The sphenoid bone is characterized by the following features. Sphenoid bone of the skull. Functions of the sphenoid bone

1. Pterygoid process, processus pterygoideus. Rice. A, B.
2. Lateral plate [of the pterygoid process] lamina lateralis. Rice. A, B.
3. Medial plate [of the pterygoid process], lamina medialis. Rice. A, B.
4. Pterygoid notch, incisura pterygoidea. It is located between the two plates of the pterygoid process and is directed downward. Filled with the pyramidal process os palatinum. Rice. A.
5. Pterygoid fossa, fossa pterygoidea. Located between the lateral and medial plastics. Place of attachment of m.pterygoideus medialis. Rice. A, B.
6. Scaphoid fossa, fossa scaphoidea. Depression at the base of the medial plate of the pterygoid process. The starting point of mjensor veli palatini. Rice. A.
7. Vaginal process, processus vaginalis. Located on the inner side of the base of the medial plate of the pterygoid process. Rice. A, B.
8. Palatovaginal groove, sulcus palatovaginal. Together with the palatine bone, it forms the canal of the same name. Rice. B.
9. Vomer - vaginal groove, sulcus vomerovaginal. It is located at the base of the pterygoid process and, together with the vomer, forms the canal of the same name. Rice. B.
10. Wing-shaped hook, hamulus pterygoideus. It is located at the end of the medial plate of the pterygoid process and is directed downward. Rice. A, B.
11. Furrow of the pterygoid hook, sulcus hamuli pterygoidei. Formed due to a sharp bend of the wing-shaped hook. Rice. B.
12. Pterygoid [[vidian]] canal, canalis pterygoideus []. Passes at the base of the pterygoid process towards the pterygopalatine fossa. Contains the large and deep petrosal nerves Fig. A. See fig. IN.
13. Pterygospinous process, processus pterygospinosus. A sharp projection on the posterior edge of the lateral plate of the pterygoid process. Rice. A.
14. Temporal bone, os temporale. Located between the occipital, sphenoid and parietal bones. Consists of stony, drum and scaly parts. Rice. B, G, D.
15. Pyramid (rocky part), pars petrosa. Contains the organ of hearing and balance. Rice. G.
16. Occipital margin, margo occipitalis. Connects to the occipital bone. Rice. V, G.
17. Mastoid process, processus mastoideus. Located behind the external auditory canal. Rice. V, D.
18. Mastoid notch, incisura mastoidea. Located on the lower surface of the pyramid, medial to the mastoid process. Place of origin of the posterior abdomen m.digastricus. Rice. IN.
19. The groove of the sigmoid sinus, sulcus sinus sigmoidei. Rice. G.
20. Groove of the occipital artery, sulcus a.occipitalis. Located at the occipital edge of the pyramid, the medial mastoid notch. Rice. IN.
21. Mastoid foramen, foramen mastoideum. Located behind the mastoid process. Contains an emissary vein. Rice. V, G.
22. Facial canal, canalis facialis. It begins in the internal auditory canal and ends with the stylomastoid foramen. Contains the nerve of the same name. Rice. B, G, D.
23. The genu of the facial canal, geniculum canalis facialis. The bend of the facial canal at the anterior wall of the pyramid, near the cleft of the greater petrosal nerve. Rice. G.
24. The canaliculus chordae tympani. A narrow passage connecting the facial canal and the tympanic cavity. Contains drum string. Rice. G, D.
25. The tip of the pyramid, apex partis petrosae. Directed forward and medially. Rice. V, G.
26. Sleepy canal, canalis caroticus. It begins on the outer base of the skull between the jugular foramen and the myotubal canal. Contains the internal carotid artery. Rice. IN.
27. Carotid-tympanic tubules, canaliculi caroticotympanic. They pass through the wall of the carotid canal. Contains vessels and nerves going into the tympanic cavity. Rice. IN.
28. Musculo-tubal canal, canalis musculotubarius. It is located in front of the carotid canal and leads into the tympanic cavity. Contains the auditory tube and the tensor tympani muscle. Rice. V, D.
29. The semicanal of the tensor tympani muscle, semicanalis m.tensoris tympani. Rice. D.
30. Hemicanal of the auditory tube, semicanalis tubae auditoriae (auditivae). Rice. D.
31. The septum of the muscular-tubal canal, septum canalis musculotubarii. Bone wall, between the above-mentioned hemicanals. Rice. D.

