporale). Saw through the tympanic cavity along the long axis of the pyramid (right bone). 1-scales of the temporal bone |
The temporal bone, os temporale, steam room, is very complex in structure, since the organs of hearing and balance are enclosed in its thickness, and, in addition, the bone is pierced by a number of channels through which the vessels and nerves pass. The temporal bone is located in the lateral parts of the skull between the occipital, parietal and sphenoid bones, complementing the cranial vault with one part, the base of the skull with the other. The temporal bone is connected to the facial skull: with the help of a joint - with the lower jaw, and a seam - with the zygomatic bone.
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The temporal bone consists of several fused parts. When considering the temporal bone from the side of the outer, temporal surface, at its lower edge, there is a large opening, which is called the external auditory opening, porus acusticus externus. The hole is surrounded by four components of the temporal bone: from above and in front - a flat, with a pointed edge of the scales of the temporal bone, squama temporalis, in front and below - a small, in the form of a gutter, plate - the tympanic part, pars tympanica, behind - a powerful bone protrusion - the mastoid part , pars mastoidea, from the inside - in the form of a pyramid, tapering in the direction from the mastoid part obliquely inward and anteriorly - the stony part or pyramid, pars petrosa s. pyramis. The scales of the temporal bone, squama temporalis, has the shape of a semicircular bone plate, facing its smooth temporal surface, fades temporalis, outwards and the inner, cerebral surface, fades cerebralis, into the cranial cavity. The semicircular shape of the edge limiting the scales is not the same everywhere; the anterior and posterior sections of the edge are more serrated and less pointed on the inside than the upper section. The front edge is connected to the scaly edge of the large wing of the sphenoid bone and is called the main edge, margo sphenoidalis; the upper posterior edge, connecting with the scaly edge of the parietal bone, is called the parietal edge, margo parietalis. The posterior-lower part of the scale passes into the mastoid part.
In children, at the junction of these parts, there is a scaly-mastoid suture, sutura squamomastoidea, obliquely directed from top to bottom and anteriorly. The remnants of this suture are sometimes preserved in adults. A little higher and along it is the temporal line, the anterior end of which approaches the root of the zygomatic process of the temporal bone, processus zygomaticus ossis temporalis. The zygomatic process departs with two roots: posterior and anterior. It runs horizontally, first outward, and then at an angle anteriorly, and ends with a jagged end. Lastly, it connects to the temporal process of the zygomatic bone, forming with it the zygomatic arch, arcus zygomaticus. Below the zygomatic process and in front of the external auditory canal, is the articular fossa of the lower jaw, fossa mandibularis. In the anterior sections, the fossa is limited by a well-marked articular tubercle, tuberculum articulare; in the posterior - smaller, behind - the articular process, processus retroarticularis. The anterior part of the fossa and the articular tubercle are covered with cartilage. In the posterior part of the outer surface, fades temporalis, the scales of the temporal bone bear the groove of the middle temporal artery, sulcus arteriae temporalis mediae. This furrow rises upward and branches out in the upper segment of the scale.
cerebral surface, fades cerebralis, the bones are somewhat concave, have a well-defined, deep arterial groove in the anterior section, sulcus arteriosus (meningeus) (the place where the meningeal artery of the brain fits), traces of depression of the cerebral convolutions - digital impressions, impressiones digitatae, and between the last protrusions - cerebral elevations , juga cerebralia. Stony part or pyramid, parspetrosa s. pyramis, has the form of a three-sided pyramid, lying in a supine position, so that its base, basis pyramidis, is directed outward and connects to the mastoid and squamous parts of the temporal bone. At the site of attachment of the base of the pyramid to the squamous part in childhood there is a gap, flssura petrosquamosa, over the years it is filled with bone tissue, and thus the border between these two parts disappears.
