Formation of the temporal bone. Temporal bone of the skull. Temporal bone: anatomy
Temporal bone canals and their contents
| Channel name | Beginning of the channel | End of the channel | Content |
|
| Facial canal (canalis facialis) | Internal auditory canal, meatus acusticus internus | Stylomastoid foramen, foramen stylomastoideum | - facial nerve, n/facialis (VII pair) - ganglion geniculi; - stylomastoid arteries and veins, s., vv. stylomastoideae | |
| Sleepy channel(canalis caroticus) | The external carotid foramen, foramen caroticum externum, is anterior to the jugular fossa of the outer base of the skull. It goes up, bends at a right angle, goes forward and medially. Opens into the internal carotid foramen. | Internal carotid foramen, foramen caroticum internum | -internal carotid artery, a.carotis interna-venous plexus of the carotid canal, plexus venosus caroticus internus-internal carotid plexus, plexus caroticus internus (from ganglion superius truncus sympathicus) | |
| Muscular- pipechannel(canalis musculotubarius)a) semicanalis m.tensoris tympanib) semicanalis tubae auditivae | Tympanic cavity, cavitas tympani | The tip of the pyramid, apex puramis | Tensor tympani muscle m.tensor tympani auditory tube pars ossea tubae auditivae |
|
| Carotid-tympanic tubules(canaliculi caroticotympanici) | Sleepy canal, canalis caroticus | Tympanic cavity, cavitas tympanica | -Carotid-tympanic arteries, aa.carotico-tympanici (from a. carotis interna); -carotid-tympanic nerves, nn. Caroticotumpanici (from pl. caroticus internus et n. tympanicus) | |
| Mastoid canalec(canaliculus mastoideus) | Jugular fossa, fossa jugularis (foramen mastoideum) | Mastotympanic fissure, fissura tympanomastoidea (apertura canaliculi mastoidei) | -auricular branch of the vagus nerve (X) ramus auricularis n. vagi | |
| Channelbigrockynerve (canalis nervi petrosi majoris) | Facial canal in the area, geniculum canalis facialis | Cleft of the greater petrosal nerve, hiatus canalis nervi petrosi majoris | -greater petrosal nerve, n. petrosus major (branch n. facialis) | |
| Drum string channel(canaliculus chordae tympani) | Facial canal in the area of the stylomastoid foramen, foramen stylomastoideum | Petrostympanic fissure, fissura petrotympanica | -drum string, chorda tympani (branch of n. facialis VII pair) | |
| Tympanic tubule (canaliculus tympanicus) | The lower surface of the pyramid of the temporal bone. Stony dimple, fossula petrosa (apertura inferior canaliculi tympanici) | Cleft of the lesser petrosal nerve, hiatus canalis n. petrosi minoris | - tympanic nerve, n. tympanicus (branch n.glossopharyngeus IX pair) | |
| Internal auditory canal (meatus acusticus internus) | Posterior cranial fossa and inner ear. | The porus acusticus internus begins on the posterior surface of the pyramid and ends in the inner ear. | Facial nerve (VII), vestibulocochlear (VIII), artery and vein inner ear. | |
| Aqueduct of the vestibule (aqueductus vestibuli) | The vestibule of the inner ear and the posterior cranial fossa (external aperture of the vestibular aqueduct). | From the vestibule to the external aperture of the vestibular aqueduct, aperture aqueductus vestibule externa. | The aqueduct of the vestibule (endolymphatic duct) and the vein of the vestibule aqueduct. | |
| Plumbing snail (aqueductus cochleae) | The vestibule of the inner ear and the lower surface of the pyramid of the temporal bone (outer aperture of the cochlear canaliculus). | From the vestibule to the external aperture of the cochlear canaliculus, aperture canalis cochleae externa. | Cochlear aqueduct (perilymphatic duct) and cochlear canaliculus vein. |
Peculiarities of childhood
The main bone develops on a cartilaginous basis from individual ossification nuclei. Initially formed from two parts (the base and the anterior part of the main bone), each of which has its own ossification nuclei that appear in different terms by the 3-4th month of intrauterine development. Individual structures the bones fuse with each other and with the body of the bone during the fourth to sixth months of intrauterine life. Ossification continues in the postnatal period until the final formation of the skull. The sinus of the main bone is also formed mainly after birth: in newborns it is represented by minor protrusions of the mucous membrane in the area of the formation of the sinuses, which reach the body of the bone by 8 - 10 years, and in general the formation of the sinuses lasts until 12 - 15 years. The temporal bone develops from three initially interconnected bone structures and in newborns it consists of three bones - the squamosal, the pyramid (petrous part) and the tympanic part, separated by visible slits. The external auditory canal in the tympanic part is absent (in this place there is a funnel-shaped depression filled with caseous substance) and acquires its final shape and size by the age of 6 years. The mastoid process is also weakly expressed, which after birth develops under the influence of the traction of the sternocleidomastoid muscle; its pneumatization occurs after 3 years of age. Other bone structures and canals develop at different times and acquire relief expression by the age of 6, when the bone takes its final shape. Final control questions: 1. What parts does the main bone consist of? 2. What surfaces does the body, large and small wings of the main bone have? 3. What holes, grooves, slits, canals and apertures does the main bone contain? 4. What features of the main bone can be noted on an x-ray of the skull? 5. Borders of the temporal bone on the skull. 6. Parts of the temporal bone. 7. Surfaces and edges of the rocky part. 8. Anatomical characteristics of the squamous, petrous and tympanic parts of the temporal bone. 9. Canals of the temporal bone, their contents. 10. The walls of the tympanic cavity and formations located on them. 11. The order, timing of ossification and synostosis of the sphenoid and temporal bones. 12. Main variants, anomalies and malformations of the sphenoid and temporal bones. 13. Anatomical formations on a plain radiograph of the skull. 14. Tests and situational tasks on the topic.
