Wedge-shaped shell Latin. Anatomy: Sphenoid bone. What is a sphenoid bone

) unpaired, forms the central section of the base of the skull.

The middle part of the sphenoid bone is the body, corpus, cubic in shape, has six surfaces. On the upper surface, facing the cranial cavity, there is a recess - the Turkish saddle, sella turcica, in the center of which is the pituitary fossa, fossa hypophysialis, (see Fig. ). It contains the pituitary gland hypophysis. The size of the fossa depends on the size of the pituitary gland. The border of the Turkish saddle in front is the tubercle of the saddle, tuberculum sellae. Behind it, on the lateral surface of the saddle, there is a non-permanent middle inclined process, processus clinoideus medius.

Anterior to the tubercle of the saddle there is a shallow transverse precross groove, Sulcus prechiasmatis. Behind it lies the optic chiasm, chiasma opticum. Laterally, the groove passes into the optic canal, canalis opticus. Ahead of the furrow is a smooth surface - a wedge-shaped elevation, jugum sphenoidale connecting the small wings of the sphenoid bone. The front crane of the upper surface of the body is notched, protrudes slightly forward and connects to the posterior edge of the ethmoid plate of the ethmoid bone, forming a sphenoid-ethmoid suture, sutura spheno-ethmoidalis. The rear border of the Turkish saddle is the back of the saddle, dorsum sellae, which ends on the right and left with a small posterior inclined process, processus clinoideus posterior.

On the sides of the saddle from back to front there is a carotid furrow, sulcus caroticus, (a trace of the internal carotid artery and the accompanying nerve plexus). At the posterior edge of the furrow, on its outer side, a pointed process protrudes - a wedge-shaped tongue, Lingula sphenoidalis.

The back surface of the back of the saddle passes into the upper surface of the basilar part of the occipital bone, forming a slope, clivus, (on it lie the bridge, the medulla oblongata, the basilar artery and its branches). The rear surface of the body is rough; through the cartilaginous layer, it connects to the anterior surface of the basilar part of the occipital bone and forms a wedge-occipital synchondrosis, synchondrosis spheno-occipitalis. As we age, cartilage is replaced by bone tissue and both bones fuse together.

The anterior surface of the body and part of the lower face into the nasal cavity. A wedge-shaped ridge protrudes in the middle of the anterior surface, Crista sphenoidalis, its anterior edge is adjacent to the perpendicular plate of the ethmoid bone. The lower process of the crest is pointed, extended downwards and forms a wedge-shaped beak, rostrum sphenoidale. The latter is connected to the opener wings, alae vomeris, forming the vomero-coracoid canal, canalis vomerorostratis, (see Fig. ) lying along the midline between the upper edge of the vomer and the wedge-shaped beak. Lateral to the ridge lie thin curved plates - wedge-shaped shells, conchae sphenoidales, (see Fig. ). The shells form the anterior and partly inferior walls of the sphenoid sinus, sinus sphenoidalis. Each shell has a small opening - the aperture of the sphenoid sinus, apertura sinus sphenoidalis. Outside of 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 sphenoid-ethmoid suture, sutura spheno-ethmoidalis, and the lower ones - with the orbital processes, processus orbitalis, palatine bone.

sphenoid sinus, sinus sphenoidalis, (see Fig. ) - a paired cavity, which occupies most of the body of the sphenoid bone; it belongs to the air-bearing paranasal sinuses. The right and left sinuses are separated from one another by the septum of the sphenoid sinuses, septum sinuum sphenoidium, which anteriorly continues into the wedge-shaped ridge. As in the frontal sinuses, the septum is often asymmetrical, as a result of which the size of the sinuses may not be the same. Through the aperture of the sphenoid sinus, each sphenoid sinus communicates with the nasal cavity. The cavity of the sphenoid sinus is lined with a mucous membrane.

small wings, alae minores, sphenoid bone extend in both directions from the anteroposterior corners of the body in the form of two horizontal plates, at the base of which there is a rounded hole. From this hole begins a bone canal up to 5-6 mm long - the visual canal, canalis opticus. It contains the optic nerve n. opticus, and the ophthalmic artery, a. ophthalmica. Small wings have an upper surface facing the cranial cavity, and a lower surface directed into the cavity of the orbit and closing the upper orbital fissure from above, fissura orbitalis superior.