Body of the sphenoid bone, corpus ossis sphenoidalis, the middle part of the bone, cubic in shape, has six surfaces. The upper surface of the body, facing the cranial cavity, has a depression in its middle sections - the sella turcica, sella turcica. in the center of which is the pituitary fossa. It contains the pituitary gland. The size of the fossa is determined by the size of the pituitary gland. The pituitary fossa is especially vulnerable in the case of premature birth. The fusion of the two ossification nuclei of the fossa occurs in the 8th month of intrauterine life. This raises the possibility of damage to the structure of the pituitary fossa with subsequent dysfunction of the pituitary gland. The sella turcica is limited in front by the tubercle of the sella, tuberculum sellae. Posterior to it, on the lateral surface of the saddle, there is a non-constant middle inclined process, processus clinoideus medius. Anterior to the tubercle sella there is a shallow transverse groove of the decussation, sulcus chiasmatis. It lies on the optic chiasm, chiasma opticum. On the sides the groove passes into the optic canal, canalis opticus. In front of the furrow there is a smooth surface - a wedge-shaped eminence, jugum sphenoidale, connecting the small wings of the sphenoid bone. The anterior edge of the upper surface of the body is serrated, protrudes slightly forward and connects with the posterior edge of the perforated plate, lamina cribrosa, ethmoid bone, forming a sphenoethmoidal suture, sutura sphenoethmoidalis. The perforated plate has a large number of holes (25-30), through which the branches of the anterior ethmoidal (olfactory) nerve and the vein accompanying the anterior ethmoidal artery go from the nasal cavity to the cranial cavity (there are olfactory grooves on the sides of the anterior edge of the sphenoid bone). If the sense of smell is impaired or absent, the kinetics of the anterior edge of the sphenoid bone should be checked. As a result of injury to the frontal bone, a violation of the relationship in the sphenoid-ethmoidal suture may occur with subsequent trauma to the olfactory bulbs.

The sella turcica is limited at the back by the back of the saddle, dorsum sellae, which ends on each side with a small posterior inclined process, processus clinoideus posterior. On the sides of the sella turcica, from back to front, runs the carotid groove, sulcus caroticus(imprint of the internal carotid artery located here and the accompanying nerve plexus).

Rice. Sphenoid bone (according to H. Feneis, 1994): 1 – body; 2 – wedge-shaped eminence; 3 – large wing, 4 – small wing; 5 – precross groove; 6 – sella turcica; 7 – pituitary fossa; 8 – anterior inclined process; 9 – posterior inclined process; 10 – back of the saddle; 11 – carotid groove; 12 – wedge-shaped ridge; 13 – wedge-shaped beak; 14 – aperture of the sphenoid sinus; 15 – visual channel; 16 – superior orbital fissure; 17 – brain surface; 18 – temporal surface; 19 – orbital surface; 20 – zygomatic edge; 21 – frontal edge; 22 – parietal edge; 23 – scaly edge; 24 – infratemporal crest; 25 – round hole; 26 – oval hole; 27 – foramen spinosum; 28 – spine of the sphenoid bone; 29 – pterygoid (vidian) canal; 30 – pterygoid process; 31 – lateral plate of the pterygoid process; 32 – medial plate of the pterygoid process; 33 – pterygoid hook; 34 – pterygoid notch; 35 – wedge-shaped surface of sphenobasilar synchondrosis.

The posterior surface of the dorsum sella passes into the upper surface of the basilar part of the occipital bone, forming a slope, clivus. On the slope there is a bridge, medulla oblongata, and basilar artery with its branches. The posterior surface of the body is rough. Through a cartilaginous layer, it connects to the anterior surface of the basilar part of the occipital bone, forming the sphenoid-occipital synchondrosis (SSO), synchondrosis sphenooccipitalis. More often in the osteopathic literature and among osteopaths, another term is found - sphenobasilar symphysis. Despite the existence of the International Nomenclature, the latter anatomical term has taken root and is most common among osteopaths. It is believed that by the age of 25, the cartilage is replaced by bone tissue and the two bones fuse together. However, there is still no consensus on this issue. It is likely that the bones are still not completely fused.