SELF-TRAINING PROGRAM.
| Training assignments | Specification of tasks |
| 1. Study wedge-shaped structure bones. | 1. Find and name its parts and determine their location on the skull, relationships with other bones.2. Name the cavities in the formation of which parts of the main bone take part.3. Study the structure of the body, large and small wings, pterygoid processes of the main bone. Name their contents.4. Find and name the holes, canals and fissures of the main bone. |
| 2. Study the structure of the temporal bone. | 1. Find the boundaries of the temporal bone on the skull.2. Find the components of the temporal bone.3. Let's consider the structure of the scales of the temporal bone.4. Consider the structure of the tympanic part of the temporal bone.5. Consider the structure of the petrous part of the temporal bone. |
| 3. Find and show the canals of the temporal bone and determine their contents. | 1. Find the sleepy channel.2. Find the canals of the cranial nerves and their branches. |
Topic 11. BONES OF THE FACIAL SKULL. TOPOGRAPHY OF THE ORBIT, BONE NASAL CAVITY, PARASAL SINUSES. connections of the skull bones, temporomandibular joint
Issues covered
The structure of the lower and upper jaws, zygomatic, nasal, palatine, lacrimal, hyoid bones, vomer, inferior nasal concha. The structure of the orbit, the bony nasal septum. The inflow sinuses of the nose (maxillary, sphenoid, frontal, cells of the ethmoid bone), their communications. Development, age-related characteristics, variants and anomalies of development. Interpretation of functional research methods. Connections of the skull bones: classification. Syndesmoses of the skull: sutures, their types and characteristics. Synchondrosis of the skull: their types, characteristics, age characteristics. Temporomandibular joint, its characteristics. Age characteristics connections of the skull: fontanelles, their types, structure, timing of ossification. Development, formation and involutional changes of joints. X-ray anatomy of the skull.
Relevance of the topic
Small bones facial skull form important architectural parts of the face, ensuring the perfection of its structural basis and unique individuality. At the same time, they provide the mechanical strength of the skull. Participating in the formation of its cavities (orbit, nasal and oral), they serve to protect and normal functioning of the initial parts of the digestive, respiratory systems and sensory organs (sight, smell, taste). The slits, openings and channels that have the cavities of the skull provide the passage of neurovascular bundles for the innervation of these organs. Knowing them anatomical structure necessary both for the study of other branches of anatomy and in practical medicine. The upper and lower jaws and the palatine bones belong to the bones of the facial skull. They take part in the formation of cavities for the initial sections digestive system(oral cavity) and respiratory (nasal cavity) systems, which determines their structure. In the structure of these bones, the most pronounced signs of the evolution of the skull are characteristic of the skull of Homo sapiens and are associated with the development of articulate speech, the development of the brain, and the consumption of processed food. Knowledge of the structure of these bones is necessary for studying other human systems (dental, digestive, respiratory), as well as for doctors of other specialties (therapists, surgeons, pediatricians, etc.). The study of the connections of the skull bones and the temporomandibular joint is necessary to understand the morphofunctional features of the atlanto-occipital and atlanto-axial joints and to provide correct medical care in case of disruption of their normal functioning in surgical and trauma clinics, and knowledge of the connections of the skull bones, the structure and biochemical characteristics of the temporomandibular joint is necessary for neurosurgeons, maxillofacial surgeons and dentists.
Educational-target tasks
Study the structure of the small bones of the skull. Teach students to find these bones on a whole skull. To study the structure of the walls of the orbit, nasal cavity and hard palate, their communication with each other and with the pterygopalatine fossa. To study the anatomical structure of the jaw and palatine bones separately and the constructive relationship between themselves and with other bone formations of the skull. Study the anatomical structure of the joints of the skull bones, including the temporomandibular joint. Please note that all types of joints are found between the bones of the skull: syndesmoses, synchondroses, synostoses and diarthrosis. When examining the temporomandibular joint, note the presence and function of the intra-articular disc and the features of the ligamentous apparatus of the joint. To teach students to correctly interpret X-ray images of the head skeleton in order to distinguish the X-ray picture of sutures and vascular canals from skull cracks, the ability to find, name and show on X-ray images the image of individual bones and their parts, joints of the skull bones. The student must know: – Latin terminology of this topic (names of bones, their parts and anatomical formations); – classification of small bones of the facial skull; – correct anatomical position of the small bones of the skull and their relationship with adjacent bone formations; – anatomical formations of small bones of the facial skull; – the structure of the walls of the orbit, its openings, slits, canals and contents; – the structure of the walls of the nasal cavity, openings, canals and their contents; – the boundaries of the nasal passages and sinuses that open in them; – structure of the bony palate, openings, canals and their contents; – communications between the cavities of the skull (orbit, nasal cavity and mouth); – classification of the maxillary, mandibular and palatine bones; – the correct anatomical position of these bones and their relationship with adjacent bones; – parts of the bones being studied and their anatomical formations; – buttresses of the upper and lower jaws. The student must be able to name and show: – correct functional position of the small bones of the facial skull; – boundaries of the small bones of the facial skull on the skull; – belonging of the small bones of the facial skull to the right or left half of the skull; – anatomical formations of these bones; - bones that form the walls of the orbit and the entrance to it; goshshchd - holes, slits and canals of the orbit; – the bones that form the walls of the nose, the inlet and outlet openings of the nasal cavity, show the openings and canals of the nasal cavity; – paranasal sinuses and places of their communications with the nasal passages; – bones forming the bony palate, canals of the bony palate; – correct functional position of the maxillary and palatine bones on the skull; – boundaries of the maxillary and palatine bones on the skull; – affiliation upper jaw and the palatine bone to the right or left half of the skull; – anatomical formations of the maxillary, mandibular and palatine bones; – buttresses of the upper and lower jaws. – joints of the skull bones; – ligaments that strengthen the temporomandibular joint; – X-ray images of the connections of the spinal column with the skull and the connections of the skull bones. – dissect the joints of the skull, the temporomandibular joint, the atlanto-occipital and atlanto-axial joints. Issues of monitoring the initial level of knowledge: 1. Classification of the main bone. 2. Borders of the main bone on the skull. 3. Anatomical formations of the sphenoid bone. 4. Relationships of the main bone with other bone formations of the skull. 5. Parts of the main bone. 6. Surfaces of the body of the main bone. 7. Holes, grooves, slits, canals and apertures of the main bone. 8. Features of the main bone on radiographs of the skull. 9. Anatomical parts of the temporal bone, its functional features, the temporal bone belongs to the right or left half of the skull. 10. The structure of the scaly part of the temporal bone. 11. Anatomical characteristics of the petrous part of the temporal bone. 12. Structure of the tympanic part of the temporal bone. 13. Canals of the temporal bone and their contents. 14. Walls of the tympanic cavity and anatomical formations on them. 15 Features of the temporal bone in an x-ray image. 16. Anatomical structure occipital bone. 17. Anatomical structure lower jaw. 18. Main formations of the temporal bone. 19. Features of the anatomical structure of 1-2 cervical vertebrae. 20. Method of preparation of the temporomandibular, atlanto-occipital and atlanto-axial joints. Practical equipment of the lesson: skeleton, skull, individual bones of the facial skull (upper and lower jaws, zygomatic, nasal, lacrimal bones, vomer, inferior turbinates, hyoid bone).