The anterior margin of the lesser wing, thickened and serrated, is connected to the orbital part of the frontal bone. The posterior edge, concave and smooth, protrudes freely into the cranial cavity and is the boundary between the anterior and middle cranial fossae, fossae cranii anterior et media, (see Fig. , ). Medially, the posterior margin ends with a protruding, well-defined anterior inclined process, processus clinoideus anterior, (a part of the dura mater is attached to it - the diaphragm of the Turkish saddle, diaphragma sellae).

Big wings, alae majores, depart from the lateral surfaces of the body of the sphenoid bone and go outward.

The large wing has five surfaces and three edges.

superior cerebral surface, facies cerebralis, concave, turned into the cranial cavity. It forms the anterior part of the middle cranial fossa. Finger-like impressions stand out on it, impressiones digitatae, [gyrorum]), and arterial sulci, sulci arteriosi, (imprints of the relief of the adjacent surface of the brain and middle meningeal arteries).

There are three permanent holes at the base of the wing: a round hole is located inward and anteriorly, foramen rotundum, (see fig. , ) (the maxillary nerve comes out through it, n maxillaris), outward and posterior to the round is an oval hole, foramen ovale, (it passes the mandibular nerve, n. mandibularis), and outside and behind the oval - a spinous opening, foramen spinosum, (through it come the middle meningeal artery, vein and nerve). In addition, non-permanent holes occur in this area. One of them is the vein foramen venosum located somewhat posterior to the foramen ovale. It passes the vein going from the cavernous sinus to the pterygoid venous plexus. The second is a rocky hole, foramen petrosum, through which the small stony nerve passes, is located behind the axillary foramen, closer to the axis of the sphenoid bone.

Anteriosuperior orbital surface, facies orbitalis, smooth, rhomboid, facing the cavity of the orbit and forming a large part of its outer wall. The lower edge of the surface is separated from the posterior edge of the orbital surface of the body of the upper jaw - here the lower orbital fissure is formed, fissura orbitalis inferior, (see Fig. , , ).

anterior maxillary surface, facies maxillaris, - a triangular area of ​​​​small length, limited from above by the orbital surface, from 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, (see fig. , ), it has a round hole.

superior temporal surface, facies temporalis, somewhat concave, takes part in the formation of the wall of the temporal fossa, fossa temporalis, (beams of the temporal muscle begin from it). From below, this surface is limited by the infratemporal crest, crista infratemporali, below the ridge there is a surface on which the oval and spinous openings open. It forms the upper wall of the infratemporal fossa (fossa infratemporalis), (here begins part of the lateral pterygoid muscle (m. pterygoideus lateralis).

upper frontal edge, margo frontalis, widely serrated, connects with the orbital part of the frontal bone, forming a wedge-frontal suture, sutura sphenofrontalis. The outer sections of the frontal edge end with a sharp parietal edge, margo parietalis, which with a wedge-shaped angle to the topic of another bone forms a wedge-parietal suture, sutura sphenoparietalis. The internal sections of the frontal margin pass into a thin free margin, which is separated from the lower surface of the lesser wing, limiting the superior orbital fissure from below.

anterior cheekbone, margo zygomaticus, jagged. frontal process, processus frontalis, zygomatic bone and zygomatic edge are connected, forming a sphenoid-zygomatic suture, sutura sphenozygomatica.

posterior scaly edge, margo squamosus, connects to the wedge-shaped edge, margo sphenoidalis, temporal bone and forms a wedge-squamous suture, sutura sphenosquamosa. Posteriorly and outwardly, the scaly edge ends with the spine of the sphenoid bone (the place of attachment of the sphenomandibular ligament, lig sphenomandibularis, and bundles of muscles that strain the palatine curtain, m. tensor veli palatini).