The front and part of the lower surface of the body are facing the nasal cavity. In the middle of the front surface of the body there is a vertically running wedge-shaped crest, crista sphenoidalis. Its anterior edge is adjacent to the posterior edge of the perpendicular plate, lamina perpendicularis, ethmoid bone. The lower segment of the crest is pointed, extended downwards, and forms a wedge-shaped beak, rostrum sphenoidale, which is wedged between the wings of the opener, alae vomeris. On the sides of the ridge lies a thin curved plate - a wedge-shaped shell, concha sphenoidalis. This shell, forming the anterior and partly lower walls of the sphenoid sinus, sinus sphenoidalis, has a small opening - the aperture of the sphenoid sinus, apertura sinus sphenoidalis. Outside the aperture there are small depressions that cover the cells of the posterior part of the labyrinth of the ethmoid bone. The outer edges of these recesses are partially connected to the orbital plate of the ethmoid bone, forming a sphenoethmoidal suture, sutura sphenoethmoidalis, and the lower ones - with the orbital process, processus orbitalis, palatine bone.

sphenoid sinus, sinus sphenoidalis, a paired cavity, fills most of the body of the sphenoid bone and belongs to the air-bearing paranasal sinuses. Both, right and left, sinuses are separated from one another by the septum of the sphenoid sinuses, which anteriorly continues into the sphenoid crest. As in the frontal sinuses, the septum sometimes lies asymmetrically, as a result of which the size of both sinuses may not be the same. Through the aperture, the cavity of each sphenoid sinus opens into the nasal cavity. The cavity of the sphenoid sinus is lined with mucous membrane.

Small wings, alae minores, the sphenoid bone has two roots extending in both directions from the anterior-superior corners of the body in the form of two horizontally located plates, at the base of which there is a rounded hole. It represents the beginning of a bone canal up to 5-6 mm long - the optic canal, canalis opticus. It contains the optic nerve, n. opticus, and ophthalmic artery, a. ophthalmica. The small wings have an upper surface facing the cranial cavity and a lower surface directed into the orbital cavity and closing the superior orbital fissure from above, fissura orbitalis superior. The anterior edge of the lesser wing, thickened and jagged, connects to the orbital part of the frontal bone. The posterior concave and smooth edge protrudes freely into the cranial cavity and is the boundary between the anterior and middle cranial fossae, fossae cranii anterior et media. The medial posterior edge ends in a prominent, well-defined, anterior inclined process, processus clinoideus anterior(a part of the dura mater is attached to it, forming the diaphragm of the sella turcica, diaphragma sellae).

