Superior sagittal sinus. Sinuses of the dura mater

This article is about venous sinuses and blood flow through them. I will try to reproduce the explanation, after which I myself began to understand them a little, being a listener.

Rice. Volumetric reconstruction of the venous sinuses of the hard meninges.

The volumetric course of these venous channels is difficult to project onto any one plane. Let's approach the sines from several projections. Let's start from the base of the skull from the cavernous sinuses.

The main tributaries of the cavernous sinus are:

veins of the orbit,
sphenoparietal sinus,
superficial middle veins of the brain.

Outflow of venous blood from the cavernous sinus:

superior petrosal sinus,
inferior petrosal sinus,
pterygoid plexus.

The sinus is paired and is located at the base of the skull on the sides of the sella turcica. The sinus contains many connective tissue septa that divide the sinus cavity into a number of separate interconnected cavities, like the corpus cavernosum.

Rice. View from above. The cavernous sinus is marked with blue dots.

Rice.Side view. The cavernous sinus is marked in blue in the bottom picture. FR - foramen rotundum, CC - foramen lacerum, Se - sella turcica, SOF - superior foramen lacerum, ICA - carotid artery (its cavernous segment).

Rice. Front view. The figure shows a frontal section through the cavernous sinus ( of blue color). The cavernous part of the internal cavity passes through the sinus carotid artery, or arteria carotis interna (red) and the surrounding sympathetic fibers. In addition, cranial nerves pass through the walls of the sinus ( yellow color): oculomotor nerve, trochlear nerve, orbital nerve (first branch trigeminal nerve), maxillary nerve (second branch of the trigeminal nerve), abducens nerve.

Rice. In the frontal plane, the cavernous sinus projects into the area between the orbits.

Main tributaries of the cavernous sinus.

Rivers through which venous blood fills the lake of the cavernous sinus.

Superior and inferior ophthalmic veins

There are two orbital veins: superior and inferior. Superior ophthalmic vein, v. ophthalmica superior leaves the orbit through superior orbital fissure into the cranial cavity, where it flows into the cavernous sinus. The inferior ophthalmic vein anastomoses with the superior ophthalmic vein and divides into two branches. The superior branch passes through the superior orbital fissure into the cranial cavity and joins the cavernous sinus.

Rice. The orbital veins drain into the cavernous sinus.

The inferior branch leaves the orbit through the inferior orbital fissure and enters the deep vein of the face, v. faciei profunda.

Rice. The superior and inferior ophthalmic veins drain into the cavernous sinus.

The sinus descends along the cranial vault along the coronal suture and passes under the sphenoparietal suture. Next, the sinus passes from the cranial vault to the free edge of the lesser wings sphenoid bone, follows them in the medial direction until it flows into the cavernous sinus.

Rice. The sphenoparietal sinuses are shown by arrows.

Superficial middle veins of the brain.

The middle (Sylvian) veins drain into the cavernous and sphenoparietal sinuses. The middle veins provide drainage from the anterior superior sections temporal lobes and posterior parts of the inferior frontal gyri.

Rice. The diagram shows the superficial venous system of the cerebral hemispheres (according to Bailey). The middle cerebral vein, which flows into the cavernous sinus, is marked in blue.
1 - vein of Trolard; 2 - veins of the Rolandic groove; 3 - Labbe vein; 4 - middle cerebral vein; 5 - anastomosis between the branches of the frontal veins and the branches of the middle cerebral vein.

Pterygoid plexus

The venous pterygoid plexus is located between the pterygoid muscles.
The cavernous sinus is connected by a series of anastomoses with the venous pterygoid plexus. The outflow of venous blood from the cranial cavity into the pterygoid plexus occurs through anastomoses passing through the lacerated, oval and Vesalian (if present) foramina of the base of the skull.

Rice. In the center of the picture at the top is the cavernous sinus. Its relationship with the pterygoid plexus is visible.

The middle meningeal veins are such anastomoses that carry venous blood from the cranial cavity to the outside. So, vv. meningeae mediae accompany the artery of the same name, connect along the way with the sphenoid-parietal sinus and, leaving the cranial cavity through the foramen spinosum, flow into the pterygoid (venous) plexus.