Inward from the spine of the sphenoid bone, the posterior edge of the large wing lies in front of the petrous part, pars petrosa, temporal bone and limits the sphenoid-stony fissure, fissura sphenopetrosa, medially passing into a torn hole, foramen la lacerum, (see Fig. , ), on a non-macerated skull, this gap is filled with cartilaginous tissue and forms wedge-stony synchondrosis, synchondrosis sphenopetrosa.

pterygoid processes (processus pterygoidei, (see Fig. , , ) depart from the junction of the large wings with the body of the sphenoid bone and go down. They are formed by two plates - lateral and medial. lateral plate, lamina lateralis, (processus pterygoidei), wider, thinner and shorter than the medial (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 lateral. Both plates grow together with their front edges and, diverging posteriorly, limit the pterygoid fossa, fossa pterygoidea, (here begins the medial pterygoid muscle, m. pterygoideus medialis). In the lower parts, both plates do not fuse and limit the pterygoid notch, incisura pterygoidea. It contains a pyramidal process processus pyramidalis, palatine bone. The free end of the medial plate ends with a pterygoid hook directed downward and outward, hamulus pterygoideus, on the outer surface of which there is a furrow of the pterygoid hook, sulcus hamuli pterygoidei, (the tendon of the muscle straining the palatine curtain is thrown through it, m. tensor veli palatini).

The posterior superior edge of the medial plate at the base expands and forms a navicular fossa with a wadded shape, fossa scaphoidea.

Outside of the scaphoid fossa is a shallow furrow of the auditory tube, sulcus tubae auditivae, (see Fig. ), which laterally passes to the lower surface of the posterior edge of the large wing and reaches the spine of the sphenoid bone (the cartilaginous part of the auditory tube is adjacent to this groove). Above the navicular fossa and medially there is an opening with which the pterygoid canal begins, 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 greater wing, on the posterior wall of the pterygopalatine fossa.

The medial plate at its base passes into 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, ala vomeris. At the same time, the groove of the vaginal process facing the wing of the vomer is the vomerovaginal groove, sulcus vomerovaginalis, turns into the vomerovaginal canal, canalis vomerovaginalis.

Outward from the process there is a sagittally running small palatovaginal groove, Sulcus palatovaginalis. The sphenoid process of the palatine bone adjacent from below, processus sphenoidalis ossis palatini, closes the furrow into the canal of the same name, canalis palatovaginalis, (see Fig. ) (in the vomerovaginal and palatine-vaginal canals, the nerve branches of the pterygopalatine node pass, and in the palatine-vaginal canal, in addition, the branches of the sphenoid-palatine artery).

Sometimes the pterygoid 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 awn and form a hole.

The anterior surface of the pterygoid process is connected to the posterior surface of the upper jaw in the region of the medial edge of the tubercle, forming the sphenoid-maxillary suture, sutura sphenomaxillaris, (see Fig.), which lies deep in the pterygo-palatine fossa.

Sphenoid bone, os sphenoidale , unpaired, forms the central section of the base of the skull.

The middle part of the sphenoid bone is the body, corpus, cubic in shape, has six surfaces. On the upper surface, facing the cranial cavity, there is a recess - the Turkish saddle, sella turcica, in the center of which is the pituitary fossa, fossa hypophysialis. It contains the pituitary gland, hypophysis. The size of the fossa depends on the size of the pituitary gland. The border of the Turkish saddle in front is the tubercle of the saddle, tuberculum sellae. Behind it, on the lateral surface of the saddle, there is an unstable middle inclined process, processus clinoideus medius.