Independent work of students
During independent work, students use a textbook, atlas, methodological developments, tables, diagrams, on natural preparations, computer training and monitoring programs in the electronic reading room of the department and the university, using methodological publications of the department, under the control and consultation of the teacher, study the structure of the small bones of the facial skull and cranial cavities (orbit, bony nasal cavity, paranasal sinuses). Using the whole skull and individual preparations, determine the correct anatomical position of the small bones of the facial skull. On the whole skull, determine the relationship of these bones with other bone formations. On the skull and among individual preparations, find the zygomatic bone, os zygomaticum. Determine on it: surfaces – lateral, temporal, orbital; processes – temporal, frontal; openings – zygomaticoorbital, zygomaticofacial, zygomaticotemporal. On skull preparations, find the lacrimal bone, os lacrimale, nasal bone, os nasale, vomer, vomer, inferior turbinate, concha nasalis inferior. On the lacrimal bone, find the lacrimal groove, the fossa of the lacrimal sac, the posterior lacrimal crest; Find the ethmoid groove on the nasal bone; On the opener, identify the upper, lower and leading edges; on the upper edge, examine the wings of the opener. On the inferior turbinate, identify the lacrimal process, maxillary process, and ethmoid process. Determine the location of all the above bones in relation to adjacent bones. Using the main anatomical formations, determine whether each small bone belongs to the right or left half of the skull. With the skull in the normal facial position, find the entrance to the orbit, the supraorbital margin, the infraorbital margin; walls of the orbit - upper, lower lateral, medial; consider which bones of the skull they are formed from and what structures of these bones form each wall; find the anterior and posterior ethmoidal foramina, lacrimal groove, lacrimal sac fossa, superior and inferior orbital fissures, optic canal, supraorbital foramen, infraorbital groove, canal and opening, fossa of the lacrimal gland, determine the contents of the slits, foramina and other anatomical formations of the orbit. Show the communications of the orbit with the cavity of the skull, nose, and pterygopalatine fossa.
The organ of hearing and balance lies in the temporal bone; vessels and nerves pass through its canals. It forms the base of the skull and the lateral wall of the vault. The temporal bone articulates with the lower jaw and is the support of the masticatory apparatus.
The temporal bone develops from 6 ossification points. At the end of the second month, ossification points appear in the scaly part, in the third month - in the tympanic part, and in the fifth - in the pyramid. In the first year of life, all three parts grow together.
Structure
The temporal bone is a paired formation that has an internal and external surface. It has 3 parts located around the external auditory opening ( porus acusticus externus ): above - scaly part ( pars squamosa ), inwards and behind - the rocky part or pyramid ( pars petrosa ), in front and below - the drum part ( pars tympanica).
Scaly part
It has the shape of a plate and is located almost in the sagittal direction. Below, the scaly part is adjacent to the tympanic and petrous parts and is separated from them, respectively, by the tympanic-squamosal fissure ( fissura tympanosquamosa ) and stony-scaly(fissura petrosquamosa).
On outer surface(in its posterior section) the groove of the middle temporal artery runs in a vertical direction ( sulcus arteriae temporalis mediae ) - trace of the junction of the artery of the same name.
Above and anteriorly from the external auditory opening, the zygomatic process extends horizontally ( processus zygomaticus ), which connects at the anterior end with the temporal process of the zygomatic bone, forming the zygomatic arch ( arcus zygomaticus ). On the anterior root of the zygomatic process there is a thickening - the articular tubercle ( tuberculum articulare ), and on the inner surface there is a postarticular tubercle ( tuberculum retroarticulare)
Between the external auditory opening and the root of the zygomatic process is the mandibular fossa ( fossa mandibularis ). It is covered with cartilage and articulates with the articular process of the lower jaw. At the bottom of this hole there is fissura petrosquamosa and fissura petrostympanica (a nerve emerges from it - the chorda tympani), which are separated by the lower process of the roof of the tympanic cavity.
The inner cerebral surface has cerebral elevations, finger-shaped depressions, and grooves for the vessels of the meninges run along it.
The scaly part has 2 edges: wedge-shaped ( margo sphenoidalis) and parietal (margo parietalis ). Accordingly, the scaly part is connected to the greater wing of the sphenoid bone and to the lower edge of the parietal bone.
Pyramid (rocky part)
It contains most of the elements of the hearing organ: the bony part of the external auditory canal, the middle and inner ear. The petrous part consists of two sections: the posterolateral - mastoid process and the anteromedial - pyramid.
Mastoid process ( Processus mastoideus) located posterior to the external auditory canal. Its outer surface is rough due to the attachment of the sternocleidomastoid muscle to it. It often has a mastoid foramen(foramen mastoideum).
The mastoid notch is visible below ( incisura mastoidea ) - the place of attachment of the posterior belly of the digastric muscle. More medially is the groove of the occipital artery ( sulcus arteria occipitalis).
On the inner surface of the brain there is a wide groove of the sigmoid sinus ( sulcus sinus sigmoidei ), at which the mastoid foramen opens ( foramen mastoideum).
Inside the mastoid process (on the cut) there are cells of different size and shape ( cellula mastoidei ). The largest of them is the mastoid cave ( antrum mastoidei ), communicating with the middle ear cavity.
The mastoid process is separated from the tympanic part by the tympanomastoid fissure ( fissura tympanomastoidea ), where the auricular branch of the vagus nerve passes ( ramus auricularis n. vagus).
Pyramidhas 3 surfaces: front, back and bottom; and, accordingly, 3 edges: top, back and front.