The top of the pyramid has an uneven edge. It is directed forward and inward, towards the lateral surface of the bodies of the sphenoid and occipital bones. The gap remaining between them on the whole skull is called torn hole, foramen lacerum (Fig. 124), filled with fibrous cartilage, fibrocartilago basilaris. A large internal opening of the canal opens in the apex area carotid artery, foramen caroticum intemum. The upper corner of the pyramid, angulus superior pyramidis, protrudes freely into the cranial cavity at the border of the anterior and posterior surfaces of the pyramid, fades anterior and fades posterior pyramidis. The upper stony furrow, sulcus petrosus superior, runs along the upper corner of the pyramid, a trace of the venous sinus of the same name that lies here. With an internal segment, the anterior angle is connected to the edge of the large wing of the sphenoid bone with the help of cartilage, forming the main stony synchondrosis, synchondrosis sphenopetrosa. The outer segment connects the anterior angle with the scales of the temporal bone, forming a stony-scaly fissure, fissura petrosquamosa.
Near the medial end of the stony-squamous fissure, in the corner where the front corner of the pyramid converges with the anterior edge of the scale, one can see orifice of the musculoskeletal canal, canalis musculotubarius. The latter, located obliquely outward and backward, is divided by a horizontally standing thin bone plate - the septum of the musculo-tubal canal, septum canalis musculotubarii, into two parts: the upper one is the semi-canal of the muscle that strains the eardrum, semicanalis musculi tensoris tympani, and the lower one is the semi-canal of the auditory (Eustachian ) pipes, semicanalis tubae auditivae Eustachii. Both semi-canals lead to the middle ear cavity. The back corner of the pyramid, angulus posterior pyramidis, is located on the border of its back and lower surfaces, facies posterior et facies inferior pyramidis. It is adjacent to the lateral margins of the partes basilaris and lateralis ossis occipitalis. The inner part of the posterior angle adjoins the pars basilaris ossis occipitalis, and a petrooccipital fissure, fissura petrooccipitalis, is formed here, made by cartilage connecting both bones - synchondrosis petrooccipitalis. On the cerebral surface of this part of the posterior angle passes the lower stony furrow, sulcus petrosus inferior. The latter, connecting with the sulcus of the same name on the adjacent part of the occipital bone, is the site of the temporal sinus (sinus petrosus inferior).
At the outer end of the furrow, at the posterior corner of the pyramid, there is a small depression, at the bottom of which a small external opening of the cochlear canal, apertura externa canaliculi cochleae, opens. (Here are v. canaliculi cochleae and ductus perilymphaticus coming from the cavity of the inner ear). The lateral part of the posterior corner of the pyramid is adjacent to the pars lateralis ossis occipitalis. There is a small jugular notch, incisurajugularis, which corresponds to the same notch on the occipital bone and together with it forms the jugular foramen, foramen jugulare, on the whole skull.
At these three corners of the pyramid, three of its surfaces converge: front, back and bottom. The first two face the cranial cavity, the latter is directed towards the outer surface of the base of the skull. The anterior surface of the pyramid, fades anterior pyramidis, is uneven, inclined anteriorly. Outside, it borders on scales, forming a stony-scaly gap, fissura petrosquamosa; from the inside, it borders on the body of the main bone, not reaching it and forming here the ragged hole described above, foramen lacerum, with the uneven edge of its top. The anterior-inferior and posterior-superior boundaries are the corresponding corners or edges of the pyramid. On the anterior surface of the pyramid, near the apex, there is an impression of the trigeminal nerve, impressio nervi trigemini, - the imprint of the gasser ganglion of the trigeminal nerve (ganglion Gasseri) adjacent here.
Slightly away from the middle of the front surface of the pyramid, a semicircular elevation, eminentia arcuata, protrudes - the relief of the upper semicircular canal. The area of the anterior surface, located between the elevation and the stony-scaly fissure (fissura etrosquamosa), is the roof of the tympanic cavity, legmen tympani; which is a thin plate that forms the upper wall of the middle ear cavity. Tegmen tympani, with its front edge, enters the gap between pars tympanica behind and pars squamosa in front, forming a ridge visible in the fossa mandibularis region, called processus inferior tegmenis tympani (s. crista tegmcntalis) (see more about this when describing pars tympanica).