Body of the sphenoid bone– corpus sphenoidalis

pituitary fossa-fossahypophysialis

saddle tubercle–tuberculumsellae

Posterior inclined processes processus clinoidei posterioris

Anterior inclined process–processus clinoideusanterior

Carotid furrow-sulcuscaroticum

wedge-shaped uvula– lingual sphenoidalis

wedge-shaped beak-rostrum sphenoidale

wedge-shaped shell-conchae sphenoidalis

Sphenoid sinus aperture– aperture sinus sphenoidalis

Sphenoid sinus– sinus sphenoidalis

small wing– ala minor

big wing–ala major

visual channel-canalis opticus

Superior orbital fissure– fissura orbitalis superior

round hole-foramen rotundum

oval hole–foramenovale

spinous foramen–foramenspinosus

cerebral surface-facies cerebralis

finger-like impressions–impressionsdigitales

arterial sulcus-sulcusarteriosi

Orbital surface–faciesorbitales

Maxillary surface–faciesmaxillaries

Temporal surface–faciestemporalis

Infratemporal ridge-cristainfratemporalis

pterygoid process–processuspterygoideus

pterygoid canal-canalispterygoideus

Sphenoid spine– spinaossis sphenoidalis

Medial plate–laminamedialis

Lateral plate–laminalateralis

pterygoid fossa–fossapterygoidea

Pterygoid notch–incisurapterygoidea

Pterygoid hook-hamulus pterygoideas

Body of the sphenoid bone

On the upper surface of the body there is a depression - the Turkish saddle, containing the pituitary gland. The anterior border of the saddle is the tubercle of the saddle, the posterior border is the back of the saddle. On the sides of the Turkish saddle are carotid grooves with cavernous sinuses, in which the internal carotid arteries and associated nerve plexuses pass. Anterior to the tubercle of the saddle is the chiasm furrow, on which the optic chiasm is located. The back of the saddle protrudes forward in the lateral sections, forming the posterior inclined processes. The back surface of the back of the Turkish saddle smoothly continues with the upper surface of the basilar part of the occipital bone, forming a slope.

In front, the body of the sphenoid bone is connected to the perpendicular plate of the ethmoid bone and the vomer through a vertically located wedge-shaped ridge. Posteriorly, the body of the sphenoid bone fuses with the basilar part of the occipital bone.

Most of the body of the sphenoid bone is made by the airy sphenoid sinus, divided by a septum into two halves. In front, the sinus is limited by wedge-shaped shells located on the sides of the wedge-shaped crest. The shells form holes - apertures through which the wedge-shaped cavity communicates with the nasal cavity. The walls of the sphenoid sinus are lined with a mucous membrane.

small wings

The lesser wings are directed away from the anteroposterior corners of the body in the form of two horizontal plates. At their base there are rounded holes, which are the beginning of the visual canals containing the optic nerves and ophthalmic arteries. The upper surfaces of the lesser wings face the cranial cavity, the lower surfaces face the cavity of the orbits, forming the upper walls of the upper orbital fissures. The front edges of the wings articulate with the orbital parts of the frontal bone. The posterior margins lie freely in the cranial cavity, being the border of the anterior and middle cranial fossae.

Small wings are connected to each other by a wedge-shaped elevation located in front of the decussation furrow.

Big wings

Large wings extend outward from the lateral surfaces of the body of the bone. The large wing has four surfaces and three edges. At the base of the large wing there are three openings: a round opening through which the maxillary nerve passes; oval, through which the mandibular nerve passes; spinous (it passes the middle meningeal artery, vein and nerve).

Large wing surfaces

The medulla, superior, faces the cranial cavity.

The orbital surface, anteroposterior, has a rhomboid shape. It is turned into the cavity of the orbit, forming part of its lateral wall. The lower edge of the orbital surface of the wing, along with the posterior edge of the orbital surface of the upper jaw, forms the inferior orbital fissure.

The maxillary surface, anterior, has a triangular shape, small size. From above it is limited by the orbital surface, from the side from below - by the root of the pterygoid process. The maxillary surface is involved in the formation of the posterior wall of the pterygopalatine fossa. It has a round hole.

The temporal surface, superior lateral, is divided by the infratemporal crest into the directly temporal and pterygoid surfaces. The temporal surface is involved in the formation of the temporal fossa. Oval and spinous openings open on the pterygoid surface. The pterygoid surface forms the anterior wall of the infratemporal fossa.

The edges of the big wing

The frontal edge, upper, is connected to the orbital part of the frontal bone by means of a wedge-frontal suture. The outer sections of the frontal edge end with a sharp parietal edge, forming a wedge-parietal suture with the parietal bone. The internal sections of the frontal margin pass into a thin free margin, which limits the superior orbital fissure from below.

The zygomatic edge, anterior, connects to the frontal process of the zygomatic bone, forming the sphenoid-zygomatic suture.

The scaly edge, posterior, connects with the sphenoid edge of the temporal bone and forms a wedge-squamous suture. Behind and outside, the scaly edge ends with the spine of the sphenoid bone. Inward from the spine, the scaly edge is located in front of the stony part of the temporal bone, forming with it a wedge-stony gap, passing medially into a torn hole.

pterygoid processes

Pterygoid processes (lat. processus pterygoidei) begin at the junction of the large wings with the body of the sphenoid bone and are located vertically downwards. At the base of the processes are pterygoid canals, in which the nerves and vessels of the same name pass. Anteriorly, each canal opens into the pterygopalatine fossa.