Front surface ( facies anterior) facing the cranial cavity. In its middle there is an arched elevation ( eminentia arcuata ), formed by the underlying semicircular canal of the labyrinth of the inner ear. Between fissura petrosquamosa and eminentia arcuata The roof of the tympanic cavity is located ( tegmentum tympani ), under which is the tympanic cavity. Near the apex of the pyramid there is a trigeminal impression ( impressio trigemeni ) - place of contact of the node trigeminal nerve.(this is a collection of nerve cells; 3 branches extend from it - n. ophthalmicus, n. maxillarisAndn. mandibularis)
The grooves of the greater and lesser petrosal sinuses extend from the apex of the pyramid ( sulcus nervi petrosi majoris et minoris ), which end in clefts of the same name ( hiatus canalis nervi petrosi majoris et minoris ). The corresponding nerves exit through these clefts. Along the upper edge of the pyramid there is a groove of the superior petrosal sinus ( sulcus sinus petrosi superior)
The back surface of the pyramid ( facies posterior) faces the cranial cavity and passes into the mastoid process. Almost in the middle of this surface is the internal auditory opening ( porus acusticus internus ), passing into the internal auditory canal ( meatus acusticus internus ). It contains the front ( VII), intermediate(XIII ), vestibulocochlear nerves ( VIII ); artery and vein of the labyrinth.
Lateral porus acusticus internus there is a subarc fossa ( fossa subarcuata ) - it includes a process of the dura mater. Even more lateral is the external aperture of the vestibule aqueduct ( apertura externa aquaeductus vestibuli ) - through it the endolymphotic duct leaves the ear cavity.
Bottom surface ( facies inferior) lies on the lower surface of the base of the skull. It contains a round or oval-shaped jugular fossa ( fossa jugularis ) - place of contact of the upper bulb of the inner jugular vein. At the bottom of this hole there is a small groove (in it lies ramus auricularis n. vagus ), which leads into the opening of the mastoid tubule ( canaliculus mastoideus).
Anterior to the jugular fossa there is a rounded opening leading to the carotid canal ( canalis caroticus).
Between the jugular fossa and the external opening of the carotid canal there is a stony dimple ( fossula petrosa ) - place of contact of the glossopharyngeal nerve ( IX ). And in the depths of this dimple there is a hole leading into the tympanic canaliculus, where the inferior tympanic artery and tympanic nerve pass (or Jacobson's nerve - mixed (sensitive and autonomic), preganglionic, parasympathetic, coming from nucl. salivatoriusinferiorand central processes of the lower node, i.e. under for. jugulare).
Lateral from fossa jugularis there is a styloid process ( processus styloideus ), from which muscles and ligaments begin. Behind it lies the stylomastoid foramen ( foramen stylomastoideus ), which is the outlet of the facial canal.
Upper edge pyramids- sulcus sinus petrosi superior.
Rear edge pyramids- sulcus sinus petrosi inferior, near which or on which the external aperture of the cochlear tubule lies (apertura externa canaliculi cochleae)
Anterior edge of pyramid - fissura petrosquamosa , on which the opening of the muscular-tubal canal is located lateral to the internal opening of the carotid canal.
Drum part
This is the smallest section of the temporal bone, which forms the anterior, inferior and part of the posterior wall meatus acusticus externus and limits porus acusticus externus . The tympanic cavity is covered with a mucous membrane and contains 3 auditory ossicles: the malleus, the incus and the stapes.
Temporal bone apertures:
1) Apertura externa aquaeductus vestibuli
2) Apertura externa canaliculi cochlea
3) Apertura superior canaliculi tympani - corresponds hiatus canalis nervi petrosi minoris.
4) Apertura inferior canaliculi tympani - lies at the bottom fossula petrosa.
Temporal bone canals
1) Carotid canal (Canalis caroticus ) - begins on the lower surface of the pyramid with an external hole, then, bending almost at a right angle, opens at the top of the pyramid with an internal hole. The internal carotid artery passes through this canal.
2) Carotid tympanic tubules ( Canaliculi caroticotympanici ) - pass through the wall of the carotid canal near its external opening and open into the tympanic cavity. The carotid-tympanic nerves and arteries pass through here.
3) Facial canal (Canalis (nervi) facialis ) - begins at the bottom of the internal auditory canal, goes forward and laterally to the level of the cleft of the canal of the greater petrosal nerve. Here the channel forms the first bend - the elbow ( geniculum canalis facialis ). Next, the canal goes laterally and backward, follows the axis of the stony part and at the level eminentia pyramidalis forms the second limb of the facial canal. And opens in foramen stylomastoideum . The facial nerve passes through this canal ( VII pair of cranial nerves)
4) Drum string channel ( Canaliculus chorda tympani ) - is a branch from the facial canal and begins slightly higher foramen stylomastoideum . It enters the tympanic cavity and ends in fissura petrotympanica . A branch of the facial nerve, the chorda tympani, passes through this canal.
5) Tympanic canaliculus ( Canaliculus tympanicus ) - starts in a pertura inferior canaliculi tympani , enters the tympanic cavity, passes along its medial wall in the groove of the promontory ( sulcus promontorii ), follows to the top wall and opens into a pertura superior canaliculi tympani . This canal contains the lesser petrosal nerve and a branch of the glossopharyngeal nerve - Jacobson's nerve.
6) Musculo-tubal canal (with analis muculotubarius ) - the external opening of the canal is located in the notch between the scaly and petrous parts and runs almost along the axis of the pyramid. A horizontally located septum divides the canal into two semi-canaliculi: semicanalis musculi tensoris tympani (upper and smaller, it contains the muscle that strains the tympanic membrane) and semicanalis tubae auditivae (lower and larger, the Eustachian tube passes through it, which connects the tympanic cavity with the pharyngeal cavity)
7) Mastoid tubule ( Canaliculus mastoideus ) - starts at the bottom fossa jugularis , crosses the lower part of the facial canal and opens into fissura tympanomastoideus . The canal contains the auricular branch of the vagus nerve ( X pair of cranial nerves).
Project Correspondent EstheticLife"
Serova Ksenia
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Home > Abstract >Medicine, health
Ministry of the Republic of Kazakhstan
Karaganda State Medical University
SRSP
The structure of the temporal and sphenoid bones. Canals of the temporal bone.
Completed by: student Gabdolla I.K.
Teacher: Harutyunyan M.G.
Karaganda - 2011
Temporal bone (os temporale) steam room, part of the base and side wall of the skull between the sphenoid bone in front and the occipital bone in the back. It houses the organs of hearing and balance. The temporal bone is divided into pyramid, tympanic and squamosal parts.
