Sinuses of the dura mater. Cavity and hollow formations. Features of the cerebral sinuses

The brain, like the spinal cord, is surrounded by three membranes. The outermost is hard, the middle is arachnoid and the inner is soft (vascular).

SOLID (dura mater), its strength and elasticity is ensured by the presence of a large number of collagen and elastin fibers. this shell is not firmly connected with the bones of the roof of the skull, and has adhesions to the base of the skull at the exit points of the nerves, along the edges of the holes, etc. At the places of attachment to the bones, the shell splits and forms channels - venous sinuses: upper and lower sagittal, straight, transverse, sigmoid, cavernous, wedge-shaped, superior and inferior stony, etc. The sinuses do not have valves, which allows venous blood to flow freely from the brain. In a number of places, the dura mater forms processes that protrude into the gaps between the individual parts of the brain. So it forms a sickle of the brain between the hemispheres. Above the cerebellum in the form of a gable tent is a cerebellar mantle, the front edge of which has a notch for the brain stem. Between the hemispheres of the cerebellum is the sickle of the cerebellum, and a diaphragm is stretched over the Turkish saddle, in the center of which there is an opening for the pituitary funnel.

Arachnoid membrane (arachnoidea) - thin, transparent, does not enter the furrows and crevices, separated from the soft shell by the subarachnoid space (subarachnoidalis), which contains cerebrospinal fluid. In the area of ​​deep furrows and fissures, the subarachnoid space is expanded and forms cisterns. The largest among them are: cerebellar-cerebral (between the cerebellum and the medulla oblongata); cistern of the lateral fossa (in the lateral groove of the hemispheres); cistern of chiasm (anterior to optic chiasm); interpeduncular (in the interpeduncular fossa). Cerebrospinal fluid (CSF) is produced by the choroid plexuses of the ventricles and circulates through all the ventricles and subarachnoid spaces of the brain and spinal cord. The outflow of cerebrospinal fluid into the venous bed is carried out through granulations formed by the protrusion of the arachnoid membrane into the venous sinuses.

SOFT SHELL (pia mater) consists of loose connective tissue, in the thickness of which there are blood vessels that feed the brain. This membrane is tightly attached to the surface of the brain and enters all the furrows, fissures and ventricles. In the ventricles, it forms the choroid plexuses that produce cerebrospinal fluid.

Sinuses of the dura mater (sinus dura matris). The sinuses are channels formed by the splitting of the dura mater, usually at its attachment to the bones of the skull. The walls of the sinuses are covered with endothelium from the inside, dense, do not collapse, which ensures free blood flow.

• 1. superior sagittal sinus (sinus sagittalis superior) - unpaired, runs along the midline of the cranial vault in the eponymous groove from the cockscomb, where they flow into the sinus veins of the nasal cavity, to the internal occipital prominence where the superior sagittal sinus joins the transverse sinus. The lateral walls of the sinus have numerous openings connecting its lumen with lateral lacunae (lacunae laterales) into which the superficial cerebral veins drain.
• 2. inferior sagittal sinus (sinus sagittalis inferior) - unpaired, located in the lower free edge of the falx cerebrum. The veins of the medial surface of the hemispheres open into it. After connecting with the great cerebral vein, it passes into the direct sinus.
• 3. Direct sine (sinus rectus) - unpaired, stretches along the junction of the sickle of the cerebrum and the cerebellum. In front, a large cerebral vein opens into it, from behind, the sinus connects to the transverse sinus.
• 4. sinus drain (confluens sinuum) - the junction of the superior sagittal and direct sinuses; located at the internal occipital protrusion.
• 5. transverse sinus (sinus transversus) - paired, located in the posterior edge of the cerebellum, in the occipital bone groove of the same name. In front passes into the sigmoid sinus. The occipital cerebral veins flow into it.
• 6. Sigmoid sinus (sinus sigmoideus) - paired, located in the same groove of the occipital bone and opens into the superior bulb of the internal jugular vein. The temporal cerebral veins drain into the sinus
• 7. Occipital sinus (sinus occipitalis) - unpaired, small, lies in the crescent of the cerebellum along the internal occipital crest, drains blood from the sinus drain. At the posterior edge of the foramen magnum, the sinus bifurcates. Its branches surround the opening and flow into the final segments of the right and left sigmoid sinuses.