Each process consists of medial and lateral plates, which are fused in the anterior-upper sections, limiting the pterygoid fossa in front. The free, unfused ends of the plates limit the pterygoid notch filled with the pyramidal process of the palatine bone. The lower end of the medial plate ends with a pterygoid hook directed downward and outward.

The sphenoid bone (os sphenoidale) is unpaired, located in the center of the base of the skull, has four parts (Fig. 46).

46.A. Sphenoid bone (os sphenoidale), front view.
1 - corpus ossis sphenoidalis; 2 - dorsum sellae; 3 - ala minor; 4 - fissura orbitalis superior!; 5 - ala major; 6 - far. rotundum; 7 - canalis pterygoideus; 8 - processus pterygoideus

46.B. Sphenoid bone (posterior view).
1 - ala minor; 2 - ala major; 3 - facies orbitalis; 4 - facies temporalis; 5 - apertura sinus sphenoidalis; 6 - lamina lateralis; 7 - lamina medialis; 8 - processus pterygoideus.

The body (corpus) occupies a central position. The following formations are located on the upper surface of the body from front to back: sulcus chiasmatis, saddle tubercle (tuberculum sellae), Turkish saddle (sella turcica). In its center there is a hole in the location of the pituitary gland (fossa hypophysialis). Behind the pituitary fossa is the back of the Turkish saddle (dorsum sellae), which has the shape of a plate, on the upper edge of which there are two inclined posterior processes directed forward (processus clinoidei posteriores). On the sides of the body of the bone and the Turkish saddle there is an imprint from the pressure of the internal carotid artery (sulcus caroticus).

The anterior surface of the body of the sphenoid bone faces the nasal cavity. A wedge-shaped ridge (crista sphenoidalis) passes along its midline, connecting to the vomer. To the right and left of the ridge there are openings of the sphenoid sinus (aperturae sinus sphenoidalis), opening into paired air-bearing sinuses (sinus sphenoidales).

The large wing (ala major) is paired, departs laterally from the body of the bone. It has a cerebral surface facing upwards, an orbital surface facing forward, an inferior temporal surface that is visible from the outside, and a maxillary surface facing downwards. At the base of the large wing there is a round hole (for. rotundum); behind it is an oval hole (for. ovale) and then a smaller diameter spinous (for. spinosum).

The small wing (ala minor) is paired. Each in the form of a triangular plate starts from the side surfaces of the body. Closer to the midline, the anterior inclined process (processus clinoideus anterior), facing backwards, departs from the posterior edge of the small wing. At the base of the lesser wing is the optic canal (canalis opticus), in which the optic nerve and ophthalmic artery pass. Between the wings is the superior orbital fissure (fissura orbitalis superior).

The pterygoid process (processus pterygoideus) is paired, starting from the lower surface of the base of the large wing. At the beginning of the process, a pterygoid canal passes from front to back, connecting the torn hole (for. lacerum) with the pterygopalatine fossa. Each process has a lateral and medial plate (lamina lateralis et medialis). The latter bends below in the form of a pterygoid hook (hamulus pterygoideus); through it the tendon of the muscle straining the soft palate is thrown.

Ossification. At the 8th week of embryonic development, bone points appear in the cartilaginous rudiments of the large wings, which grow into the outer plates of the pterygoid processes. At the same time, ossification points are laid in the connective tissue medial plates. On the 9-10th week, bone rudiments appear in small wings. Three pairs of bone points are laid in the body, of which, at the 12th week of intrauterine development, two posterior ones are connected into one. Bone points are located in front and behind the Turkish saddle, grow together in the 10-13th year.

The sinus of the sphenoid bone in a newborn is represented by a protrusion of the mucous membrane of the nasal cavity with a depth of 2-3 mm, directed downward and backward. At the age of 4 years, the protrusion of the mucous membrane penetrates into the resorbed cavity of the cartilaginous body of the sphenoid bone, at 8-10 years old - into the body of the sphenoid bone to its middle, and by 12-15 years old it grows to the place of fusion of the body of the sphenoid and occipital bones (Fig. 47) .