Pyramid, or rocky part(pars petrosa), has a triangular shape, located obliquely in the horizontal plane. The apex of the pyramid is directed forward and medially, and the base is directed backward and laterally. At the top of the pyramid is the internal opening of the carotid canal (canalis caroticus). Nearby and to the lateral side is the muscular-tubal canal (canalis musculotubarius), which is divided by a septum into two semi-canals: the semi-canal of the auditory tube (semicanalis tubae auditivae) and the semi-canal of the tensor tympani muscle (semicanalis musculi tensoris tympani).
The pyramid has three surfaces: front, back and bottom. Front surface The pyramid faces up and forward. Near the apex on this surface there is a small trigeminal impression (impressio trigemini). Two openings are visible lateral to this depression. The larger of them is called the cleft (hole) of the canal of the greater petrosal nerve (hiatus canalis nervi petrosi majoris), from which a narrow groove of the same name runs forward and medially. Anterior and lateral is the cleft of the lesser petrosal nerve (hiatus canalis nervi petrosi minoris), which passes into the groove of this nerve. On the front surface of the pyramid there is a flattened section - the roof of the tympanic cavity (tegmen thympani), which is its upper wall. Along the upper edge of the pyramid there is a groove of the superior petrosal sinus (sulcus sinus petrosi superioris).
Back surface of the pyramid facing posteriorly and medially. In the middle of this surface is the internal auditory opening (porus acusticus internus). It leads into the internal auditory canal (medtus acusticus internus). Lateral and slightly above this opening is the subarc fossa (fossa subarcuata), below and lateral to which there is a little noticeable external aperture (hole) of the vestibular aqueduct (apertura externa aqueductus vestibuli). A groove of the inferior petrosal sinus (sulcus sinus petrosi inferioris) runs along the posterior edge of the pyramid. At the lateral end of this groove, adjacent to the jugular fossa, there is a depression, at the bottom of which the external aperture of the cochlear canaliculus (apertura externa canaliculi cochleae) opens.
Bottom surface of the pyramid has a complex terrain. Near the base of the pyramid there is a deep jugular fossa (fossa jugularis). Anterior to it there is a rounded external opening of the carotid canal, inside of which, in its wall, there are 2-3 openings of the carotid-tympanic tubules connecting the carotid canal with the tympanic cavity. On the ridge between the jugular fossa and the external opening of the carotid canal there is a small lobe (fossula petrosa). Lateral to the jugular fossa, a thin and long styloid process (processus styloideus) is directed downward. Behind the process there is a stylomastoid foramen (foramen stylomastoideum), and behind this opening a wide, easily palpable mastoid process (processus mastoideus) is directed downward.
In the thickness of the mastoid process there are air-filled cells. The largest cell, the mastoid cave (Antrum mastoideum), communicates with the tympanic cavity. Medially, the mastoid process is limited by the deep mastoid notch (incisure mastoidea). Medial to this notch is the groove of the occipital artery (sulcus arteriae occipitalis). At the base of the mastoid process there is sometimes a mastoid foramen (foramen mastoideum).
Drum part(pars tympanica) is formed by a curved narrow bone plate, which in front, below and behind limits the external auditory opening (porus acusticus externus), leading into the external auditory canal (meatus acusticus externus). Between the tympanic part and the mastoid process there is a narrow tympanomastoid fissure (fissure tympanomastoidea). In front of the external auditory opening is the tympanic-squamous fissure (fissure tympanosquamosa). A narrow bone plate protrudes into this gap from the inside - the edge of the roof of the tympanic cavity. As a result, the tympanic-squamous fissure is divided into the anterior stony-squamous fissure (fissura petrosquamosa) and the petrotympanic fissure (fissura petrotympanica, Glaser's fissure), through which a branch of the facial nerve - the chorda tympani - emerges from the tympanic cavity.
Scaly part(pars squamosa) is a convex plate outward, having a beveled free upper edge for connection with the parietal bone and the greater wing of the sphenoid bone. The outer temporal surface of the scales is smooth. On the inner cerebral surface of the scales there are cerebral elevations, finger-like impressions and arterial grooves. From the scales, above and anterior to the external auditory canal, the zygomatic process (processus zygomaticus) begins. Connecting with the temporal process of the zygomatic bone, it forms the zygomatic arch. Behind the zygomatic process, at its base, is the mandibular fossa (fossa mandibularis) for articulation with the condylar process of the mandible to form the temporomandibular joint.
Canals of the temporal bone.
Sleepy channel canalis cardticus) begins on the lower surface of the pyramid with the external carotid foramen, goes upward, bends almost at a right angle, then goes medially and forward. The canal ends with the internal carotid foramen at the top of the pyramid of the temporal bone. The internal carotid artery and the nerves of the carotid plexus pass through this canal into the cranial cavity.
Carotid-tympanic tubules(canaliculi caroticotympanic!), numbering 2-3, depart from the carotid canal and go to the tympanic cavity. These tubules contain arteries and nerves of the same name.
Musculo-tubal canal(canalis musculotubarius) begins at the top of the pyramid of the temporal bone, goes back and laterally and opens into the tympanic cavity. A horizontal partition divides it into two parts. Above is the hemicanal of the tensor tympani muscle (semicanalis musculi tensoris tympani), containing the muscle of the same name. Below is a half-channel auditory tube(semicanalis tubae auditivae).
Facial canal(canalis facialis) begins in the internal auditory canal. It first runs transverse to the long axis of the pyramid to the level of the cleft of the greater petrosal nerve canal. Having reached the cleft, the canal forms a knee, then is directed at a right angle back and laterally. Having passed along the medial wall of the tympanic cavity, the canal turns vertically downwards and ends with the stylomastoid foramen. The facial nerve passes through this canal.
Drum string channel(canaliculus chordae tympani) comes from the wall of the facial canal in its final section and opens into the tympanic cavity. The nerve, the chorda tympani, passes through this canal.
Drum tubule(canaliculus tympanicus) begins at the bottom of the stony dimple, goes up, pierces the wall of the tympanic cavity. The canaliculus then passes along its medial wall and ends in the area of the cleft of the canal of the lesser petrosal nerve. The tympanic nerve passes through this canaliculus.
Mastoid tubule(canaliculus mastoideus) begins in the jugular fossa and ends in the tympanomastoid fissure. The auricular branch of the vagus nerve passes through this canaliculus.