Rice. The pterygoid plexus is the venous network in the center of the picture. The plexus is connected to the deep facial vein (Fac) and the maxillary vein (Max), which in turn drain into the internal jugular vein.

In addition to connections with the cranial cavity, blood flows into the pterygoid plexus from the nasal cavity through the sphenopalatine vein, from temporal fossa along the deep temporal veins, from the masticatory muscles along the masticatory veins.

Intercavernous sinus

The right and left cavernous sinuses are connected to each other by two transverse anastomoses: the anterior and posterior intercavernous, or intercavernous sinuses, or sinus intercavernosi.

Rice. Anterior and posterior intercavernous, or intercavernous sinuses, orsinus intercavernosi are located between the cavernous sinuses.

Due to this, a closed ring of venous cavities is formed around the sella turcica.

Rice. The photograph of the specimen shows the anterior (SICS) and posterior (IICS) intercavernous sinuses, flanked by the carotid arteries.

The outflow of blood from the cavernous sinuses occurs in the dorsal direction along the superior and inferior petrosal sinuses.

The superior petrosal sinuses originate in the posterior part of the cavernous sinus and pass along the upper edge of the pyramid temporal bone and empty into the sigmoid sinus.

Rice. The superior petrosal sinuses are marked with arrows. They start from the cavernous sinus (marked with blue dots), pass along the upper edge of the pyramid of the temporal bone and flow into the sigmoid sinus.

Rice. The lower stony sinuses run along the slope back and down (marked by arrows), flow into the internal jugular veins(marked with circles) of the corresponding side.

In the posterior cranial fossa, the foramen magnum is surrounded by a venous ring, similar to the venous rings of the spinal canal. This unpaired plexus, called the main one, connects in front with the cavernous sinuses, and on the sides with the lower stony sinuses. In addition to the connections described, the main plexus also communicates with the venous plexuses of the spinal canal and through the occipital sinus with the transverse sinus.

This concludes the first part about sines.

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Table of contents of the topic "Internal base of the skull. Blood supply to the brain. Venous drainage from the brain.":

Direct sine, sinus rectus, is located at the junction of the falx cerebri and the tentorium cerebellum and runs in the sagittal direction. The great cerebral vein, v., also flows into it. cerebri magna, collecting blood from the substance of the cerebrum. The straight sinus, like the superior sagittal sinus, flows into the sinus drainage.

Occipital sinus, sinus occipitalis, passes at the base of the falx cerebellum, falx cerebelli. Its upper end flows into the sinus drain, and the lower end at the foramen magnum divides into two branches that go around the edges of the foramen and flow into the left and right sigmoid sinuses. The occipital sinus is connected through emissary veins to the superficial veins of the cranial vault.

Thus, in sine drain venous blood comes from the superior sagittal sinus, direct (and through it from the inferior sagittal sinus) and occipital sinuses. From the confluens sinuum, blood flows into the transverse sinuses.

Transverse sinus, sinus transversus, lies at the base of the tentorium of the cerebellum. On the inner surface of the squama of the occipital bone it corresponds to a wide and clearly visible groove of the transverse sinus. On the right and left, the transverse sinus continues into the sigmoid sinus of the corresponding side.

Sigmoid sinus, sinus sigmoideus, receives venous blood from the transverse and is directed to the anterior part of the jugular foramen, where it passes into the superior bulb of the internal jugular vein, bulbus superior v. jugularis internae. The course of the sinus corresponds to the groove of the same name on the inner surface of the base of the mastoid process of the temporal and occipital bones. Through the mastoid emissary veins, the sigmoid sinus is also connected to the superficial veins of the cranial vault.

In doubles cavernous sinus, sinus cavernosus, located on the sides of the sella turcica, blood flows from the small sinuses of the anterior cranial fossa and the veins of the orbit. The ophthalmic veins flow into it, vv. ophthalmicae, anastomosing with the veins of the face and with the deep pterygoid venous plexus of the face, plexus pterygoideus. The latter is also connected to the cavernous sinus through emissaries. The right and left sinuses are connected by intercavernous sinuses - sinus intercavernosus anterior et posterior.

Blood flows from the cavernous sinus through the superior and inferior petrosal sinuses into the sigmoid sinus and then into the internal jugular vein.