47. Scheme of age-related changes in the volume of the airy sinus of the sphenoid bone (no Torigiani)

1 - superior nasal concha;
2 - middle turbinate;
3 - lower nasal concha;
4 - the border of the sinus in a newborn;
5 - at 3 years;
6 - at 5 years old;
7 - at 7 years old;
8 - at 12 years old;
9 - in an adult;
10 - Turkish saddle.

anomalies. Between the anterior and posterior parts of the body of the bone there may be a hole (the remainder of the canal that communicates the cranial cavity with the pharynx). A similar anomaly occurs as a result of nonunion of the anterior and posterior parts of the body of the bone. In animals, a cartilaginous layer is preserved for a long time between the anterior and posterior parts of the body of the bone.

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, large and small wings.

The 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 Turkish saddle (sella turcica) with a deep pituitary fossa (fossa hypophysialis). Behind in the Turkish saddle, the back of the saddle (dorsum sellae) is distinguished, and in front - the tubercle of the saddle (tuberculum sellae). On each side, the carotid groove (sulcus caroticus) is visible on the body of the bone - a trace of the fit of the internal carotid artery. On the anterior surface of the body of the sphenoid bone there is a wedge-shaped ridge (crista sphenoidalis). On the sides of the crest 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 that communicates with the nasal cavity.

The lateral surfaces of the body of the sphenoid bone directly pass into paired small and large wings.

The 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 edge is connected to the orbital part of the frontal bone and the ethmoid plate of the ethmoid bone. Between the small wing at the top and the upper edge of the large wing is an elongated opening - the upper orbital fissure (fissura orbitalis superior), connecting the cranial cavity with the orbit.

The large wing (ala major) starts from the lateral surface of the body of the sphenoid bone with a wide base and, like the small wing, is directed to the lateral side. It has four surfaces: cerebral, orbital, temporal and maxillary. The concave cerebral surface faces the cranial cavity. It has three openings through which blood vessels and nerves pass. A round hole (foramen rotundum), located closer to the base of the large wing, leads to the pterygopalatine fossa. At the level of the middle of the wing there is an oval hole (foramen ovale), which opens at the base of the skull, and behind it is a small spinous hole (foramen spinosum). The orbital surface (facies orbitalis) is smooth, participates in the formation of the lateral wall of the orbit. On the temporal surface (facies temporalis) passes the infratemporal ridge (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 pterygo-palatine fossa.

The pterygoid process (processus pterygoideus) is paired, departs downward from the body of the sphenoid bone. As part of the process, the medial and lateral plates (lamina medialis et lamina lateralis) are distinguished. Behind between the plates is the 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 on the whole skull with the region of the torn foramen.

Occipital bone (os occipitale) is located in the posterior part of the cerebral part of the skull. In this bone, the basilar part, two lateral parts and the occipital scales are distinguished, which surround the large (occipital) foramen (foramen magnum).

The basilar part (pars basilaris) is located in front of the large (occipital) foramen. In front, it connects to the body of the sphenoid bone, together with which it forms a platform - the 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).

The lateral part (pars lateralis) is steam room, behind it passes into the scales of the occipital bone. Below, on each lateral part, there is an elliptical elevation - the occipital condyle (condylus occipitalis), at the base of which is the hypoglossal nerve canal (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). To the side of the occipital condyle is the jugular notch (incisura jugularis), which, together with the jugular notch of the temporal bone pyramid, forms the jugular foramen. Next to the jugular notch on the cerebral surface is the groove of the sigmoid sinus (sulcus sinus sigmoidei).

Occipital scales (squama occipitalis) - a wide, outwardly convex plate, the edges of which are strongly serrated. On the whole skull, they are connected to the parietal and temporal bones. In the center of the outer surface of the scales, an external occipital protrusion (protuberantia occipitalis externa) is visible, from which a weakly expressed upper convex line (linea nuchae superior) departs on both sides. Down from the protrusion to the large (occipital) foramen passes the external occipital crest (crista occipitalis externa). From its middle to the right and to the left there is a lower line (hinea nuchae inferior). Above the external occipital protrusion, the highest you can sometimes see another line (linea nuchae suprema).