Slightly inwards and downwards from eminentia arcuata, two holes are visible. One of them is located more medially and is the opening of the facial nerve canal, hiatus canalis facialis. Through this hole, a branch of the facial nerve emerges - a large stony nerve, nervus petrosus superficialis major, which lies in the corresponding groove - sulcus nervi petrosi superficialis majoris, running longitudinally inward and anterior to the hiatus canalis facialis.
The other opening is located lateral and is the superior opening of the tympanic tubule, apertura superior canaliculi tympanici. Through this hole, a small stony nerve emerges - nervus petrosus superficialis minor, which lies in the groove of the same name - sulcus nervi petrosi superficialis minoris. This groove, heading inward and anteriorly from the pyramid, runs parallel and outward from the sulcus nervi petrosi superficialis majoris. Inside from the upper corner, closer to the middle of the posterior surface, there is a rather wide internal auditory opening, porus acusticus internus. It opens into a channel going inside the rocky part. This channel is called internal auditory canal, meatus acusticus interims. (See "The Ear" for its further move inside the rocky part.)
Outside and behind the porus acusticus internus, a small slit-like opening is visible, called external opening of the water supply-vestibule, apertura externa aquaeductus vestibuli, which is the exit point of the internal lymphatic duct, ductus endolymphaticus, from the cavity of the inner ear. Slightly above the opening of the water supply, at the upper corner of the pyramid, is located subsemicircular fossa, fossa subarcuata, clearly visible in young people. The lower surface of the pyramid, fades inferior pyramidis, is directed downward and faces the outer surface of the base of the skull; outside and somewhat in front, this surface is in contact with the tympanic part of the temporal bone. It carries a large number of holes, recesses and protrusions.
The central place on the lower surface of the pyramid is occupied by a large round hole, which is the entrance to the carotid canal, the external opening of the carotid canal, foramen caroticum externum. (The internal carotid artery and the nerve plexus enter through this opening.) Behind and outward from the foramen caroticum externum, separated from it by a crest, there is a wide jugular fossa, fossa jugularis, reaching the posterior edge of the lower surface of the stony part, where there is a jugular notch, incisura jugularis. It contains the bulb of the jugular vein. At the bottom of the jugular fossa, closer to its anterior edge, is the groove of the mastoid tubule, sulcus canaliculi mastoidei, ending with the opening of the mastoid tubule, canaliculus mastoideus.
On the scallop separating the fossa jugularis from the foramen caroticum externum, there is a barely noticeable stony dimple, fossula petrosa, leading to the lower opening of the tympanic tubule, apertura inferior canaliculi tympanici. (A. tympanica inferior and n. tympanicus pass here - from the stony node.) At the very base of the pyramid, on the outer part of the lower surface, the styloid process protrudes downward and anteriorly, processus styloideus, which is semi-circled in front by a bony vagina, vagina processus styloidei, formed by the tympanic part of the temporal bone.
Near the styloid process, on the border with the mastoid process, processus mastoideus, is the stylomastoid opening, foramen stylomastoideum, the exit point of the facial nerve and blood vessels. In the pyramid of the temporal bone there are a number of channels through which the vessels and nerves pass, and the organ of hearing and the organ of balance of the body are laid , so the pyramid has such a complex structure. All these formations are visible on special preparations of cuts of the temporal bone, carried out in various directions.
1.Formations related to the structure of the organs of hearing and balance:
but). external auditory canal, porus acusticus externus, and its continuation into the external auditory canal, meatus acusticus externus, are the bony parts of the outer ear;
b). tire of the tympanic cavity, tegmen tympani, is upper wall the cavity of the middle ear, where the canalis musculo-tubarius opens, lying on the outer edge of the anterior corner of the pyramid;
in). inner ear cavity(labyrinth) is indicated on the anterior surface of the pyramid by a semicircular eminence, eminentia arcuata, where the superior semicircular canal fits, and on the posterior surface by a fossa, fossa subarcuata.