In the region of the clivus of the occipital bone, in the thickness of the dura lies basilar plexus. It connects to the occipital, inferior stony, cavernous sinuses and the internal venous vertebral plexus.

• 8. Cavernous sinus (sinus cavernosus) - double, the most complex in structure, lies on the sides of the Turkish saddle. In its cavity is the internal carotid artery, and in the outer wall - the first branch of the V pair of cranial nerves, III, IV, VI cranial nerves. The cavernous sinuses are connected in front of him and posterior intercavernous sinuses (sinus intercavernosus anterior and posterior). Fall into the sinus upper and inferior ophthalmic vein, inferior veins of the brain. When the cavernous part of the internal carotid artery is damaged, anatomical conditions are created for the formation of arteriovenous carotid-cavernous aneurysms (pulsating exophthalmos syndrome).
• 9. Sphenoparietal sinus (sinus sphenoparietalis) lies along the edges of the small wings of the sphenoid bone. Opens into the cavernous sinus.
• 10. Superior and inferior petrosal sinuses (sinus petrosi superior and inferior) - paired, lie along the edges of the pyramid of the temporal bone along the grooves of the same name, they connect the sigmoid and cavernous sinuses. Falls into them superficial middle cerebral vein.Venous sinuses have numerous anastomoses, through which a roundabout outflow of blood from the cranial cavity is possible, bypassing the internal jugular vein: the cavernous sinus through venous plexus of the carotid canal surrounding the internal carotid artery, connected to the veins of the neck, through venous plexus round and oval holes- with pterygoid venous plexus, and through ophthalmic veins- with facial veins. The superior sagittal sinus has numerous anastomoses with the parietal emissary vein, diploic veins, and veins of the cranial vault; the sigmoid sinus is connected by the mastoid emissary vein to the veins of the occiput; the transverse sinus has similar anastomoses with the occipital veins via the occipital emissary vein.

Sinuses of the dura mater of the brain , sinus durae matris, are channels in the clefts of the dura mater, lined with endothelium, through which venous blood flows from the brain, orbit and eyeball, inner ear, skull bones and meninges. From the sinuses, it enters the internal jugular vein, which originates in the region of the jugular foramen of the skull. In addition, the sinuses are involved in the exchange of cerebrospinal fluid. In their structure, they differ significantly from veins; they are triangular in cross section. When cut, the sinuses do not subside, there are no valves in their lumen. This structure contributes to the free outflow of blood from the brain, regardless of fluctuations in intracranial pressure. Major venous sinuses:

1. The superior sagittal sinus, sinus sagittalis superior, unpaired, is formed along the sulcus sinus sagittalis superioris of the cranial vault in the upper edge of the falx cerebrum. The sinus starts from the blind foramen of the frontal bone and reaches the internal protrusion of the occipital bone, where it flows into the sinus drain. Superficial veins of the cerebral hemispheres, veins of the dura mater of the brain and diploic veins flow into the superior sagittal sinus.

2. The lower sagittal sinus, sinus sagittalis inferior, unpaired, is a splitting of the lower edge of the sickle of the brain. It starts in front of the corpus callosum and ends at the junction of the great cerebral vein of Galen and the direct sinus.

3. The direct sinus, sinus rectus, unpaired, is located in the splitting of the cerebellar plaque along the line of attachment of the crescent cerebrum to it. It receives the great cerebral vein and the inferior sagittal sinus. It flows into the confluence of the transverse and superior sagittal sinuses. This place is called the sinus drain, confluens sinuum.

4. The transverse sinus, sinus transversus, is located in the frontal plane in the same groove of the occipital bone. It extends from the sinus drain to the sigmoid groove, where it continues into the sigmoid sinus of the corresponding side.