On the inner side of the occipital scales there is a cruciform elevation (eminentia cruciformis), dividing the cerebral 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 to the left of this protrusion is the groove of the transverse sinus (sulcus sinus transversus). Up from the protrusion is the groove of the superior sagittal sinus (sulcus sinus sagittalis superioris), and down to the large (occipital) foramen is the internal occipital crest (crista occipitalis interna).

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 recess in its middle sections - the Turkish saddle, 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 case of premature birth. The fusion of the two nuclei of ossification of the fossa occurs on the 8th month of intrauterine life. Hence, there is a possibility of damage to the structure of the pituitary fossa with subsequent dysfunction of the pituitary gland. The Turkish saddle is limited in front by the tubercle of the saddle, tuberculum sellae. Behind it, on the lateral surface of the saddle, there is a non-permanent middle inclined process, processus clinoideus medius. Anterior to the tubercle of the saddle there is a shallow transverse furrow of the decussation, sulcus chiasmatis. On it lies the optic chiasm, chiasma opticum. On the sides, the furrow passes into the optic canal, canalis opticus. Ahead of the furrow is a smooth surface - a wedge-shaped elevation, 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 wedge-ethmoid suture, sutura sphenoethmoidalis. The perforated plate has a large number of holes (25-30), through which branches of the anterior ethmoidal (olfactory) nerve and the vein accompanying the anterior ethmoidal artery pass from the nasal cavity into 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 trauma to the frontal bone, there may be a violation of the ratio in the wedge-lattice suture, followed by traumatization of the olfactory bulbs.

The Turkish saddle is bounded 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 Turkish saddle, from back to front, there is a carotid furrow, sulcus caroticus(an imprint of the internal carotid artery lying here and the nerve plexus accompanying it).

Rice. Sphenoid bone (according to H. Feneis, 1994): 1 - body; 2 - wedge-shaped elevation; 3 - large wing, 4 - small wing; 5 - precross furrow; 6 - Turkish saddle; 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 - cerebral 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 - spinous opening; 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 back surface of the back of the saddle passes into the upper surface of the basilar part of the occipital bone, forming a slope, clivus. On the slope are the bridge, the medulla oblongata, the basilar artery with its branches. The posterior surface of the body is rough. Through the 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 last anatomical term has taken root and is most common among osteopaths. It is believed that by the age of 25, cartilage is replaced by bone tissue and both bones fuse. However, there is still no consensus on this issue. Probably, the bones are still not fully fused.

The front and part of the lower surface of the body face the nasal cavity. In the middle of the anterior surface of the body, a vertically running wedge-shaped ridge protrudes, 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 opener wings, 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 inferior walls of the sphenoid sinus, sinus sphenoidalis, has a small opening - the aperture of the sphenoid sinus, apertura sinus sphenoidalis. Outside of 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 sphenoid-ethmoid suture, sutura sphenoethmoidalis, and the lower ones - with the orbital process, processus orbitalis, palatine bone.

sphenoid sinus, sinus sphenoidalis, a steam cavity, performs 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 continues anteriorly 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 a mucous membrane.

small wings, alae minores, sphenoid bone with two roots depart in both directions from the anterior-upper 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 the bone canal up to 5-6 mm long - the visual canal, canalis opticus. It contains the optic nerve n. opticus, and the ophthalmic artery, a. ophthalmica. Small wings have an upper surface facing the cranial cavity, and a lower surface directed into the cavity of the orbit and closing the upper orbital fissure from above, fissura orbitalis superior. The anterior margin of the lesser wing, thickened and serrated, is connected 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. Medially, the posterior edge ends with a protruding, well-defined, anterior inclined process, processus clinoideus anterior(part of the dura mater is attached to it, forming the diaphragm of the Turkish saddle, diaphragma sellae).