Cavernous sinus connection with superficial and deep veins and with the dura mater of the brain has great importance in dissemination inflammatory processes and explains the development of such severe complications as meningitis.

Through the cavernous sinus pass through the internal carotid artery, a. carotis interna, and abducens nerve, n. abducens (VI pair); through its outer wall - the oculomotor nerve, p. oculomotorius (III pair), trochlear nerve, p. trochlearis (IV pair), as well as the I branch of the trigeminal nerve - the ophthalmic nerve, n. ophthalmicus (Fig. 5.12).

To the rear cavernous sinus adjacent gasserian node trigeminal nerve - ganglion trigeminal. TO anterior section cavernous sinus is sometimes suitable fatty tissue the pterygopalatine fossa, which is a continuation of the fatty body of the cheek.

Thus, venous blood from all parts of the brain through the cerebral veins enters one or another dural sinus and then into the internal jugular vein. When increasing intracranial pressure blood from the cranial cavity can additionally be discharged into the system of superficial veins through emissary veins. Reverse blood flow is possible only as a result of thrombosis of the superficial vein associated with the emissary vein developing for one reason or another.

We also recommend a video of the anatomy and topography of the dural sinuses

Other video lessons on this topic are located: "".

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 are ensured by the presence large quantity collagen and elastin fibers. This membrane is loosely connected to the bones of the roof of the skull, and with the base of the skull it has fusions at the exit points of the nerves, along the edges of the openings, etc. At the points of attachment to the bones, the membrane splits and forms canals - venous sinuses: upper and lower sagittal, straight, transverse, sigmoid, cavernous, wedge-shaped, superior and inferior petrosal, etc. Sinuses do not have valves, this allows venous blood to flow freely from the brain. In a number of places, the dura mater forms processes that protrude into the cracks between in separate parts brain. So it forms the falx cerebri between the hemispheres. Above the cerebellum, in the form of a gable tent, is the tentorium of the cerebellum, the anterior edge of which has a notch for the brain stem. The cerebellar falx is located between the cerebellar hemispheres, and the diaphragm is stretched above the sella turcica, in the center of which there is an opening for the pituitary infundibulum.

ARACNOUS TUNER (arachnoidea) - thin, transparent, does not extend into grooves and crevices, separated from the soft membrane by the subarachnoidalis, which contains cerebrospinal fluid. In the area of deep grooves and cracks, the subarachnoid space is expanded and forms cisterns. The largest among them: cerebellocerebral (between the cerebellum and medulla oblongata); cistern of the lateral fossa (in the lateral sulcus of the hemispheres); intersection tank (in front of the intersection optic nerves); interpeduncular (in the interpeduncular fossa). Cerebrospinal fluid (CSF) is produced by the choroid plexuses of the ventricles and circulates throughout all ventricles and subarachnoid spaces of the brain and spinal cord. The outflow of cerebrospinal fluid into the venous bed occurs through granulations formed by protrusion arachnoid membrane into the venous sinuses.

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

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

1. Superior sagittal sinus (sinus sagittalis superior) -- unpaired, passes along midline of the cranial vault in the groove of the same name from the cock's crest, where they flow into the sinus veins of the nasal cavity, to the internal occipital protuberance, 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 flow.
2. Inferior sagittal sinus (sinus sagittalis inferior) - unpaired, located in the lower free edge of the falx cerebri. The veins of the medial surface of the hemispheres open into it. After connecting with the great cerebral vein, it passes into the straight sinus.
3. Direct sine (sinus rectus) - unpaired, stretches along the junction of the falx cerebellum and the tentorium cerebellum. The large cerebral vein opens into it in front, and the sinus connects with the transverse sinus behind.
4. Sine drain (confluence sinuum) - the junction of the superior sagittal and direct sinuses; located at the internal occipital protrusion.
5. Transverse sinus (sinus traversus) - paired, located in the posterior edge of the tentorium of the cerebellum, in the groove of the same name in the occipital bone. Anteriorly it becomes the sigmoid sinus. The occipital cerebral veins flow into it.
6. Sigmoid sinus (sinus sigmoideus) - paired, located in the groove of the same name on 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 falx of the cerebellum along the internal occipital crest, drains blood from the sinus drainage. At the posterior edge of the foramen magnum, the sinus bifurcates. Its branches surround the opening and flow into the terminal segments of the right and left sigmoid sinuses.