5. The sigmoid sinus, sinus sigmoideus, paired, is located in the groove of the same name on the inner surfaces of the parietal, temporal and occipital bones, being a continuation of the transverse sinus. It ends at the jugular foramen at the base of the skull, where it passes into the internal jugular vein.

6. The occipital sinus, sinus occipitalis, not paired, is located at the base of the sickle of the cerebellum. Starts from sinus drain , confluens sinuum, runs parallel to the internal occipital crest, reaches a large occipital foramen, which covers the back and sides. It flows into the sigmoid sinus of the corresponding side, connects with the internal venous vertebral plexuses.

7 . Pe cavernous sinus, sinus cavernosus, paired, located on the base of the skull, on the sides of the Turkish saddle. Through this sinus passes the internal carotid artery and the abducens nerve, and in its lateral wall - the oculomotor, trochlear and ophthalmic nerves. The pulsation of the internal carotid artery in the cavernous sinus contributes to the outflow of blood from its individual receptacles (caverns), since the walls of the sinus are not very pliable. The sphenoparietal sinus flows into the anterior part of the sinus.

8. The anterior and posterior intercavernous sinuses, sinus intercavernosi anterior et posterior, are located in front and behind the Turkish saddle in the splitting of the diaphragma sellae. They connect the right and left cavernous sinuses, receive the superior ophthalmic vein and blood from the basilar plexus, plexus basilaris, which is located on the clivus of the skull. This plexus connects the posterior intercavernous sinus, the inferior petrosal sinus, and the internal vertebral venous plexuses, forming a second pathway for the outflow of venous blood from the cranial cavity through the vertebral veins.

9. The sphenoparietal sinus, sinus sphenoparietalis, paired, is located on the posterior edge of the small wings of the sphenoid bone and connects to the sinus cavernosus.

10. Superior petrosal sinus, sinus petrosus superior, paired, corresponds to the groove of the superior petrosal sinus of the pyramid of the temporal bone, connects the cavernous and sigmoid sinuses.

11. The lower stony sinus, sinus petrosus inferior, paired, corresponds to the groove of the lower stony sinus, has a larger clearance than the upper stony sinus. It connects with the intercavernous sinus and the basilar plexus.

Rice. 2.18. Venous sinuses of the dura mater of the brain and their relationship with vv.diploicae and external veins of the head (diagram).

1 – vv. diploicae; 2 - sinus sagittalis superior; 3 - sinus transversus et confluens sinuum; 4 - sinus sigmoideus; 5-v. occipitalis; 6-v. jugularis interna; 7-v. facialis; 8 - v.angularis; 9 - sinus cavernosus; 10-v. temporalis superficialis.

II. Diploic veins of the bones of the cranial vault.

diploic veins, vv. diploicae, are found in the spongy substance of the bones of the cranial vault. Through the veins of graduates vv. emissariae, they flow into the superficial veins of the head and anastomose with the sinuses of the dura mater, providing a connection between the systems of the internal and external jugular veins. There are no valves in diploic veins, so blood flow through them is possible in two directions.

The main diploic veins are located in the scales of the bones of the same name, these are:

1. Frontal diploic vein, v. diploica frontalis;

2. Temporal diploic veins, v.v. diploicae temporale;

3. Occipital diploic vein, v.diploica occipitalis.

The sinuses of the dura matris (sinus durae matris) function as veins and are also involved in the exchange of cerebrospinal fluid. In their structure, they differ significantly from veins. The inner surface of the sinuses is lined with endothelium, which is located on the connective tissue basis of the dura mater. In the region of the furrows of the inner surface of the skull, the dura mater bifurcates and attaches to the bones along the edges of the furrows. On the transverse section, the sinuses have a triangular shape (Fig. 509). When cut, they do not collapse, there are no valves in their lumen.