Small holes on the back of the pyramid, apertura externa canaliculi cochleae and apertura externa aquaeductus vestibuli, lead to the inner ear; they contain vessels and lymphatic ducts through the porus acusticus internus passing the auditory and facial nerves.
2. facial nerve canal(fallopian canal), canalis facialis (Falloppii), inside the petrous part of the temporal bone. It begins with an opening in the bottom of the internal auditory meatus, in the region of its upper deepening - area facialis (see "Ear"), and continues the direction of the internal auditory meatus forward and outward under the anterior surface of the stony part. Here, to the front surface of the pyramid, a branch departs from it, ending with a hole - hiatus canalis facialis; the canal itself, turning outward and backward, forms at the place of rotation the knee of the auditory nerve canal, geniculum canalis facialis.
After the formation of the knee, the canal follows backwards and somewhat downwards and, having reached the posterior section of the inner wall, cavum tympani, passes into the vertical part. Then it goes down and opens behind the base of the styloid and anterior to the mastoid processes - the stylomastoid opening, foramen stylomastoideum. The upper end of the vertical part of the canal forms a protrusion of the facial nerve canal, prominentia canalis facialis, located in the posterior part of the medial wall of the inner ear. A little lower, the canal of the facial nerve gives a branch of the Canadian drum string, canaliculus chordae tympani, through which the nerve passes - the drum string, chorda tympani, and which ends in fissura petrotympanica (Glaseri).
3. drum tubule, canaliculus tympanicus, passes a branch of the glossopharyngeal nerve. The tubule begins with the lower opening of the tympanic tubule at the bottom of the stony fossa, fossula petrosa (from the side of the lower surface of the stony part), and, heading arcuately backwards, upwards and then forward, opens with the upper opening of the tympanic tubule, apertura superior canaliculi tympanici (on the anterior surface of the stony part) . Canaliculus tympanicus communicates with canalis nervi facialis Falloppii in the region of his knee.4. The carotid canal, canalis caroticus, is short, wide and curved. Through it pass the internal carotid artery and its venous and nervous plexuses. The channel begins with a hole located on the lower surface of the pyramid - foramen caroticum externum.
Further, the canal rises upward, then forms a bend almost at a right angle and, heading horizontally anteriorly and inside, opens with the internal opening of the carotid canal, foramen caroticum internum. These tubules are short, go to the anterior wall of the cavum tympani, bypassing the wall of the carotid canal from above. Opening in the anterior wall of the cavum tympani, they pass the branches of the internal carotid artery and the superior and inferior carotid tympanic nerves.
mastoid part, pars mastoidea, located posterior to the external auditory canal. Outside, it smoothly turns into scales, and from the inside - into the stony part. From top to bottom, the mastoid part faces a free convex, posteriorly and outwards - a rough surface. The posterior, occipital margin, margo occipitalis, connects to the mastoid margin of the occipital bone, forming the occipital-mastoid suture, sutura occipitomastoidea.
Top edge, together with the posterior portion of the parietal edge of the scales, forms the parietal notch, incisura parietalis. This notch is performed by the mastoid angle of the parietal bone, angulus mastoideus, which is connected to the mastoid part with the help of the mastoid-parietal suture, suturaparietomastoidea. In front, in the upper section, the mastoid part passes into the scales, in the lower part it borders on the tympanic part, forming with it the tympanic-mastoid fissure, fissura tympanomastoidea. In the anterior section, which makes up the upper-posterior part of the edge of the external auditory opening, there is a small protrusion - the supra-inlet spine, spina suprameatum, and near it posteriorly - the mastoid fossa, fossa mastoidea.
The rough anterior-inferior section of the outer surface ends with a blunt and powerful mastoid process, processus mastoideus, which is directed obliquely anteriorly and downward and is well palpable through the skin, in adults it varies, the degree of its development in children of the first years of life is weakly expressed (Fig. 83 ). In the posterior-lower section of the outer surface of the process there is a mastoid opening, foramen mastoideum, belonging to the group of graduates' openings, emissaria Santorini; it penetrates through the entire thickness of the bone and opens on the inner surface of the mastoid process. This hole is not constant in size and position: sometimes it is one and is located in the region of the sutura squamomastoidea, sometimes there are several.