Large wings of the sphenoid bone, alae majores, extend from the lateral surfaces of the body of the sphenoid bone and are oriented outward. The large wing has five surfaces and three edges. Upper, medullary surface facies cerebralis, concave and facing the cranial cavity. It forms the anterior part of the middle cranial fossa and bears sulcal impressions, cerebral eminences and arterial grooves, sulci arteriosi(relief imprints of the adjacent surface of the brain and middle meningeal arteries). At the base of the large wing there are three openings: a round opening is located inwardly and anteriorly, foramen rotundum(the maxillary nerve exits through it, n. maxillaris). Outside and posterior to the round there is an oval foramen, foramen ovale (it passes the mandibular nerve, n. mandibularis, and the vascular network of the foramen ovale). Also lateral and posterior to the foramen ovale is the foramen spinosum, foramen spinosum(the middle meningeal artery, vein and nerve pass through it). Anterosuperior, orbital surface, facies orbitalis, smooth, diamond-shaped, facing the cavity of the orbit, where it forms most of its outer wall. The lower edge of this surface is distant from the posterior edge of the orbital surface of the body of the upper jaw; the inferior orbital fissure is formed here, fissura orbitalis inferior. Anterior, maxillary surface, facies maxillaris, a small triangular-shaped area, limited above by the orbital surface, and on the side and below by the root of the pterygoid process of the sphenoid bone. It is part of the posterior wall of the pterygopalatine fossa, fossa pterygopalatina. There is a round hole on the surface. Superolateral, temporal surface, facies temporalis, somewhat concave, takes part in the formation of the wall of the temporal fossa, fossa temporalis(the temporalis muscle is attached to it, m. temporalis). Below this surface is limited by the infratemporal crest, crista infratemporalis, below which is the surface where the foramen ovale opens, foramen ovale, and the foramen spinosum. It forms the superior wall of the infratemporal fossa, fossa infratemporalis. This is where part of the lateral pterygoid muscle begins, m. pterygoideus lateralis. The upper, frontal, edge is widely serrated, connected to the orbital part of the frontal bone in the sphenoid-frontal suture ( sutura sphenofrontalis). The outer sections of the frontal edge end with a sharp parietal edge, margo parietalis, which with the wedge-shaped angle of the parietal bone forms the sphenoid-parietal suture ( sutura sphenoparietalis). The internal sections of the frontal edge pass into a thin free edge, which is spaced from the lower surface of the lesser wing, limiting the superior orbital fissure from below fissura orbitalis superior. Anterior, zygomatic margin, margo zygomaticus, serrated, connected to the frontal process, processus frontalis, zygomatic bone, forming the sphenoid-zygomatic suture ( sutura sphenozygomatica). Posterior, scaly edge, margo squamosus, connects to the wedge-shaped edge, margo sphenoidalis, temporal bone in the sphenosquamosal suture ( sutura sphenosquamosa). Posteriorly and outwardly, the scaly edge ends with the spine of the sphenoid bone, spina ossis sphenoidalis. Here is the place of attachment of the sphenomandibular ligament, lig. sphenomandibulare, and bundles of the muscle that strains the velum palatine, m. tensor veli palatini. Inward to the spine of the sphenoid bone, the posterior edge of the greater wing lies in front of the petrous part, pars petrosa, temporal bone and limits the sphenoid-petrosal fissure, fissura sphenopetrosa, passing medially into the foramen lacerum, foramen lacerum. This gap is filled with cartilaginous tissue, forming a wedge-shaped petrosal synchondrosis, synchondrosis sphenopetrosa.

Pterygoid processes, processus pterygoidei, extend from the junction of the large wings with the body of the sphenoid bone and are directed downwards. The pterygoid processes are formed by two plates - lateral and medial. Lateral plate, lamina lateralis processus pterygoidei, wider, but thinner and shorter than the inner one (the lateral pterygoid muscle begins from its outer surface, m. pterygoideus lateralis). medial plate, lamina medialis processus pterygoidei, narrower, thicker and slightly longer than the outer one. Both plates grow together with their anterior edges and, diverging posteriorly, limit the pterygoid fossa, fossa pterygoidea(here begins the medial pterygoid muscle, m. pterygoideus medialis). In the lower sections, both plates do not fuse and limit the pterygoid notch, incisura pterygoidea, filled with a pyramidal process, processus pyramidalis, palatine bone. The free end of the inner plate ends with a wing-shaped hook directed downwards and outwards, hamulus pterygoideus, on the outer surface of which there is a groove of the pterygoid hook, sulcus hamuli pterygoidei(the tendon of the muscle that strains the velum palatine is thrown through it, m. tensor veli palatini). The posterior-superior edge of the inner plate at the base expands and forms an oblong scaphoid fossa, fossa scaphoidea(bundles of muscles that strain the velum palatine begin in it, m. tensor veli palatini). Outward from the navicular fossa there is a shallow groove of the auditory tube, sulcus tubae audilivae, which laterally passes onto the greater wing and reaches the spine of the sphenoid bone (the cartilaginous part of the auditory tube is adjacent to this groove). Above the scaphoid fossa and medial from it there is an opening leading to the pterygoid canal, canalis pterygoideus(vessels and nerves pass through it). The canal runs in the sagittal direction in the thickness of the base of the pterygoid process and opens on the maxillary surface of the large wing of the sphenoid bone on the posterior wall of the pterygopalatine fossa. Under the exit opening, along the anterior edge of the pterygoid process, is the pterygopalatine groove. The internal plate at its base gives off an inwardly directed flat horizontally running vaginal process, processus vaginalis, which is located under the body of the sphenoid bone, covering the side of the vomer wing. As a result of this, the groove of the vaginal process facing the wing is the vomerovaginal groove, sulcus vomerovaginalis, turns into the vomerovaginal canal, canalis vomerovaginalis. Outside of the process there is sometimes a small sagittal sulcus running sagittally, sulcus palatovaginalis. In the latter case, the sphenoid process of the palatine bone, adjacent below, closes the groove into the canal of the same name (in both canals there are nerve branches of the pterygopalatine ganglion, and in the palatovaginal canal there are also branches of the sphenopalatine artery). Sometimes the pterygospinous process is directed from the posterior edge of the outer plate towards the spine of the sphenoid bone. processus pterygospinosus, which can reach the specified spine and form a hole.

