Carotid canal of the temporal bone in Latin. Anatomy of the human temporal bone

1. Sleepy channel,canalis caroticus .

The beginning of the canal is the external opening of the carotid canal on the lower surface of the pyramid.

The end of the canal is the internal opening of the carotid canal at the apex of the pyramid.

Contents: internal carotid artery.

2. Channelfacialnerve, canalis nervi facialis .

The beginning of the canal is at the bottom of the internal auditory canal.

The end of the canal is the stylomastoid opening on the lower surface of the pyramid.

Contents – facial nerve.

3. Musculo-tubal canal,canalis musculotubarius .

a) hemicanal of the tensor muscle eardrum, semicanalis muscles tensoris tympani ,

b) half-channel auditory tube, semicanalis tubae auditivae .

The beginning of the canal is the opening of the myotubal canal at the anterior edge of the pyramid.

The end of the canal is in the tympanic cavity.

Contents: tensor tympani muscle,

Eustachian tube.

4. Drum string channel,canaliculus chordae tympani .

The beginning of the tubule is in the facial canal, above the stylomastoid foramen.

The end of the tubule is the petrotympanic fissure.

Contents: chorda tympani, branch of the facial nerve.

5. Tympanic canaliculus,canaliculus tympanicus .

The beginning of the tubule is a stony dimple on the lower surface of the pyramid.

The end of the tubule is the cleft of the canal of the lesser petrosal nerve on the anterior surface of the pyramid.

Contents: tympanic nerve, branch of the glossopharyngeal nerve.

6. Mastoid tubule,canaliculus mastoideus .

The beginning of the canaliculus is the jugular fossa (mastoid foramen) on the lower surface of the pyramid.

The end of the tubule is the tympanomastoid fissure.

Contents: auricular branch of the vagus nerve.

7. Carotid-tympanic tubules,canaliculi caroticotympanici .

The beginning of the tubules is on the wall of the carotid canal, near its external aperture.

The end of the tubules is the tympanic cavity.

Contents: carotid-tympanic arteries, branches of the internal carotid artery;

Carotid-tympanic nerves, branches of the internal carotid plexus.

BONES OF THE FACIAL SKULL

Paired: - upper jaw, maxilla;

palatine bone, os palatinum;

Cheekbone, os zygomaticum;

nasal bone, os nasale;

lacrimal bone, os lacrimale;

inferior nasal concha, concha nasalis inferior.

Unpaired: - lower jaw, mandibula;

opener, vomer;

Hyoid bone, os hyoideum.

Upper jaw, maxilla

Parts: - body,

frontal process,

Zygomatic process,

Alveolar ridge,

Palatine process.

1. Body,corpus , contains the maxillary (maxillary) sinus, sinus maxillaris:

1) front surface, facies anterior:

Infraorbital margin, margo infraorbitalis;

infraorbital foramen, foramen infraorbitale;

canine fossa, fossa canina;

nasal notch, incisura nasalis;

Anterior nasal spine, spina nasalis anterior;

2) orbital surface, facies orbitalis:

Infraorbital groove, sulcus infraorbitalis;

infraorbital canal, canalis infraorbitalis;

3) infratemporal surface, facies infratemporalis:

Tubercle of the maxilla, tuber maxillae;

alveolar openings, foramina alveolaria;

alveolar canals, canales alveolares;

Greater palatine sulcus sulcus palatinus major;

4) nasal surface, facies nasalis:

maxillary cleft, hiatus maxillaris;

tear trough, sulcus lacrimalis;

shell comb, crista conchalis.

2. Frontal shoot, processus frontalis:

Anterior lacrimal ridge crista lacrimalis anterior;

lattice comb, crista ethmoidalis.

3. Skulova shoot, processus zygomaticus .

4. Alveolar shoot, processus alveolaris :

alveolar arch, arcus alveolaris;

dental alveoli, alveoli dentales;

interalveolar septa, septa interalveolaria;

Alveolar eminences, yuga alveolaria.

5. Palatine shoot, processus palatinus :

nasal ridge, crista nasalis;

Palatine grooves, sulci palatini;

Incisive canal, canalis incisivus.

Carotid canal: short and curved, has an external opening on the lower surface of the pyramid and an internal opening that opens into the cranial cavity (middle cranial fossa), passes the internal carotid artery with its petrosal flexure and the internal carotid sympathetic nerve.

Musculo-tubal canal:

· has a common wall with the carotid canal;

· consists of two semicircular canals: the superior one for the tensor tympani muscle and the inferior one for the auditory tube.

Both semicircular canals open in tympanic cavity, and the auditory tube with the opposite end also goes into the nasopharynx.

The facial canal has an inlet at the bottom of the internal auditory canal, and the exit from the canal is the stylomastoid foramen. There is a complex, loop-like passage in the channel, and inside the rocky part and closer to the base of the pyramid a bend in the form of an elbow is formed.

The canal contains the facial nerve with the genu ganglion; inside the pyramid it has openings for the branches of the nerve to exit into the tympanic cavity.

Drum string channel:

· departs from the facial canal and opens into the tympanic cavity;

· a branch of the facial nerve passes through the canaliculus - the chorda tympani, which leaves the skull through the petrotympanic fissure.

Tympanic canaliculus:

· the lower hole lies in a stony dimple;

· the canal passes through the tympanic cavity and the septum of the muscular-tubal canal;

· the superior opening opens into the cleft of the lesser petrosal nerve on the anterior surface of the pyramid;

· in the tubule, the tympanic nerve, a branch of the glossopharyngeal nerve (IX pair), passes into the tympanic cavity, and the lesser petrosal nerve exits.