From the outside and from below, the mastoid process bears a deep mastoid notch, incisura mastoidea, the place where the digastric muscle (m. digastricus) begins. The groove of the occipital artery, sulcus arteriaeoccipitalis, runs medially and parallel to the notch. On the inner, cerebral, surface of the mastoid part there is an S-shaped groove, sulcus sigmoideus, - the place of occurrence of the venous sinus of the same name - sinus sigmoideus. Very often, the inlet of the foramen mastoideum mentioned above opens into the same furrow. Processus mastoideus belongs to the group of pneumatic bones. As can be seen from the drawings depicting the cut of the mastoid process, it has a large number of interconnected cells, cellulae mastoideae, lined with a mucous membrane. The cells are filled with air penetrating here from the cavity of the middle ear. In the anterior upper corner, inside the mastoid process, there is a large cell called the cave of the tympanic cavity, antrum tympanicum, communicating, on the one hand, with the cavity of the middle ear, and on the other hand, with the cells of the mastoid process.
The number and size of cells may vary from individual to individual. The tympanic part, pars tympanica, is laid in the period embryonic development in the form of a horseshoe-shaped semicircle - a tympanic ring, annuhis tympanicus, forming the lower periphery of the external auditory canal. The ends of the semicircle: the anterior, greater tympanic spine, spina tympanica major, and the posterior, lesser tympanic spine, spina tympanica minor, limit a gap called the tympanic notch, incisura tympanica (Rivini), over which (above both spines) hangs the lower edge of the scaly part of the temporal bones, thus closing the semicircle from above. The tympanic sulcus, sulcus tympanicus, runs along the circumference of the inner surface of the ring, which is the site of attachment of the tympanic membrane.
On the inner surface of the spina tympanica major there is an oblique spinous scallop, crista spinarum, the sharp ends of which are called: the anterior - processus tympanicus anterior, and the posterior - processus tympanicus posterior. A groove runs along the ridge and below it - sulcus mallei. Due to the growth of bone substance from the side of the outer surface of the semicircle, the latter takes the form of a trough-shaped plate, which on the temporal bone of an adult forms the anterior, lower and part of the posterior wall of the external auditory opening, porus acusticus externus, and the outer auditory canal, meatus acusticus externus. With the lengthening of the bony groove of the tympanic part, the external auditory canal also lengthens with age: thus, the tympanic membrane, which lies more superficially in children, due to this goes into depth.
The upper anterior edge of the tympanic part is separated from the scaly part for a long distance by the front edge of the stony part wedged between them - the lower process of the roof of the tympanic cavity, processus inferior tegmenis tympani (s. crista tegmentalis). Between this process in front and pars tympanica behind, a stony-tympanic fissure is formed, fissura petrotympanica (Glaseri), through which small vessels and a nerve pass - a drum string, chorda tympani. Between the process at the back and the pars squamosa at the front, another gap is formed - stony-scaly, fissura petrosquamosa, made connective tissue.
The posterior lower edge of the tympanic part borders on the mastoid part of the temporal bone, forming at the point of contact a tympanic-mastoid fissure, fissura tympanomastoidea, in the depth of which the outlet of the mastoid canaliculus, canaliculus mastoideus, begins in the fossa jugularis. The edge is pointed and stretched downwards in the form of a ridge, crista peirosa, part of which is the most developed at the base of the processus styloideus, is called the styloid sheath, vagina processus styloidei. The lower surface of the tympanic part and the fossa at the root of the zygomatic process of the squamous part form the articular fossa of the lower jaw, fossa mandibularis, at the bottom of which are fissura petrotympanica (Glaseri) and fissura petrosquamosa. This fossa is divided by the glazing fissure into two parts - anterior and posterior.
The anterior part, lined with articular cartilage, faces the cavity of the mandibular joint, it is called inside- or intracapsular part, pars intracapsularis; back - located outside the joint and is called out- or extracapsular part, pars extracapsularis (see "Mandibular joint").