Several channels of the temporal bone pass through the pyramid for cranial nerves and blood vessels.
Sleepy channel(canalis caroticus) begins on the lower surface of the pyramid with the external carotid foramen, goes upward, bends almost at a right angle, then goes medially and forward. The canal ends with the internal carotid foramen at the top of the pyramid of the temporal bone. The internal carotid artery and the nerves of the carotid plexus pass through this canal into the cranial cavity.
Carotid-tympanic tubules(canaliculi caroticotympanici), numbering 2-3, depart from the carotid canal and go to the tympanic cavity. These tubules contain arteries and nerves of the same name.
Musculo-tubal canal(canalis musculotubularis) begins at the top of the pyramid of the temporal bone, goes back and laterally and opens into the tympanic cavity. A horizontal partition divides it into two parts. Above is the hemicanal of the tensor tympani muscle (semicanalis musculi tensoris tympani), containing the muscle of the same name. Below is the semicanal of the auditory tube (semicanalis tubae auditivae).
Facial canal(canalis facialis) begins in the internal auditory canal. It first runs transverse to the long axis of the pyramid to the level of the cleft of the canal of the greater petrosal nerve. Having reached the cleft, the canal forms a knee, then is directed at a right angle back and laterally. Having passed along the medial wall of the tympanic cavity, the canal turns vertically downwards and ends with the stylomastoid foramen. The facial nerve passes through this canal.
Drum string channel(canaliculus chordae tympani) comes from the wall of the facial canal in its final section and opens into the tympanic cavity. The nerve, the chorda tympani, passes through this canal.
Tympanic canaliculus(canaliculus tympanicus) begins at the bottom of the stony dimple, goes up, pierces the wall of the tympanic cavity. The canaliculus then passes along its medial wall and ends in the area of the cleft of the canal of the lesser petrosal nerve. The tympanic nerve passes through this canaliculus.
Mastoid tubule(canaliculus mastoideus) begins in the jugular fossa and ends in the tympanomastoid fissure. The auricular branch of the vagus nerve passes through this canaliculus.
Sphenoid bone (os sphenoidale) occupies a central position at the base of the skull. It participates in the formation of the base of the skull, its lateral sections and a number of cavities and pits. The sphenoid bone consists of a body, pterygoid processes, greater and lesser wings.
Body of the sphenoid bone(corpus sphenoidale) has an irregular shape and six surfaces: upper, lower, posterior, fused (in an adult) with the basilar part of the occipital bone, anterior and two lateral surfaces. On the upper surface of the body there is a depression - the sella turcica (sella turcica) with a deep pituitary fossa (fossa hypophysialis). At the back of the sella turcica there is a dorsum sellae (dorsum sellae), and at the front there is a tuberculum sellae (tuberculum sellae). On each side of the body of the bone, a carotid groove (sulcus caroticus) is visible - a trace of the attachment of the internal carotid artery. On the anterior surface of the body of the sphenoid bone there is a wedge-shaped crest (crista sphenoidalis). On the sides of the crest there are irregularly shaped wedge-shaped shells (conchae sphenoidales), limiting the apertures of the sphenoid sinus. The sphenoid sinus (sinus sphenoidalis) is an air-filled cavity communicating with the nasal cavity.
The lateral surfaces of the body of the sphenoid bone directly pass into paired small and large wings.
Small wing(ala minor) is a laterally directed flattened bone plate, at the base of which is the optic canal (canalis opticus), leading to the orbit. The posterior free edge serves as the boundary between the anterior and posterior cranial fossae. The anterior margin connects with the orbital part of the frontal bone and the cribriform plate of the ethmoid bone. Between the small wing at the top and the upper edge big wing there is an elongated opening - the superior orbital fissure (fissura orbitalis superior), connecting the cranial cavity with the orbit.
Big wing(ala major) starts from the lateral surface of the body of the sphenoid bone with a wide base and, like the lesser wing, is directed to the lateral side. It has four surfaces: medullary, orbital, temporal and maxillary. The concave surface of the brain faces the cranial cavity. There are three holes on it through which they pass blood vessels and nerves. A round opening (foramen rotundum), located closer to the base of the greater wing, leads into the pterygopalatine fossa. At the level of the middle of the wing there is an oval foramen (foramen ovale), which opens at the base of the skull, and behind it there is a small spinous foramen (foramen spinosum). The orbital surface (facies orbitalis) is smooth and participates in the formation of the lateral wall of the orbit. On the temporal surface (facies temporalis) there is an infratemporal crest (crista infratemporalis), oriented in the anteroposterior direction and delimiting the temporal fossa from the infratemporal fossa on the lateral surface of the skull.
The maxillary surface (facies maxillaris) faces forward - into the pterygopalatine fossa.
Pterygoid process(processus pterygoideus) paired, extends downwards from the body of the sphenoid bone. The process consists of medial and lateral plates (lamina medialis et lamina lateralis). At the back between the plates there is a pterygoid fossa (fossa pterygoidea). At the base of the pterygoid process, a narrow pterygoid (vidian) canal (canalis pterygoideus) runs from back to front, connecting the pterygopalatine fossa with the region of the foramen lacerum on the whole skull.
Occipital bone (os occipitale) is located in the posterior lower part of the cerebral part of the skull. This bone contains a basilar part, two lateral parts and an occipital scale, which surround the large (occipital) foramen (foramen magnum).
Basilar part(pars basilaris) is located in front of the large (occipital) foramen. In front, it connects with the body of the sphenoid bone, together with which it forms a platform - the slope (clivus). On the lower surface of the basilar part there is an elevation - the pharyngeal tubercle (tuberculum pharyngeum), and along the lateral edge there is groove of the inferior petrosal sinus(sulcus sinus petrosi inferioris).
Lateral part(pars lateralis) steam room, from behind it passes into the scales of the occipital bone. Below on each lateral part there is an ellipsoidal elevation - the occipital condyle (condylus occipitalis), at the base of which is the canal of the hypoglossal nerve (canalis nervi hypoglossi). Behind the condyle there is a condylar fossa (fossa condylaris), and at its bottom there is an opening of the condylar canal (canalis condylaris). On the side of the occipital condyle is the jugular notch (incisura jugularis), which, together with the jugular notch of the pyramid of the temporal bone, forms the jugular foramen. Next to the jugular notch on the brain surface there is a groove for the sigmoid sinus (sulcus sinus sigmoidei).