Venous blood from the brain, orbit and eyeball, inner ear, skull bones, meninges enters the venous sinuses. The venous blood of all sinuses mainly flows into the internal jugular vein, which originates in the region of the jugular foramen of the skull.

Distinguish the following venous sinuses (Fig. 416).
1. The superior sagittal sinus (sinus sagittalis superior) is unpaired, formed on the outer edge of the falciform outgrowth of the dura mater and the sagittal groove. The sine starts from for. cecum and along the sulcus sagittalis of the cranial vault reaches the internal eminence of the occipital bone. The veins of the hemispheres of the brain and skull bones flow into the superior sagittal sinus.

2. The lower sagittal sinus (sinus sagittalis inferior) is single, located on the lower edge of the crescent of the dura mater. It starts in front of the corpus callosum and ends at the junction of the great vein of the brain and the rectus sinus. This place is located in the transverse groove of the brain near the quadrigemina, where the falx cerebrum and the dura mater of the cerebellum converge.

3. The direct sinus (sinus rectus) is unpaired, located at the junction of the falciform process and the cerebellum tenon. It receives the large cerebral vein and the inferior sagittal sinus. It ends at the confluence of the transverse and superior sagittal sinuses, called the drain of the sinuses (confluens sinuum).

4. The transverse sinus (sinus transversus) is paired, located in the frontal plane in the same groove of the occipital bone. It extends from the internal eminence of the occipital bone to the sigmoid groove of the temporal bone.

5. The sigmoid sinus (sinus sigmoideus) begins at the posterior lower angle of the parietal bone and ends at the jugular foramen at the base of the skull.

6. The occipital sinus (sinus occipitalis) is often paired, located in the falciform process of the cerebellum, connects the drain of the sinuses (confluens sinuum), runs parallel to the internal occipital crest, reaching the occipital foramen, where it connects to the sigmoid sinus, the internal jugular vein and the internal venous plexus of the spinal column .

7. Cavernous sinus (sinus cavernosus) is paired, located on the sides of the Turkish saddle. The internal carotid artery passes through this sinus, and in its outer wall - the oculomotor, trochlear, abducent and ophthalmic nerves. The pulsation of the internal carotid artery in the cavernous sinus contributes to the ejection of blood from it, since the walls of the sinus are not very pliable.

8. Intercavernous sinus (sinus intercavernosus) is paired, located in front and behind the Turkish saddle. It connects the cavernous sinuses and receives the veins of the orbit and blood from the basilar plexus (plexus basilaris), which is located on the slope of the skull and connects the posterior intercavernous sinus, the inferior petrosal sinus, and the internal vertebral venous plexus.

9. The superior petrosal sinus (sinus petrosus superior) connects the cavernous and sigmoid sinuses. It is located on the upper stony groove of the pyramid of the temporal bone.
10. The lower stony sinus (sinus petrosus inferior) is paired, establishes an anastomosis between the cavernous sinus and the bulb of the internal jugular vein. This sinus corresponds to the inferior petrosal sulcus and is larger in diameter than the superior petrosal sinus.
11. The sphenoid sinus (sinus clinoideus) is located on the posterior edge of the small wings of the sphenoid bone and connects to the sinus cavernosus.
12. Sinus drain (confluens sinuum) - expansion of the sinuses at the junction of the transverse, superior longitudinal, occipital and direct sinuses. This extension is located on the internal occipital eminence.

In medicine, the term sinus durae matris - sinuses of the dura mater, implies vascular collectors located between the plates of the dura mater. These are peculiar triangular ducts with endothelium on the surface, formed in the splittings of the hard layer of the brain. They are provided with blood from the internal and superficial vessels of the brain, participate in the reabsorption of the cerebrospinal fluid substance from the cavity between the arachnoid and nondura mater.

Sine functions

There are certain tasks for the venous sinuses. They perform the function of an uninterrupted supply of blood and oxygen to the vessels of the brain. It is through them that the blood flows directly from the head organ to several double veins located on the neck, which carry the blood away from the upper body.