Carotid tympanic tubules (two):

· origin in the wall of the carotid canal near the external carotid foramen;

end in the tympanic cavity;

· contents - carotid-tympanic sympathetic nerves and vessels.

Mastoid tubule:

· the beginning in the jugular fossa, along its course crosses the facial canal, opens into the tympanomastoid fissure;

· contents - auricular branch of the vagus nerve (X pair).

10(II) Sphenoid bone

In the development of bones, the following are important:

· endochondral ossification of 5 pairs of primary nuclei, formed at the 9th week of the fetal period in the body and wings;

· endodesmal ossification of the pterygoid processes and the tips of the greater wings, beginning at 8 weeks;

· fusion of the body, small and large wings, and pterygoid processes occurs at the age of 3-8 years.

The sphenoid sinus appears at the 3rd year of life, its formation ends at 30-40 years.

During development, at the initial stage, a pharyngeal-cranial canal is formed in the body of the bone, through which the anterior rudiment of the pituitary gland passes from the primary oral cavity. After the movement of the rudiment, the canal becomes overgrown, and in case of developmental disorders, a cranial hernia occurs.

The sphenoid bone - pneumatic - consists of a body, small and large wings and pterygoid processes.

Body - contains the pneumatic sinus inside and has six surfaces:

· upper (cerebral);

· lower - with openings of the sphenoid sinus for communication with the nasal cavity;

· anterior, adjacent to the ethmoid bone and forms a sphenoid-ethmoid synchondrosis;

· the posterior one connects to the basilar part of the occipital bone, participating in the formation of the clivus and spheno-occipital synchondrosis;

· lateral: right and left go into the wings.

On the upper surface of the body there is a sella turcica, and in it:

· pituitary fossa - for the pituitary gland - the central neuroendocrine gland;

· tubercle sella - anterior to the fossa;

· back of the saddle with posterior inclined processes - posterior to the fossa;

· carotid grooves: right and left with wedge-shaped tongues, lie on the lateral surfaces of the saddle, intended for the internal carotid artery and internal carotid sympathetic nerve, venous cavernous sinus.

On the front surface of the body:

· wedge-shaped ridge, passing downwards into the keel.

On the lower surface of the body:

· wedge-shaped keel (beak);

· on the sides of the beak and crest there are wedge-shaped shells that limit the wedge-shaped openings leading to the sinus.

The lateral (lateral) surfaces continue into the lesser and greater wings.

Small wings: right and left - lie in front and on the sides of the body. They have:

front edge connecting to frontal bone flat seam;

· the posterior edge is free, facing the middle cranial fossa along with the medially located anterior inclined processes;

· the optic canal under the inclined processes - for the optic nerve (II pair) and the central artery and vein of the retina;

Optic chiasm groove connecting internal holes visual channels.

Large wings: right and left.

· At the base of the wing, closer to the sella turcica, there are three holes sequentially from front to back: round - for the second branch trigeminal nerve(Y pair), oval - for the third branch of the trigeminal nerve, spinous - for the middle meningeal artery.

· The sphenoid spine is located behind and below the opening for the meningeal artery.

· Surfaces of the wings: cerebral - with cerebral projections, digital depressions, arterial grooves, orbital - for the lateral wall of the orbit, maxillary - facing the pterygopalatine fossa, has a round opening, temporal - divided by the infratemporal crest into two parts - temporal and infratemporal.

Between the lesser and greater wings there is the superior orbital fissure, through which pass: the oculomotor (III pair), trochlear (IY pair), abducens (YI pair) cranial nerves and the first branch (ophthalmic, orbital nerve) of the trigeminal nerve (Y pair), as well as the orbital artery and vein.

The right and left pterygoid processes extend from the lower surface of the body and contain:

· medial and lateral plates, fused in front, where the pterygopalatine groove passes;

· between the plates behind and downwards there is a pterygoid fossa, which passes downwards into the pterygoid notch;

· the medial plate is longer and ends with a hook;

· at the base of the pterygoid processes there is a canal of the same name for vessels and nerves.

11(II) Pterygopalatine fossa

It is part of the facial skull, but is located on the border with the outer base of the cranium. The fossa is adjacent to and has connections with the temporal and infratemporal fossa. The upper jaw with its tubercle and posterior surface, the sphenoid bone with its greater wing and pterygoid process, and the pterygoid process participate in its formation. palatine bone- perpendicular plate. The shape of the fossa is a narrow gap limited by the three bones listed above; it borders and communicates with the cranial cavity (middle cranial fossa), the cavities of the nose and mouth, the orbit, the temporal and infratemporal fossa.

The pterygopalatine fossa has the following walls:

· The anterior wall includes the tubercle of the maxilla with the posterior alveolar foramina, through which the superior posterior alveolar vessels and nerves pass from the fossa to supply the maxilla, its alveoli, teeth and gums.

The posterior wall is the maxillary surface of the greater wing and the base of the pterygoid process sphenoid bone with a channel of the same name, which passes into the fossa from the area torn hole autonomic pterygoid nerve and vessels of the same name.

· The medial wall is a perpendicular plate of the palatine bone and a small section of the sphenoid bone adjacent to it; vessels and nerves for the nasal mucosa pass through the sphenopalatine foramen of the wall from the fossa.