Sphenoid bone, os sphenoidale, located in the center of the base of the skull.

Functions of the sphenoid bone

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.

Structure of the sphenoid bone

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 is a paired plate extending from each side of the body of the sphenoid bone with two roots. Between the latter there is the optic canal, 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 anteriorly there is a round opening, foramen rotundum, through which the second branch of the trigeminal nerve passes, in the middle of the wing there is an oval opening, foramen ovale, for the third branch of the trigeminal nerve. The foramen spinosum, foramen spinosum, is smaller in size and is located in the region of the posterior corner of the greater 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 brain surface, fades cerebralis, finger-like impressions, impressidnes digitatae, and arterial grooves, sulci arteriosi, are well defined. The orbital surface, fades orbitalis, is a quadrangular smooth plate; part of the lateral wall of the orbit. The maxillary surface, fades maxillaris, occupies a triangular-shaped area between the orbital surface at the top and the base of the pterygoid process at the bottom. On this surface, facing the pterygopalatine fossa, a round opening opens. The temporal surface, fades tempordlis, is the most extensive. The 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 origin 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 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, splina ossis sphenoidalis. The plates of the pterygoid process are distinguished: medial, lamina medlis, and lateral, lamina lateralis. The anterior plates are fused. Posteriorly, the plates of the pterygoid process diverge, forming the pterygoid fossa, fossa pterygoidea. Below, both plates are separated by a pterygoid notch, incisura pterygoidea. The medial plate of the pterygoid process is somewhat narrower and longer than the lateral one and below passes into the pterygoid hook, hamulus pterygoideus.

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

Body - inside contains the pneumatic sinus 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 sphenooccipital 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;

dorsum sella 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:

the anterior edge connecting to the frontal bone with a flat suture;

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;

the optic chiasm groove connecting the internal openings of the optic canals.

Large wings: right and left.

At the base of the wing, closer to the sella turcica, there are three openings sequentially from front to back: round for the second branch of the 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 in a hook;

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

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 palatine bone with its perpendicular plate participate in its formation. 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 of the sphenoid bone with the canal of the same name, which passes the autonomic pterygoid nerve and vessels of the same name into the fossa from the area of ​​the foramen lacerum.

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 the middle cranial fossa through the foramen rotundum, through which the maxillary branch of the trigeminal nerve passes;

with the area of ​​the lacerated foramen 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 the 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 blood to the upper jaw, teeth and gums, lower eyelid, lacrimal sac and eye muscles, 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 veins of the parotid salivary gland, middle meningeal, tympanic, inferior ophthalmic and deep facial veins flow into the pterygoid venous plexus.

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 greater 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 subaponeurotic is located under the temporal aponeurosis, the deep - under the temporal muscle.

Infratemporal fossa

This is a downward continuation of the temporal fossa.

superior border: infratemporal crest and superior margin 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: inner surface of the ascending rami of the mandible;

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

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

Sphenoid bone, os sphenoidale, unpaired, resembles a flying insect, which explains the name of its parts (wings, pterygoid processes).

The sphenoid bone is the product of the fusion of several bones that independently exist in animals, therefore it develops as a mixed bone from several paired and unpaired ossification points, forming 3 parts at the time of birth, which in turn fuse into a single bone by the end of the first year of life.

It has the following parts:

1) body, corpus;

2) big arms, alae majores;

3) small wings,alae minores;

4)pterygoid processes, processus pterygoidei(its medial plate is the former double pterygoid, develops on the basis of connective tissue, while all other parts of the bone arise on the basis of cartilage).

Sphenoid bone. Back view. 1. Visual channel; 2. Saddle back; 3. Posterior inclined process; 4. Anterior inclined process; 5. Small wing; 6. Superior orbital fissure; 7. Parietal angle; 8. Large wing (cerebral surface); 9. Round hole; 10. Pterygoid canal; 11. Scaphoid fossa; 12. Lateral plate (pterygoid process); 13. Pterygoid notch; 14. Groove of the pterygoid hook; 15. Vaginal process; 16. Wedge-shaped ridge; 17. Body of the sphenoid bone; 18. Medial plate (pterygoid process); 19. Wing-shaped hook; 20. Pterygoid fossa; 21. Groove of the internal carotid artery.