The sinuses of the dura mater carry out the functions of blood vessels, and in addition take part in the metabolism of the cerebrospinal fluid. The structure is very different from the cerebral vessels.

Successful leakage of blood from the cerebral vessels often saves from the occurrence of fatal pathologies. In cases where there are difficulties in the field of vascular circulation, it becomes possible to quickly eliminate it, due to recanalization of blood vessels and the formation of collaterals.

The structure of the sinuses of solid MO

The development of TMF reservoirs is due to their division into two sheets that look like channels. These ducts are designed to distribute the venous blood flow from the main human organ, which is subsequently sent to several double vessels that are located on the neck and transfer blood from the brain.

The DM plates that make up the sinus look like tightly stretched ropes that do not lose tension. This structure allows blood to flow freely from the head and neck, in no way touching the state of intracranial pressure.

In humans, the following types of TMT reservoirs are installed:

1. superior or inferior sagittal. The first one is located along the upper border of the falciform bone and ends on a fragment of the occiput, and the next one is longitudinally the border of the sickle below and flows into the straight sinus;
2. Straight. It is placed longitudinally of the fragment, where the falciform process passes into the cerebellar mantle;
3. Cross (double). Formed on a transverse growth of the skull, being longitudinally the posterior border of the cerebellar groove;
4. Occipital. It is located in the cavity of the cerebellar arch, and then spreads to the occipital junction;
5. Sigmoid. It is located in the division in the ventral fragment of the head bone tissue;
6. Cavernous (double). It is located on the sides of the formation in the body of a bone in the form of a wedge ();
7. Sphenoparietal sinus (double). Refers to a small border of bone in the form of a wedge and ends in a cavernous reservoir.

Stony (double). Located close to both borders of the pyramidal bone of the temples.

The collectors of the medulla begin to collect fistulas with venous vessels on the surface of the brain, through venous branches that unite the vascular sinuses of the DM with the external blood circulation vessels of the head. These depressions begin to communicate with the diploic processes, which are characterized by placement in the cranial vault and then pass into the vessels of the head. Then the blood tends to pass through the venous plexuses and then flows into the DM reservoirs.

Types of sinuses TMO

Nature very thoughtfully created a person, providing the dura mater with recesses to provide the main organ with oxygen and nutrient compounds.

superior sagittal sinus

This cranial sinus is characterized by a large space with a complex structure. The crescent of the main human organ takes a significant part in its development. This is a crescent leaf. It is made from the dura mater. The process originates from the top of the ethmoid bone, passes in the middle back, penetrating into the interhemispheric foramen that separates the parts of the brain from each other. A striated outgrowth of the superior sagittal sinus, essentially the base of the falciform bone.

This duct provides numerous gaps on the sides. These are small cavities that are connected with a venous network of strong plates.

The superior sagittal reservoir has the following venous connections:

• the anterior parts belong to the vessels of the labial cavity (near the nose);
• the middle parts belong to the venous channels of the parietal fragments of the brain.

This collector of arteries and veins, as a person grows, becomes larger and wider in terms of mass capacity. Its posterior fragment protrudes into the united sinus drain.

Inferior sagittal sinus

This cistern of the structure of the cranium is presented in medical annals as sinus sagittalis inferior. It was so named for the reason that it is located in the lower location of the cerebral arch. Compared to the upper reservoir, it has a significantly smaller volume. Due to the large number of venous fistulas, it is attached to the direct.

Direct sine

This fragment of the cranium is, in fact, the so-called continuation of the lower cistern from the back. It combines the rear sections of the superior tanks and the lower manifold. Along with the upper, a large vessel is included in the anterior part of the non-dual sinus. The posterior part of the cavity flows into the median fragment of the double descending duct, which developed due to the divergence of the dura mater of the cranium, which is located in the furrow of the hard tissue of the occiput, continues laterally and towards the bottom, is attached to the sinus. This fragment is called sinus drain.