The pterygopalatine fossa communicates:

· with the oral cavity through the greater and lesser palatine canals with the vessels and nerves of the same name that supply the hard and soft palate and the palatine tonsils;

· with the nasal cavity through the sphenopalatine foramen with the same vessels and nerves for the mucous membrane of the turbinates and nasal passages;

· with average cranial fossa through the foramen rotundum, through which the maxillary branch of the trigeminal nerve passes;

· with the area of ​​the torn opening through the pterygoid canal, containing the autonomic nerve and vessels of the same name;

· with the orbit through the inferior orbital fissure for the passage of the infraorbital branches of the maxillary vessels and nerves;

· With infratemporal fossa through the pterygomaxillary fissure, where the connection is made by connective tissue and fatty tissue.

The fossa is filled with fiber, part of the pterygoid venous plexus, the terminal sections of the maxillary vessels, the maxillary branch of the Y pair and the parasympathetic pterygopalatine ganglion of the head with postganglionic branches extending from it: orbital, medial and lateral nasal, greater and lesser palatine, inferior posterior nasal. The maxillary branch of the trigeminal nerve, the terminal section of the maxillary artery, and the maxillary vein, which flows into the pterygopalatine plexus, pass through the fossa.

The infraorbital and zygomatic nerves and nodal branches to the pterygopalatine ganglion depart from the maxillary nerve in the fossa. Through the inferior orbital fissure, the infraorbital nerve enters the orbit, where it lies in the infraorbital groove and canal and gives off the superior alveolar nerves (anterior, middle and posterior) to the teeth, gums and alveoli. From the orbit, through the same gap, the vegetative orbital branches enter the fossa and enter the node. From the hard and soft palate, the greater and lesser palatine nerves enter the fossa, using the canals of the same name. From the mucous membrane of the nasal cavity, vegetative posterior nasal branches are directed through the sphenopalatine foramen into the node.

In the pterygopalatine fossa there is the final section of the maxillary artery with the following branches: infraorbital, sphenopalatine and palatine arteries, pharyngeal branches and branches to the auditory tube. The infraorbital artery leaves the fossa through the inferior orbital fissure and supplies the upper jaw, teeth and gums, lower eyelid, lacrimal sac and muscles of the eye, cheek and upper lip, forming anastomoses with the facial artery. The sphenopalatine artery leaves through the homonymous foramen to supply blood to the mucous membrane of the lateral wall and septum of the nose. The parotid veins flow into the pterygoid venous plexus salivary gland, middle meningeal, tympanic, inferior ophthalmic and deep facial.

Loose connective tissue fills the pterygopalatine fossa and serves as a support (soft skeleton) for the vessels and nerves located here. It is associated with the fiber of the temporopterygoid, suprapterygoid, interpterygoid and pterygomaxillary space. Through the pterygomaxillary fissure, fiber penetrates into the infratemporal fossa, and from it into the temporal fossa.

Temporal pit

· superior and posterior borders: temporal line;

· lower: infratemporal crest of the large wings, zygomatic arch;

· anterior: zygomatic bone (posteromedial surface).

The pit is filled with the temporal muscle and fiber, which forms the inter- and subgaleal and deep temporal spaces:

The interaponeurotic space lies above the zygomatic arch between the superficial and deep layers of the temporal fascia;

The subgaleal aponeurotic is located under the temporal aponeurosis, the deep is located under the temporal muscle.

Infratemporal fossa

This is a downward continuation of the temporal fossa.

· upper limit: infratemporal crest and upper edge of the zygomatic process; the ridge serves as the boundary between the temporal and infratemporal fossa;

· lower border: lateral plate of the pterygoid process and the base of the greater wing of the sphenoid bone;

· anterior: orbital margin of the greater wing and anterior margin of the pterygoid process;

lateral: the inner surface of the ascending branches lower jaw;

Posterior: anteroinferior surface of the base of the zygomatic process.

The infratemporal fossa communicates with the temporal and pterygopalatine fossae through the cellular spaces.

12(II) Nasal cavity

In the facial skull, the nasal cavity is located in the middle and has:

bony septum - (from the perpendicular plate of the ethmoid bone and vomer), which divides the nasal cavity into the right and left halves;

the entrance, designated as a pyriform aperture, bounded above by the edges of the nasal bones, on the side by the nasal notches of the upper jaws, below by the anterior nasal spine of the upper jaws;

the exit is the choanae, bounded laterally by the medial plates of the pterygoid processes, from the inside by the vomer, above by the body of the sphenoid bone, below by the horizontal plates of the palatine bones with the posterior nasal spine.

The nasal cavity has upper, lower and paired side walls.

The upper wall consists of:

· the nasal part of the frontal bone, the perforated plate of the ethmoid bone and the body of the sphenoid, which form the superior posterior part of the wall;

· paired nasal bones: right and left, forming the anterior-superior part of the wall.

The bottom wall includes:

· palatine processes of the upper jaws and horizontal plates of the palatine bones - bony palate;

· nasal ridge, which runs along the middle of the wall in the longitudinal direction.

The lateral walls (right and left) consist of:

· nasal surfaces of the body and frontal processes of the upper jaws, lacrimal bones, lattice labyrinth, perpendicular plates of the palatine bones, medial plates of the pterygoid processes;

· from the inside on the side walls there are the upper, middle and lower nasal conchas, and below them the upper, middle and lower nasal passages.

Paranasal sinuses and their connections:

· the right and left maxillary sinuses open into the middle nasal passage through the semilunar clefts;

· frontal sinus – unpaired, communicates through the ethmoidal funnel with the middle nasal passage;

· the ethmoid sinus is unpaired, its anterior and middle cells flow through their openings into the middle nasal passage;

· sphenoid sinus – unpaired, through the sphenoethmoidal recess (bag) connects to the upper nasal passage;

· The ethmoid sinus (posterior cells) through the openings of the cells connects to the upper nasal passage.