Body, corpus, on its upper surface has a depression along the midline - saddle turcica, sella turcica, at the bottom of which lies hole For pituitary gland, fossa hypophysialis.In front of it there is an elevation, tuberculum sellae, along which passes transversely sulcus chiasmatis for cross ( chiasma) optic nerves; at the ends sulcus chiasmatis visible visual channels, canales optici, through which the optic nerves pass from the cavity of the orbits to the cavity of the skull. Posteriorly, the sella turcica is limited by a bony plate, back of the saddle, dorsum sellae. On the lateral surface of the body there is a curved carotid sulcus, sulcus caroticus, trace of the internal carotid artery.

On the anterior surface of the body, which is part of the posterior wall of the nasal cavity, is visible crest, crista sphenoidalis, below entering between the wings of the opener. Christa sphenoidalis connects anteriorly with the perpendicular plate of the ethmoid bone. Irregularly shaped holes are visible on the sides of the ridge, aperturae sinus sphenoidalis, leading to air sinus, sinus sphenoidalis, which is placed in the body of the sphenoid bone and is divided partition, septum sinum sphenoidalium, in two halves. Through these openings the sinus communicates with the nasal cavity. In a newborn, the sinus is of very small size and only around the 7th year of life begins to grow rapidly.

Small wings, alae minores, are two flat triangular plates, which with two roots extend anteriorly laterally from the anterosuperior edge of the body of the sphenoid bone; between the roots of the small wings are the mentioned visual channels, canales optici. Between the lesser and greater wings there is the superior orbital fissure, fissura orbitalis superior, leading from the cranial cavity to the orbital cavity.

Big wings, alae majores, extend from the lateral surfaces of the body laterally and upward. Near the body, behind fissura orbitalis superior available round hole, foramen rotundum, leading anteriorly into the pterygopalatine fossa, caused by the passage of the second branch trigeminal nerve, n. trigemini. At the back, a large wing in the form of an acute angle protrudes between the scales and the pyramid of the temporal bone. There is a foramen spinosum, foramen spinosum, through which it passes a. meningea media. Much more is visible in front of him foramen ovale, foramen ovale, through which the third branch passes n.trigemini.

Large wings have four surfaces: brain,facies cerebralis, orbital,facies orbitalis, temporal, facies temporalis, And maxillary, facies maxillaris. The names of the surfaces indicate the areas of the skull where they face. The temporal surface is divided into the temporal and pterygoid parts by infratemporal crest, crista infritemporalis.

Pterygoid processes, processus pterygoidei extend vertically downward from the junction of the greater wings and the body of the sphenoid bone. Their base is pierced by a sagittal canal, canalis pterygoideus, - the place of passage of the named nerve and vessels. The anterior opening of the canal opens into the pterygopalatine fossa.

Each process consists of two plates - lamina medialis And lamina lateralis, between which a fossa, fossa pterygoidea, is formed at the back.

The medial plate is bent at the bottom crochet, hamulus pterygoideus, through which the tendon that begins on this plate is thrown m. tensor veli palatini(one of the muscles of the soft palate).

Sphenoid bone. Front view. 1. Aperture of the sphenoid sinus; 2. Saddle back; 3. Wedge-shaped shell; 4. Small wing; 5. Superior orbital fissure; 6. Zygomatic edge; 7. Infratemporal surface, 8. Spine of the sphenoid bone; 9. Pterygopalatine groove; 10. Lateral plate; 11. Wing-shaped hook; 12. Medial plate of the pterygoid process; 13. Vaginal process; 14. Wedge-shaped ridge; 15. Pterygoid notch; 16. Pterygoid canal; 17. Round hole; 18. Infratemporal crest; 19. Orbital surface of the greater wing; 20. Temporal surface of the greater wing.

Variants and anomalies

Failure of fusion of the anterior and posterior halves of the body of the sphenoid bone leads to the formation of a narrow, so-called craniopharyngeal canal, in the center of the sella turcica. The foramen ovale and foramen spinosum sometimes merge into one common foramen; the foramen spinosum may be absent.