Sigmoid venous sinus

This reservoir is the most significant and extensive. On the surface inside the scales of the occipital bone tissue, it is presented in an extensive furrow. The venous reservoir then flows into the sigmoid sinus. Further, it deepens into the mouth of the most extensive vessel, which performs venous leakage from the head. So the transverse sinus and sigmoid sinus are characterized as the main venous reservoirs. In addition, all other pockets go to the first one. Some sinuses of the veins are directly included in it, some - through a smooth transition. On the temporal sides, the transverse pocket continues with a sigmoid deepening of the proper side. The place where the venous extensions of the sagittal, direct and occipital sinuses are included in it is called the common drain.

cave reservoir

It got this name because it has a large number of partitions. They provide the tank with an appropriate structure. Through the cavernous sinus, the abducent, ophthalmic, block, nerve fibers that move the eyes, and in addition the carotid artery (which is inside) are stretched along with the sympathetic interlacing (vegetative nerves in the thoracic-lumbar region). There are communicative connections between the right and left localizations of space. They are provided in the posterior and anterior intercavernous. Accordingly, a venous ring develops in the location of the Turkish saddle. In the cavernous sinus (in its flank fragments) it passes into the space of the sphenoid-parietal sinus, which lies on the border of a small branch of the bone in the form of a wedge.

Occipital venous sinus

The occipital cistern is located at the base of the arch and the upper part of the occipital region located inside. From above, it refers to the transverse duct. In the lower part, this pocket is divided into two branches, which encircle the joint at the back of the head. They are interconnected by sigmoid sinuses on both sides. The superficial veins of the main human organ and the veins and vessels of the spine are related to the occipital space.

Structural violations

Pathologies of these vascular plexuses occur due to their blockage, which in turn is provoked by thrombosis, thrombophlebitis, or a compressive neoplasm of intracranial veins and arteries.

Inflammation of the structures of the main human organ can appear when pathogens penetrate into the bloodstream (all kinds of unbound vascular substrate solid, liquid or vaporous, circulating through the bloodstream, uncharacteristic in the normal state, capable of provoking blockage of the artery at a fairly large distance from the site of occurrence). A pathological agent can get on the meninges and blood vessels of the head bone tissue on its surface . In this case, the appearance of symptoms of peak manifestation, and other pathologies, is likely. In preschool children, a picture of neuropoisoning is manifested.

In some cases, damage to the base of the skull can be established by neurosurgeons, seeing signs of intense exophthalmos. A fracture disrupts the integrity of the internal carotid artery in contact with the cavernous duct. The flow of venous blood, penetrating into the eye veins related to this reservoir, provokes pulsation, obvious hyperemia and protrusion of the apple of the visual organ. This deviation is otherwise called the carotid-cavernous anastomosis, and this is one of the extremely rare pathologies when listening to the skull with a phonendoscope makes it possible to hear blood flow noises in the area of ​​​​combination of vessels.

The main recommendation of doctors is the timely appeal to a specialist for clarification of the picture and the nature of symptomatic manifestations. As well as the prevention of mechanical head injuries and protection from external factors, such as, for example, weather conditions.

Prevention of brain diseases is possible only if you visit a doctor and get rid of chronic diseases, in particular those that are associated with an increase in the viscosity of hemostasis or stratification of the walls of blood vessels. In addition, it is necessary to treat infectious pathologies in a timely manner, it is they who for the most part become the cause of deviations.

Sinuses of the dura mater, sinus durae matris , are a kind of venous vessels, the walls of which are formed by sheets of the hard shell of the brain.

Common to the sinuses and venous vessels is that both the inner surface of the veins and the inner surface of the sinuses are lined with endothelium.

The difference lies primarily in the structure of the walls. The wall of the veins is elastic, consists of three layers, their lumen collapses when cut, while the walls of the sinuses are tightly stretched, formed by dense fibrous connective tissue with an admixture of elastic fibers, the lumen of the sinuses gapes when cut.