The maxillary sinus is located inside the body of the upper jaw, communicates with the nasal cavity through the semilunar cleft, due to which the inhaled air in the sinus is moistened, purified, and heated, as in all other accessory cavities.

The superior wall separates the sinus from the orbit and consists of:

· from a compact bone 0.7-1.2 mm thick, with a thickening in the infraorbital margin;

· the infraorbital groove and canal pass through the upper wall, which thin the wall until it is absent; inside it, from the infraorbital canal and groove, the upper alveolar canaliculi (2-3) begin for the vessels and nerves of the same name that supply the alveoli and teeth.

The medial wall borders the nasal cavity and consists of:

· compact bone, thinner along the lower and posterior edge (1.7-2.2 mm) and thicker in front (3 mm), where the canine alveolus is located;

· in the wall there is a crescent-shaped maxillary cleft, connecting the sinus with the middle nasal passage.

The anterolateral wall is located in the area of ​​the canine fossa and consists of:

· from compact bone - thin in the center (0.2 mm) and thick along the periphery (4.8-6.4 mm), where at the frontal, zygomatic and alveolar processes the bone consists not only of outer and inner compact plates, but also spongy located between them bone tissue, which together form buttresses - bone seals that arise from the action of the masticatory muscles (frontonasal and zygomatic-alveolar);

· inside the wall there are anterior and middle alveolar tubules containing the vessels and nerves of the same name.

The posterolateral wall is located in the area of ​​the tubercle of the upper jaw and consists of:

· from one compact plate of 0.8-1.3 mm in the area of ​​the tubercle, and near the alveolar and zygomatic processes it has two compact plates, and between them a spongy substance, which gives it a significant thickness of 3.8-4.7 mm (buttress – pterygopalatine);

· inside the wall there are posterior alveolar canaliculi for the vessels and nerves of the same name; they thin the wall until it is absent.

The inferior wall is considered to be the junction of the lateral and medial walls in the form of a groove and consists of:

· from a compact plate 0.3–0.5 mm thick;

· the lower wall is considered as the bottom of the maxillary sinus, which can be low (deep), high (superficial), smooth or uneven due to protrusions of the alveoli of the incisors, canines and premolars.

Through the lower wall, the roots of the upper pre- and molars can adhere to the sinus, separated from it by a compact plate 2-3 mm thick, and if there are palatal and alveolar bays in the sinus, they can penetrate into it.

Individual variability in the structure of the maxillary sinus is manifested:

· with strong pneumatization of the jaw with a large volume of the sinus and thin walls;

· with weak pneumatization with small volume and thick walls;

· with a narrow and high jaw, a small sinus, the roots of the pre- and molars are separated by a thick lower wall;

· with a wide and low jaw and a large sinus, the lower wall becomes thinner, and in the presence of deep alveolar and palatal bays, the roots of the 2nd and 3rd molars lie inside the sinus.

When inhaling, the accessory nasal cavities receive atmospheric air, warming it, clearing it of dust, germs, moisturizing it, and only after passing through the nasal cavity and its accessory sinuses he goes to the lower Airways and lungs. In addition, the paranasal sinuses play the role of resonators during speech production. They also, thanks to their box-like structure and rational arrangement, lighten the structure of the skull and help it with biomechanical stability, both under natural and extreme loads.

For paranasal sinuses characterized by late and prolonged formation in ontogenesis.

Only the maxillary sinus appears in the fetal period (5th month), all the rest after birth: cells of the ethmoid sinus in infancy(9-12 months) and, in the first two years early childhood, sphenoid sinus - at the 3rd year of life, frontal sinus - at 12-14 months. The final formation of the sinuses occurs in puberty and adolescence, and some later, for example, the sphenoid develops by the age of 25-30.

Variants and anomalies

· rare absence, for example, of the frontal sinus;

· variations in size, volume, number of partitions inside the sinuses, wall thickness, bay-shaped protrusions;

Variations in the flow into the nasal passages;

· location inside the sinuses of other organs, for example, molars in the maxillary sinus.

The outer boundary between the vault and the base of the skull passes through:

· nasofrontal suture and nasion point;

· supraorbital edges of the frontal bone and its zygomatic processes, sphenoid-zygomatic suture;

· infratemporal crest of the sphenoid bone, zygomatic process of the temporal bone and external auditory foramen;

base of the mastoid process;

· superior nuchal line and external occipital protuberance.

The internal boundary between the arch and the base is not highlighted in all textbooks:

· the blind foramen of the frontal bone and the base of its orbital processes;

· connection of the small and large wings of the sphenoid bone (lateral tip of the superior orbital fissure), junction of the parietal-sphenoid and frontoparietal sutures;

· base of the pyramid of the temporal bone and mastoid-parietal suture;

· groove of the transverse sinus, cruciate eminence and internal protrusion of the occipital bone.

In the internal base there are three cranial pits located in ledges.

The anterior cranial fossa is formed by:

· on the sides - by the orbital parts of the frontal bone;

· in the center - a perforated plate of the ethmoid bone;

· behind - the small wings of the sphenoid bone.

Posterior border of the anterior cranial fossa:

· posterior edge of the lesser wings, tubercle of the sella of the sphenoid bone.

Anatomical structures of the anterior fossa:

· cerebral elevations, digital impressions, - traces of convolutions and grooves of the frontal lobe;

lattice holes for olfactory nerves(I pair);

· cock's comb and foramen cecum for the attachment of the dura mater.