Occipital scales(squama occipitalis) - a wide, convex plate outward, the edges of which are highly jagged. On the whole skull they connect to the parietal and temporal bones. In the center of the outer surface of the scales, the external occipital protuberance (protuberantia occipitalis externa) is visible, from which a weakly defined upper line (linea nuchae superior) extends in both directions. The external occipital crest (crista occipitalis externa) runs down from the protrusion to the foramen magnum (occipital foramen). From its middle, a lower line (hinea nuchae inferior) goes to the right and left. The highest line (linea nuchae suprema) is sometimes visible above the external occipital protrusion.
On the inner side of the occipital scales there is a cruciform eminence (eminentia cruciformis), dividing the brain surface of the scales into 4 pits. The center of the cruciform eminence forms the internal occipital protuberance (protuberantia occipitalis interna). To the right and left of this protrusion there is a groove of the transverse sinus (sulcus sinus transversus). Up from the protrusion there is a groove of the superior sagittal sinus (sulcus sinus sagittalis superioris), and down, to the large (occipital) foramen, there is the internal occipital crest (crista occipitalis interna).
Bones (Fig. 4, 2) lies a small main wedge-shaped bone(basisphenoideum). It is completely covered by a wide main temporal bone... shock-absorbing device - forks), structure wing skeleton (including...
Os temporale - steam room, complex in shape and structure. It participates in the formation of the base of the skull and complements the lateral walls of the roof of the skull. The organs of hearing and balance are located in the temporal bone; nerves and blood vessels pass through its canals. On its outer surface there is the external auditory opening, porus acusticus extemus, around which there are three parts of the temporal bone: the squamous bone, pars squamosa; stony, pars petrosa and drum, pars tympanica.
The scales and tympanic part develop on the basis of connective tissue, and the stony part develops on the basis of cartilage.
Scaly part, pars squamosa, has the shape of a thin plate located in sagittal plane. A squamoid suture connects its free edge with the lower edge of the parietal bone and the greater wing. The lower part of the scales is adjacent to the stony and tympanic part and is delimited from it by a stony-scaly fissure, fissura petrosquamosa, and from the tympanic part by a tympanic-squamous fissure, fissura thympanosquamosa. In the posterior part of the scales there is a groove of the middle temporal artery, sul. A. temporalis mediae. In the posterior-inferior section, the temporal line is distinguished. Above the scales and slightly forward, the zygomatic process, processus zygomaticus, extends, which originates with a wide root and then tapers. It fuses with the process of the zygomatic bone and forms the zygomatic arch, arcus zygomaticus. On the lower surface of the root there is an articular mandibular fossa, fossa mandibularis. In front, the articular fossa is limited by the articular tubercle, tuberculum articulare, and behind by the extraglobal tubercle, tuberculum retroarticulare. The inner medullary surface of the squama contains finger-like indentations, cerebral protrusions and grooves from the middle meningeal artery, a. meningea media, in case of damage to the scales, aneurysms of this artery may occur; this should be taken into account in clinical (neurosurgical) practice.
Rocky part, pars petrosa, has the shape of a triangular pyramid, the top of which is directed inward and forward, and the base is directed back and sideways. In the stony part, the following surfaces are distinguished: anterior, fades anterior partis petrosae, posterior, fades posterior partis petrosae, and lower, fades inferior partis petrosae, as well as the upper, posterior and anterior corner.
The front surface of the pyramid faces the cranial cavity. Almost in the middle of the anterior surface there is an arcuate elevation, eminentia arcuata, which coincides with the anterior semicircular canal of the labyrinth.
The roof of the tympanic cavity is adjacent to the elevation. On the anterior surface of the pyramid, at its apex, there is a trigeminal squeeze, impressio trigeminalis, for the trigeminal ganglion. To the side of it is the formation of the canal of the greater petrosal nerve, hiatus canalis n. petrosi majoris, from which the medial groove of the greater petrosal nerve, sul. n. petrosi majoris. Slightly in front and to the side is the upper course of the lesser petrosal nerve, hiatus canalis n. petrosi minoris, from which the groove of the lesser petrosal nerve, sul. n. petrosi minoris. The nerves of the same name exit through these holes.
On the back surface of the stony part, almost in the middle, there is an internal auditory opening, porus acusticus internus, leading to the internal auditory canal, meatus acusticus internus. At the upper edge of the stony part, in the area between the internal auditory opening and the external opening of the aqueduct of the vestibule, there is a subarc fossa, fossa subarcuata. And at the lower edge there is the opening of the cochlea's aqueduct, apertura externa agueductus cochleae. Above and to the side of this opening is the external opening of the vestibular aqueduct, apertura externa agueductus vestibuli, through which the endolymphatic duct, ductus endolymphaticus, passes.
On the lower surface of the stony part there is an oval-shaped jugular fossa, fossa jugularis, at the bottom of which there is a groove leading to the opening of the mastoid canaliculus. The posterior edge of the jugular fossa is limited by the jugular notch, incisura jugularis. Anterior to the jugular fossa is the external opening of the carotid canal, apertura externa canalis carotid, which leads into the carotid canal, canalis caroticus, which opens at the apex of the petrous part with an internal opening, apertura interna canalis carotid. At the external opening on the posterior wall of the carotid artery canal there are openings of the carotid-tympanic tubules, canaliculi caroticotympanici, opening into the tympanic cavity, through which vessels and nerves pass. Between the jugular fossa and the external opening of the carotid canal there is a stony dimple, fossula petrosa, in the depth of which is the lower opening of the tympanic tubule, apertura inferior canaliculi tympanici (BNA). On the side of the jugular fossa there is a downward styloid process, processus styloideus, which is the site of attachment of the “anatomical bouquet” (mm. styloglossus, stylohyoideus, stylophmyngeus) and the ligament ligg. stylohyoideum et stylomandibular. Behind the root of the process there is a stylomastoid opening, foramen stylomastoideus. In front and outside the styloid process there is a bony protrusion of the tympanic part - the vagina of the styloid process, vagina processus styloidei.