Large wings of the sphenoid bone, alae majores, depart from the lateral surfaces of the body of the sphenoid bone and are oriented outwards. The large wing has five surfaces and three edges. superior cerebral surface, facies cerebralis, concave and turned into the cranial cavity. It forms the anterior part of the middle cranial fossa and bears sulcular depressions, cerebral eminences and arterial sulci, sulci arteriosi(imprints of the relief of the adjacent surface of the brain and middle meningeal arteries). There are three holes at the base of the large wing: a round hole is located inward and anteriorly, foramen rotundum(the maxillary nerve exits through it, n. maxillaris). Outside and behind the round is an oval hole, foramen ovale (it passes the mandibular nerve, n. mandibularis, and the vasculature of the foramen ovale). Still outside and posterior to the foramen ovale is the spinous foramen, foramen spinosum(through it pass the middle meningeal artery, vein and nerve). Antero-superior, orbital surface, facies orbitalis, smooth, diamond-shaped, turned into the cavity of the orbit, where it forms most of its outer wall. The lower edge of this surface is separated from the posterior edge of the orbital surface of the body of the upper jaw; here the inferior orbital fissure is formed, fissura orbitalis inferior. Anterior, maxillary surface, facies maxillaris, a small area of ​​triangular shape, bounded above by the orbital surface, and from 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. Upper lateral, 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). From below, this surface is bounded by the infratemporal crest, crista infratemporalis, below which the surface is located, where the oval hole opens, foramen ovale, and a spinous foramen. It forms the superior wall of the infratemporal fossa fossa infratemporalis. Here begins part of the lateral pterygoid muscle, m. pterygoideus lateralis. The upper, frontal, edge is widely serrated, connects with 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 a wedge-parietal suture ( sutura sphenoparietalis). The internal sections of the frontal margin pass into a thin free margin, which is separated from the lower surface of the lesser wing, limiting the upper orbital fissure from below fissura orbitalis superior. Anterior, zygomatic edge, margo zygomaticus, serrated, connects with the frontal process, processus frontalis, zygomatic bone, forming a wedge-zygomatic suture ( sutura sphenozygomatica). Back, scaly edge, margo squamosus, connects to the wedge-shaped edge, margo sphenoidalis, temporal bone in the sphenoid-squamous suture ( sutura sphenosquamosa). Posteriorly and outwards, the scaly edge ends with the spine of the sphenoid bone, spina ossis sphenoidalis. Here is the site of attachment of the sphenomandibular ligament, lig. sphenomandibular, and bundles of muscles that strain the palatine curtain, m. tensor veli palatini. Inward from the spine of the sphenoid bone, the posterior edge of the large wing lies in front of the petrous part, pars petrosa, temporal bone and limits the sphenoid-stony fissure, fissura sphenopetrosa, medially passing into a torn hole, foramen lacerum. This gap is filled with cartilaginous tissue, forming wedge-stony synchondrosis, synchondrosis sphenopetrosa.

pterygoid processes, processus pterygoidei, depart from the junction of the large wings with the body of the sphenoid bone and go down. 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. Both plates grow together with their front 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 pyramidal process, processus pyramidalis, palatine bone. The free end of the inner plate ends with a pterygoid hook directed downward and outward, hamulus pterygoideus, on the outer surface of which there is a furrow of the pterygoid hook, sulcus hamuli pterygoidei(the tendon of the muscle straining the palatine curtain is thrown through it, m. tensor veli palatini). The posterior-upper edge of the inner plate at the base expands and forms an oblong navicular fossa, fossa scaphoidea(bunches of muscles begin in it, straining the palatine curtain, m. tensor veli palatini). Outside of the scaphoid fossa is a shallow furrow of the auditory tube, sulcus tubae audilivae, which laterally passes to the large 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 greater wing of the sphenoid bone on the posterior wall of the pterygopalatine fossa. Under the outlet, along the anterior face of the pterygoid process, there is a pterygopalatine groove. The inner plate at its base gives off a flat, horizontally running vaginal process directed inwards, processus vaginalis, which is located under the body of the sphenoid bone, covering the wing of the vomer from the side. 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 sagittally running small palatovaginal groove, Sulcus palatovaginalis. In the latter case, the sphenoid process of the palatine bone adjacent from below closes the groove into the canal of the same name (the nerve branches of the pterygopalatine ganglion pass through both canals, and the branches of the sphenoid-palatine artery also pass through the palatovaginal canal). Sometimes, from the posterior edge of the outer plate, the pterygoid process is directed towards the spine of the sphenoid bone. processus pterygospinosus, which can reach the specified awn and form a hole.