The middle cranial fossa is formed by the body and large wings of the sphenoid bone, the anterior surface of the pyramid and part of the squama of the temporal bone. The pit has a central part with the sella turcica and two lateral fossae: right and left.

In the central part of the body of the sphenoid bone there is the sella turcica and a number of other formations:

· in front of the sella turcica - the pre-cross groove and the anterior tubercle - for the chiasm of the optic nerves and the anterior part of the cavernous venous sinus;

· openings of the optic canals for the second pair of cranial nerves and central arteries and veins;

· the pituitary fossa and behind it the dorsum of the sella turcica - for the pituitary gland and the posterior part of the cavernous sinus;

· on the sides of the sella - carotid grooves right and left - for the internal carotid artery and the lateral parts of the cavernous sinus (the artery passes inside the sinus).

In two lateral pits on the large wings and the pyramid are located:

· cerebral eminences and digital impressions of the temporal lobe of the brain;

· between the greater and lesser wings - the superior orbital fissure - for the III, IY, YI pairs and the first (ophthalmic) branch of the Y pair of cranial nerves, ophthalmic arteries and veins;

· round foramen – maxillary branch of the Y pair;

· foramen ovale - mandibular branch of the Y pair and finely looped venous plexus;

Foramen spinosum - middle meningeal artery;

· clefts and grooves for the greater and lesser petrosal nerves (branches of the YII and IX pairs), trigeminal depression for the node of the Y pair on the anterior surface at the apex of the pyramid of the temporal bone, the roof of the tympanic cavity and the arcuate eminence.

Posterior cranial fossa

The anterior border runs along the upper edges of the pyramids of the temporal bone and the dorsum of the sphenoid. The posterior border is along the internal occipital protuberance and the groove of the transverse sinus. The relief of the fossa is formed due to the inner surface of the occipital bone, the posterior surfaces temporal pyramids, the inner surface of the mastoid processes, the body of the sphenoid bone and the mastoid angles of the occipital bone.

Anatomical structures:

· clivus - formed due to spheno-occipital synchondrosis at the connection of the basilar part of the occipital bone and the back of the sella turcica of the sphenoid bone, serves as a bed for the medulla oblongata and the pons (hindbrain);

foramen magnum, through which medulla passes into the spinal column, accompanied by paired vertebral vessels;

· the internal nuchal crest separates the right and left inferior occipital fossae - for the cerebellar hemispheres;

· cruciform eminence with internal occipital protrusion - for attachment of the dura mater with the fusion of the sinuses (sinus drainage);

· grooves of the same name - for paired (right and left) transverse and sigmoid sinuses;

· internal auditory opening and passage for YII, YIII pairs of cranial nerves, groove of the inferior petrosal sinus, external aperture of the vestibule aqueduct and subarcicular fossa;

· jugular foramen(right and left) - for the IX, X, XI pairs and the internal jugular vein.

The bony thickenings of the skull that resist the load and redistribute it are called buttresses. Their biomechanical properties are determined by the presence of compact plates: outer and inner, between which there is a spongy substance. The smooth curvilinearity of the compact plates and the thickness of the spongy substance are of decisive importance in the stability of buttresses. The orientation of the bone beams strictly corresponds to the load lines.

In the facial skull there are (on the upper jaw):

· the frontonasal buttress, which rests on the alveolar elevations in the canine area, continues along the compact plate of the frontal process to the nasal part of the frontal bone, where it is strengthened by transversely directed bony ridges of the brow ridges;

· alveolar-zygomatic buttress - from the alveolar eminence in the region of 1-2 molars along the zygomatic-alveolar ridge to the zygomatic bone, from it to the zygomatic process of the frontal bone and the lower orbital edge of the upper jaw;

· pterygopalatine buttress - from the alveolar eminence of 2-3 molars, through the tubercle of the upper jaw to the pterygoid process of the sphenoid bone and perpendicular to the plate of the palatine bone;

· the palatal buttress with the transverse direction of the bone beams and force trajectories arises due to the palatine processes of the upper jaw and the horizontal plates of the palatine bone.

On the lower jaw there are:

· alveolar buttress – from the basilar arch at the base of the jaw upward to its alveolar part;

· ascending - along the basilar arch and processes of the branches.

In the brain skull, the buttresses of the vault and the base are distinguished:

· the longitudinal sagittal buttress rests on the nasal part of the frontal bone, runs in the middle between the frontal tubercles and further along the sagittal suture, ending in the area of ​​the occipital protrusions;

· the frontoparietal buttress begins at the base of the zygomatic process of the frontal bone, passes through the frontal tubercle, the temporal line to the parietal tubercle and ends at the mastoid process of the temporal bone;

· the anterolateral buttress of the base is formed by the small wings and the infratemporal crest of the large wings of the sphenoid bone;

· the posterolateral buttress of the skull base is created by the root of the zygomatic process and the base of the pyramid and mastoid process of the temporal bone.

· The occipital buttress of the base is formed by the nuchal ridges, condyles, clivus, and ridges around the foramen magnum.

Between the buttresses are thinner areas of the skull bones, which are often called “weak spots” because fracture lines pass through them. The combination of thick and thin areas in the bony relief of the skull, together with its general rounded shape, slowly and gradually ossifying sutures and synchondrosis, allows it to withstand significant mechanical loads.