In addition, the venous vessels have valves, and in the cavity of the sinuses there is a number of fibrous crossbars covered with endothelium and incomplete septa, which are thrown from one wall to another and reach significant development in some sinuses. The walls of the sinuses, unlike the walls of the veins, do not contain muscle elements.

1. Superior sagittal sinus, sinus sagittalis superior, has a triangular lumen and runs along the upper edge of the falx cerebrum (a process of the hard shell of the brain) from the cockscomb to the internal occipital protrusion. It flows most often into the right transverse sinus, sinus transversus dexter. Along the course of the superior sagittal sinus, small diverticula extend - lateral lacunae, lacunae laterales.

2.Inferior sagittal sinus, sunus sagittalis inferior, stretches along the entire lower edge of the falx cerebrum. At the lower edge of the crescent joins the direct sinus, sinus rectus.

3. Direct sinus, sinus rectus, located along the junction of the falx cerebrum with the cerebellum. Has the shape of a quadrangle. Formed by sheets of the dura mater of the cerebellum. The direct sinus is directed from the posterior edge of the inferior sagittal sinus to the internal occipital protuberance, where it flows into the transverse sinus, sinus transversus.

4. transverse sinus, sinus transversus, paired, lies in the transverse groove of the bones of the skull along the posterior edge of the cerebellum tenon. From the area of ​​​​the internal occipital protrusion, where both sinuses are widely communicated with each other, they are directed outward, to the area of ​​\u200b\u200bthe mastoid angle of the parietal bone. Here each of them passes into the sigmoid sinus, sinus sigmoideus, which is located in the groove of the sigmoid sinus of the temporal bone and through the jugular opening passes into the superior bulb of the internal jugular vein.

5.Occipital sinus, sinus occipitalis, passes in the thickness of the edge of the falx cerebellum along the internal occipital crest, from the internal occipital protrusion to the foramen magnum. Here it splits into marginal sinuses, which bypass the large occipital foramen to the left and right and flow into the sigmoid sinus, less often directly into the superior bulb of the internal jugular vein.

Sinus drain, confluens sinuum, is located in the region of the internal occipital protrusion. Only in a third of cases the following sinuses are connected here: both sinus transversus, sinus sagittalis superior, sinus rectus.

6. Cavernous sinus, sinus cavernosus, paired, lies on the lateral surfaces of the body of the sphenoid bone. Its lumen has the shape of an irregular triangle.

The name of the sinus "cavernous" is due to the large number of connective tissue partitions that permeate its cavity. The internal carotid artery lies in the cavity of the cavernous sinus, a. carotis interna, with the sympathetic plexus surrounding it, and the abducens nerve, n. abducens.

In the outer upper wall of the sinus pass the oculomotor nerve, n. oculomotorius, and blocky, n. trochlearis; in the outer side wall - the ophthalmic nerve, n. ophthalmicus (first branch of the trigeminal nerve).

7. Intercavernous sinuses, sinus intercavernosi, located around the Turkish saddle and pituitary gland. These sinuses connect both cavernous sinuses and together form a closed venous ring.

8.Sphenoparietal sinus, sinus sphenoparietalis, paired, located along the small wings of the sphenoid bone; flows into the cavernous sinus.

9. Superior stony sinus, sinus petrosus superior, paired, lies in the upper stony groove of the temporal bone and goes from the cavernous sinus, reaching the sigmoid sinus with its posterior edge.

10. Lower stony sinus, sinus petrosus inferior, paired, lies in the lower stony groove of the occipital and temporal bones. The sinus runs from the posterior margin of the cavernous sinus to the superior bulb of the internal jugular vein.

11. Basilar plexus, plexus basilaris, lies in the region of the clivus of the sphenoid and occipital bones. It has the appearance of a network that connects both cavernous sinuses and both lower stony sinuses, and below it connects to the internal vertebral venous plexus, plexus venosus vertebralis internus.

The sinuses of the dura mater receive the following veins: veins of the orbit and the eyeball, veins of the inner ear, diploic veins and veins of the dura mater, veins of the cerebrum and cerebellum.