The upper edge of the stony part separates its anterior surface from the posterior one. Along this edge runs the upper stony groove, sul. sinus petrosi superioris. The posterior edge of the petrous portion separates the posterior surface from the inferior surface. Along this edge runs the lower stony groove, sul. sinus petrosi inferioris. The anterior edge of the stony part separates its anterior surface from the lower one. On it, on the side of the internal opening of the carotid canal, there is an opening of the muscular-tubal canal, canalis musculotubarius, which connects the tympanic cavity with the nasal part of the pharynx.
Below, the base of the stony part is elongated into the mastoid process, processus mastoideus, the outer surface on it is rough from the muscle attached to it. At the opening of the mastoid process, cells, cellulae mastoidei, are visible, lined with mucous membrane. The largest cell, called the mastoid cave, antrum mastoideum, communicates with the cavity of the middle ear. In the case of inflammation of the middle ear (otitis), the infection can penetrate into the cells and lead to their purulent inflammation(mastoiditis), the treatment of which requires surgery.
Externally, two grooves run from the mastoid process: the medial one - for the occipital artery, sul. a. occipitalis, and slightly to the side - the mastoid notch, incisura mastoidea. The mastoid process is separated from the tympanic part by the tympanomastoid fissure, fissura tympanomastoidea, which is the site of passage of the auricular branch of the vagus nerve.
In the area between the occipital bone and the mastoid process there is a mastoid foramen, the foramen mastoideum is the widest. Basically, the mastoid foramen is located in the occipital-mastoid suture (C. Libersa, 1934). On the outer surface of the mastoid process, the mastoid triangle (Shipo) is conventionally distinguished, which is the site of trephination (anthrotomy) for inflammatory conditions of the middle ear (cells and cave). On the inner surface of the mastoid process there is a groove of the sigmoid sinus, sul. sinus sigmoidei. Along with the S-shaped form, there are hook-shaped, sickle-shaped, straight and arched forms (G.D. Burdei, 1951, 1955). In the middle section of the groove of the sigmoid sinus, the mastoid opening, foramen mastoideum, opens, through which the mastoid emissary vein passes, connecting the sigmoid sinus with the suboccipital venous plexus.
Drum part, pars tympanica, located around the external auditory canal, meatus acusticus extemus. It limits below and behind the external auditory opening, porus acusticus extemus, and the tympanic cavity, cavitas tympanica, and with its free edge it fuses with the scales and the mastoid process.
It is separated from the scales by a tympanic-squamous fissure, fissura tympanosquamosa, into which a process of the roof of the tympanic cavity is inserted. It divides it into two fissures: the stony-squamous, fissura petrosquamosa, and the stony-tympanic, fissura petrotympanica (Glaseri), through which a branch of the intermediate nerve emerges from the tympanic cavity - the chorda tympani. Above the external auditory opening is the suprachnoid spine, spina suprameatica. The cartilaginous part of the auditory canal is attached to the free rough edge of the tympanic part, which limits the external auditory opening.
Ossification. A baby's temporal bone is made up of three parts. The first ossification points appear in the scales at 8 weeks of intrauterine development, and at 3 months - in the tympanic part. At the 5th month, five points of ossification appear in the cartilaginous base of the petrous part. In a newborn, parts of the temporal bone are separated by gaps filled with connective tissue, which grow together during the first year of life.
Canals and cavities of the temporal bone
There are seven canals of the temporal bone: 1. Facial nerve canal, canalis n. facialis;2. Musculo-tubal canal, canalis musculotubarius;
3. Carotid canal, canalis caroticus
4. Carotid-tympanic tubules, canaliculi caroticotympanic;
5. Canaliculus chorde tympanv,
6. Tympanic tubule, canaliculus tympanicus;
7. Mastoid tubule, canaliculus mastoideus.
Facial nerve canal, canalis n. facialis - originates at the bottom of the auditory canal, goes at a right angle to the axis of the petrous part and goes to the formation of the large petrosal nerve, hiatus canalis n. petrosi majoris, where it turns and forms the elbow of the facial canal, geniculum canalis facialis. The ganglion of the geniculate facial nerve is located here, from which the greater petrosal nerve arises. After which it passes along the posterior wall of the tympanic cavity, forming protrusions of the facial canal, prominentia canalis facialis, then the canal goes vertically downwards, where it opens with a stylomastoid opening, foramen stylomastoideus. The canal contains the facial and intermediate nerves (VII pair), the superficial petrosal branch from the middle meningeal artery and the stylomastoid artery and vein.
Musculo-tubal canal, canalis musculotubarius - originates in the notch between the petrous and squamosal parts of the temporal bone and runs along the axis of the petrous part. The bony septum divides it into two semi-canals: the upper - the semi-canal of the muscle that stretches the tympanic membrane, semicanalis musculi tensoris tympani, and the lower - the semi-canal of the auditory tube, semicanalis tube auditoriae (LNA). The upper one contains a muscle that stretches the eardrum, the lower one connects the tympanic cavity with the pharyngeal cavity.
Sleepy channel, canalis caroticus - originates on the lower surface of the stony part with the external carotid foramen, apertura externa canalis carotici. The canal goes upward, passes in front of the tympanic cavity, forming a bend, and then goes forward and medially, opening with the internal carotid foramen, apertura interna canalis carotid, at the apex of the petrous part. The canal contains the internal carotid artery, the veins that accompany it, and a nice nerve plexus.
Carotid-tympanic tubules, canaliculi caroticotympanici - small tubules that branch from the carotid canal and lead into the tympanic cavity. The carotid-tympanic nerves pass through here.
Drum string Canadian, canaliculus chorde tympani - originates on the wall of the facial canal above the stylomastoid foramen, goes forward and upward, enters the tympanic cavity and opens on its posterior wall. A branch of the intermediate nerve passes through the canal - the chorda tympani, which exits the tympanic cavity through the petrotympanic fissure.
Tympanic canaliculus, canaliculus tympanicus - originates in the stony fossa, fossula petrosa, then through the lower wall enters the tympanic cavity, passes along its medial wall, and rises upward, where it opens with the gap of the lesser petrosal nerve, hiatus canalis n. petrosi minoris. The tympanic nerve passes through the canal, which, at the exit from the tympanic cavity, is called the lesser petrosal nerve (branch of the IX pair).
Mastoid tubule, canaliculus mastoideus - originates in the depths of the jugular fossa, crosses the facial canal in its lower part and opens in the tympanomastoid fissure. The auricular branch of the vagus nerve passes through the canal.
Tympanic cavity, cavitas tympania, discussed in the “Sense Organs” section.