Therefore, in the human skull there are anatomical devices that perform the function of biomechanical devices that resist the effects of mechanical energy(Yu. F. Chernikov). They include not only the buttresses listed above, but also:

· rational overall shape: a round (brachycranial) skull evenly distributes the load, an oval (dolichocranial) skull concentrates it more at the base;

· alternating throughout the entire skull the ratio of the thickness of the bones to the radius of curvature, namely, the smoother the external and internal contour of the skull is formed and the thicker the bones, the stronger the entire structure, and vice versa, which is more typical for the base;

· the peculiar shape of the air cavities, which play the role of light, high-strength box-like structures at the border of the vault and the base of the brain and facial skull;

· systemic arrangement of holes in the base in longitudinally parallel, stepped rows and the presence of bone thickenings of various sections around the holes, which causes the interaction of elastic compression fields in the base area and increases its biomechanical stability;

· the presence of supporting and connecting nodes and thin arches between them, having a triangular and diamond-shaped cross-section with load-oriented bone beams;

· construction of sutures and synchondroses from connective and cartilaginous tissues, providing shock-absorbing properties of continuous joints, which throughout life undergo gradual and slow ossification, which determines a strictly defined sequence of their inclusion in the load and its rational redistribution during skull deformations;

· general stressed state of the skull: the presence in the bones of tensile stresses along the outer plate and compressive stresses along the inner plate, the topography of which depends on the shape of the bones and the skull as a whole, gender and age of the person;

· redistribution of force stresses and deformations depending on the shape, structure of the bones and the entire skull, as well as the direction, strength and speed of the acting load.

In the brain skull they are distinguished according to the vertical norm:

· vault or roof - a dome-shaped upper part formed by the scales of the frontal, temporal, occipital bones, large wings of the sphenoid and parietal bones; with dolichocrania, the shape of the vault is ellipsoidal, with mesocrania – ovoid, with brachycrania – spheroid;

· according to the basilar norm - the external and internal base formed by the orbital parts of the frontal bone, the ethmoid bone, the upper jaws and palatine bones, the sphenoid, the pyramids of the temporal bones, the basilar and lateral parts, the squama of the occipital bone.

The outer border between the arch and the base runs along the nasofrontal suture, supraorbital edges, zygomatic processes of the frontal bone, infratemporal crest of the sphenoid, along the base of the zygomatic processes of the temporal bones, above the external auditory foramen (along the upper edge), through the base of the mastoid processes; ends along the superior nuchal line and the external occipital protrusion.

In the code of outer surface distinguish the anterior section (forehead - frontal region) with relief:

· scales of the frontal bone - on it are the frontal tubercles, right and left;

· brow ridges at the border with the facial skull and between them the glabella (glabella);

· zygomatic processes and temporal lines: upper and lower;

· coronal serrated suture and a rare metopic suture.

IN upper section vault (vertex - parietal region) relief is created by:

· parietal tubercles, sagittal serrated suture;

· upper and lower temporal lines - with an arched and parallel arrangement.

The lateral section of the vault (temporo-temporal region) has:

· large wings of the sphenoid bone and scales of the temporal bone, - scaly suture and temporal edge parietal bones;

· temporal fossa, filled with temporal muscle and tissue, infratemporal crest, zygomatic arch;

· mastoid angle of the parietal bone and the base of the mastoid process.

The posterior section of the fornix (occiput - occipital region) contains:

· posterior edges of the parietal bones;

· squama of the occipital bone and lambdoid serrated suture;

· external occipital protuberance and superior nuchal line.

The inner surface of the fornix (cerebral) has:

· sutures: sagittal, coronal, lambdoid, scaly, less and less noticeable with age;

· finger-shaped impressions and cerebral elevations - imprints of the cerebral convolutions and grooves between them;

· arterial grooves and venous groove of the superior sagittal sinus, dimples of granulations;

· superior occipital fossa for the occipital lobes of the brain.

Temporal bone canals. Sleepy canal (canalis caroticus), through which the internal carotid artery and internal carotid (vegetative) plexus pass into the cranial cavity, begins on the lower surface of the pyramid with the external opening of the carotid canal. Next, the carotid canal rises upward, bends at a right angle, and goes forward and medially. The canal opens into the cranial cavity through the internal carotid foramen.

Musculo-tubal canal (canalis musculotubarius) has a common wall with the carotid canal. It begins at the anterior edge of the pyramid near its border with the squama of the temporal bone, runs posteriorly and laterally, parallel to the anterior edge of the pyramid. The myotubal canal is divided by a septum into two half-canals. Upper semicanal (semicanalis musculi tensoris tympani) is occupied by the muscle of the same name, straining the tympanic membrane, and the lower one - semicanal of the auditory tube (semicanalis tubae auditivae) is the bony part of this tube. Both half-channels open into the tympanic cavity on its anterior wall.

Facial canal (sapalis facialis), in which the facial nerve and blood vessels pass, begins at the bottom of the internal auditory canal. Then, in the thickness of the pyramid of the temporal bone, the facial canal runs horizontally forward, perpendicular to the longitudinal axis of the pyramid. Having reached the level of the cleft of the canal of the greater petrosal nerve, the canal goes laterally and posteriorly at a right angle, forming a bend, or knee of the facial canal (geniculum canalis facialis). Next, the canal follows horizontally backward along the axis of the pyramid to its base, where it turns vertically downward, bending around the tympanic cavity. On the lower surface of the pyramid the canal ends with the stylomastoid foramen.

Cord tympani canaliculus (canaliculus chordae tympani) starts from the canal of the facial nerve slightly above the stylomastoid foramen, goes forward and opens into the tympanic cavity. A branch of the facial nerve passes through this canaliculus - drum string (сhorda tympani), which then exits the tympanic cavity through the petrotympanic fissure.

Tympanic tubule (canaliculus tympanicus) begins with a lower opening in the depths of the stony dimple on the lower surface of the pyramid, then rises upward into the tympanic cavity through its lower wall. Further, the canaliculus continues in the form furrows (sulcus promontorii), on the labyrinthine wall of this cavity on the surface cape (promontorium). The Canadian then pierces the upper wall of the tympanic cavity and ends in the cleft of the lesser petrosal nerve canal on the anterior surface of the pyramid. The tympanic canaliculus contains the tympanic nerve, a branch of the glossopharyngeal nerve.

Mastoid tubule (capaliculus mastoideus) originates in the jugular fossa, crosses the facial canal in its lower part and opens into the tympanomastoid fissure. The auricular branch passes through this canaliculus
vagus nerve.

Carotid-tympanic tubules (canaliculi caroticotympanici) begin on the wall of the carotid canal (near its external opening) and penetrate the tympanic cavity. Both tubules serve to pass the nerves and arteries of the same name into the tympanic cavity.

1. The front surface of the pyramid, fades anterior partis petrosae. Rice. A, V.
2. Roof of the tympanic cavity, tegmen rympani. A thin plate of bone anterior and lateral to the arcuate eminence. Rice. IN.
3. Arc-shaped elevation, eminentia arcuaia. Lies on the front surface of the pyramid. Corresponds to the anterior semicircular canal. Rice. A, V.
4. Cleft of the canal of the greater petrosal nerve, hiatus canalis n. petrosi majoris. The hole on the anterior surface of the pyramid through which the nerve of the same name passes. Rice. A, V.
5. Cleft of the canal of the lesser petrosal nerve, hiatus canalis n. petrosi minoris. An opening on the anterior surface of the pyramid, below the cleft of the canal of the greater petrosal nerve. Rice. A, V.
6. Groove of the greater petrosal nerve, sulcus n.petrosi majoris. It is directed from the corresponding cleft forward and medially to the lacerated foramen. Rice. IN.
7. Groove of the lesser petrosal nerve, sulcus n.petrosi minoris. It is directed from the corresponding cleft to the foramen ovale. Rice. IN.
8. Trigeminal depression, impresio trigeminalis. A depression on the anterior surface of the pyramid at its apex for the trigeminal nerve ganglion. Rice. IN.
9. The upper edge of the pyramid, margo superior partis petrosae. Rice. A, V.
10. Groove of the superior petrosal sinus, sulcus sinus petrosi superioris. Runs along the top edge of the pyramid. Rice. A, V.
11. Rear surface of the pyramid, fades posterior partis petrosae. Rice. A.
12. Internal auditory opening, porus acusticus internus. Lies on the back surface of the pyramid. Rice. A.
13. Interior ear canal, meatus acusticus internus. Contains VII, VIII cranial nerves and vessels. Rice. A.
14. Subarc fossa, fossa subarcuata. The depression above the internal auditory canal. Filled with a piece of cerebellum. Rice. A.
15. Aqueduct of the vestibule, aqueductus vestibuli. Narrow channel in back wall pyramid, communicating with the endolymphatic space of the inner ear.
16. External aperture of the aqueduct of the vestibule, apertura externa aqueductus vestibuli. Rice. A.
17. Posterior edge of the pyramid, margo posterior partis petrosae. Rice. A, B.
18. Groove of the inferior petrosal sinus, sulcus sinus petrosi inferioris. Rice. A.
19. Jugular notch, incisura jugularis. Forms the anterior edge of the jugular foramen. Rice. A, B.
20. Intrajugular process, processus intrajugularis. Divides the jugular foramen into two sections: the jugular vein passes through the posterolateral section, and the IX, X, XI cranial nerves pass through the anteromedial section. Rice. A, B.
21. Snail canaliculus, canaliculus cochleae. Contains the perilymphatic duct.
22. External aperture of the cochlear canaliculi, apertura externa canaliculi cochleae. Located anterior and medial to the jugular fossa. Rice. B.
23. The lower surface of the pyramid, fades inferior partis petrosae. Rice. B.
24. Jugular fossa, fossa jugularis. Lies near the jugular notch. Contains the superior bulb of the internal jugular vein. Rice. B.
25. Mastoid tubule, canaliculus mastoideus. Originates in the jugular fossa. Contains the auricular branch of the vagus nerve. Rice. B.
26. Styloid process, processus styloideus. Located lateral and anterior to the jugular fossa. It is a derivative of the second gill arch. Rice. A, B, G.
27. Stylomastoid foramen, foramen stylomastoideum. Located behind the styloid process between the mastoid process and the jugular fossa. It is the external opening of the facial canal. Rice. B.
28. Tympanic tubule, canaliculus tympanicus. Begins in a stony dimple. Contains the tympanic nerve and the inferior tympanic artery. Rice. B.
29. Stony dimple, fossula petrosa. Located on the bony ridge between the external opening of the carotid canal and the jugular fossa. Contains a tympanic thickening of the glossopharyngeal nerve. Rice. B.
30. Tympanic cavity, cavitas tympanica. The narrow, air-containing space between the bony labyrinth and the eardrum.
31. Petrostympanic [[glaser]] fissure, fissura petrotympanica []. Located between the tympanic part and the bony plate of the petrous part of the temporal bone, dorsomedial to the mandibular fossa. Rice. B, G.
32. Stony-scaly fissure, fissura petrosquamosa. Located at the base of the skull, anterior to the petrotympanic fissure, between the bony plate of the petrous part and the squamosal part of the temporal bone. Rice. B, V.
33. Tympanosquamous fissure, fissura tympanosquamosa. It is formed when the above-mentioned two slits merge. Rice. B, G.
34. Tympanomastoid fissure, fissura tympanomastoidea. Located between the tympanic part and the mastoid process. The origin of the auricular branch of the vagus nerve. Rice. B, G.

Sleepy channel. Connects the outer base of the skull and the apex of the pyramid of the temporal bone. The canal contains the internal carotid artery, the internal carotid plexus.

^ Musculo-tubal canal. Connects the apex of the temporal bone pyramid and the tympanic cavity. The canal contains the tensor tympani muscle and the auditory tube.

^ Carotid-tympanic tubules. Connect the carotid canal and the tympanic cavity. The canal contains the carotid-tympanic nerves and plexuses.

Internal auditory canal. Connects the posterior cranial fossa and inner ear. The canal contains the facial nerve, vestibulocochlear nerve, artery and vein of the inner ear.

^ Facial canal. Connects the posterior surface of the pyramid of the temporal bone and the stylomastoid foramen. The facial nerve passes through Canada.

Drum string channel. Connects the facial canal, the tympanic cavity and the petrotympanic fissure. In Canada there is a chorda tympani and a branch of the facial nerve.

^ Tympanic canaliculus. Connects the lower surface of the pyramid of the temporal bone, the tympanic cavity and the anterior surface of the pyramid. In Canada there is a branch of the glossopharyngeal nerve and the lesser stone nerve.

^Mastoid canal. Connects the jugular fossa and the tympanomastoid fissure. The auricular branch of the vagus nerve passes through the canal.

Plumbing vestibule. Connects the vestibule of the inner ear and the posterior cranial fossa. The canal contains the aqueduct of the vestibule and the vein of the aqueduct of the vestibule.

^ 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 cochlear canaliculus vein.

№ 18Sphenoid bone: its parts, holes and their purpose.

Sphenoid bone,os sphenoidale, located in the center of the base of the skull. It participates in the formation of the lateral walls of the cranial vault, as well as the cavities and fossae of the cerebral and facial parts 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 there is a cavity - the sphenoid sinus, sinus sphenoidalis. There are 6 surfaces in the body: the upper, or cerebral; posterior, fused in adults with the basilar (main) part of the occipital bone; the front one, which passes without sharp boundaries into the lower one, and two lateral ones.

^ Small wing, ala minor, It is a paired plate extending from each side of the body of the sphenoid bone with two roots. Between the latter is the visual channel, canalis opticus, for the passage of the optic nerve from the orbit. The anterior edges of the lesser wings are serrated; the orbital parts of the frontal bone and the cribriform plate of the ethmoid bone are connected to them. The posterior edges of the small wings are free and smooth. On the medial side of each wing there is an anterior inclined process, processus clinoideus anterior. The dura mater 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 lesser and greater wings is the superior orbital fissure, fissura orbitalis superior. The oculomotor, lateral and abducens nerves (III, IV, VI pairs of cranial nerves) and the optic nerve - I branch of the trigeminal nerve (V pair) pass through it from the cranial cavity to the orbit.

^ 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 there is a round hole, foramen rotundum, through which the second branch of the trigeminal nerve passes, in the middle of the wing there is the foramen ovale, foramen ovale, for the third branch of the trigeminal nerve. Foramen spinosum, foramen spinosum, smaller in size, located in the region of the posterior corner of the large wing. Through this opening, the middle meningeal artery enters the cranial cavity.

The large wing has four surfaces: medullary, orbital, maxillary and temporal. On the surface of the brain fades cerebralis, finger-shaped impressions are well defined, impressidnes digitatae, and arterial grooves, sulci arteriosi. orbital surface, fades orbitalis,- quadrangular smooth plate; 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 opening opens. Temporal surface, fades tempordlis, the most extensive. infratemporal crest, crista infratemporalis, 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 and forms the upper wall of the infratemporal fossa.

^ Pterygoid process,processus pterygoideus, paired, departs from the body of the sphenoid bone at the beginning of the large wing and is directed vertically downward. The medial plate of the process faces the nasal cavity, the lateral plate faces the infratemporal fossa. The base of the process is pierced from front to back by a narrow pterygoid canal, canalis pterygoideus, in 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 anterior plates are fused. Posteriorly, the plates of the pterygoid process diverge, forming the pterygoid fossa, fossa pterygoidea. At the bottom, 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 below passes into the pterygoid hook, Hamulus pterygoideus.

№ 19 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, the medial wall is the perpendicular plate of the palatine bone. On the lateral side, the pterygopalatine fossa does not have a bone wall and communicates with the infratemporal fossa. The pterygopalatine fossa gradually narrows downwards and passes into the greater palatine canal, canalis palatinus major, which at the top has the same walls as the fossa, and at the bottom it is delimited by the upper jaw (laterally) and the palatine bone (medially). Five openings enter 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 the round foramen, posteriorly with the region of the foramen lacerum via the pterygoid canal, and inferiorly with the oral cavity through the greater palatine canal.

The pterygopalatine fossa is connected to the orbit through the inferior orbital fissure.

№ 20 The nasal cavity, the structure of its walls. Paranasal sinuses, their meaning, variants and anomalies.

nasal cavity, cavum nasi, occupies a central position in facial area skulls Bone septum of the nose, septum ndsi osseum, consisting of a perpendicular plate of the ethmoid bone and a vomer, fixed below on the nasal ridge, 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 pyriform aperture, the anterior nasal spine protrudes forward, spina nasalis anterior. Through the posterior openings, or choanae, shoapae, 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, above by the body of the sphenoid bone, and below by the horizontal plate of the palatine bone.