In the region of the clivus of the occipital bone, in the thickness of the dura mater lies basilar plexus (plexus basilaris). It connects with the occipital, inferior petrosal, cavernous sinuses and the internal venous vertebral plexus.

8. Cavernous sinus (sinus cavernosus) - paired, the most complex in structure, lies on the sides of the sella turcica. In its cavity there 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. Cavernous sinuses connected in front of him And posterior intercavernous sinuses (sinus intercavernosus anterior et posterior). They flow into the sinus upper And inferior ophthalmic veins, inferior veins brain. When the cavernous part of the internal carotid artery is damaged, anatomical conditions are created for the formation of arteriovenous carotid-cavernous aneurysms (pulsatile exophthalmos syndrome).
9. Sphenoparietal sinus (sinus sphenoparietalis) lies along the edges of the lesser wings of the sphenoid bone. Opens into the cavernous sinus.
10. Superior and inferior petrosal sinuses (sinus petrosi superior et 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. Flows 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 round venous plexus And oval holes - with the 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 calvarium; the sigmoid sinus is connected by the mastoid emissary vein to the veins of the back of the head; The transverse sinus has similar anastomoses with the occipital veins through the occipital emissary vein.

This article is about venous sinuses and blood flow through them. I will try to reproduce the explanation, after which I myself began to understand them a little, being a listener.

Rice. Volumetric reconstruction of the venous sinuses of the dura mater.

The main tributaries of the cavernous sinus are:

veins of the orbit,
sphenoparietal sinus,
superficial middle veins of the brain.

Outflow of venous blood from the cavernous sinus:

superior petrosal sinus,
inferior petrosal sinus,
pterygoid plexus.

Rice. View from above. The cavernous sinus is marked with blue dots.

Rice. Front view. The picture shows a frontal section through the cavernous sinus (blue). The cavernous part of the internal carotid artery, or arteria carotis interna (red) and the surrounding sympathetic fibers pass through the sinus. In addition, cranial nerves (yellow) pass through the walls of the sinus: oculomotor nerve, trochlear nerve, orbital nerve (first branch of the trigeminal nerve), maxillary nerve (second branch of the trigeminal nerve), abducens nerve.

Rice. In the frontal plane, the cavernous sinus projects into the area between the orbits.

Main tributaries of the cavernous sinus.

Rivers through which venous blood fills the lake of the cavernous sinus.

Superior and inferior ophthalmic veins

Rice. The orbital veins drain into the cavernous sinus.

The inferior branch leaves the orbit through the inferior orbital fissure and enters the deep vein of the face, v. faciei profunda.

Rice. The superior and inferior ophthalmic veins drain into the cavernous sinus.

The sinus descends along the cranial vault along the coronal suture and passes under the sphenoparietal suture. Next, the sinus passes from the cranial vault to the free edge of the small wings of the sphenoid bone, following them in the medial direction until it flows into the cavernous sinus.

Rice. The sphenoparietal sinuses are shown by arrows.

Superficial middle veins of the brain.

The middle (Sylvian) veins drain into the cavernous and sphenoparietal sinuses. The middle veins provide drainage from the anterior superior parts of the temporal lobes and the posterior parts of the inferior frontal gyri.

Pterygoid plexus

Rice. In the center of the picture at the top is the cavernous sinus. Its relationship with the pterygoid plexus is visible.

In addition to connections with the cranial cavity, blood flows into the pterygoid plexus from the nasal cavity through the sphenopalatine vein, from the temporal fossa through the deep temporal veins, and from the masticatory muscles through the masticatory veins.

Intercavernous sinus

The right and left cavernous sinuses are connected to each other by two transverse anastomoses: the anterior and posterior intercavernous, or intercavernous sinuses, or sinus intercavernosi.

Rice. Anterior and posterior intercavernous, or intercavernous sinuses, orsinus intercavernosi are located between the cavernous sinuses.

Due to this, a closed ring of venous cavities is formed around the sella turcica.

Rice. The photograph of the specimen shows the anterior (SICS) and posterior (IICS) intercavernous sinuses, flanked by the carotid arteries.

The outflow of blood from the cavernous sinuses occurs in the dorsal direction along the superior and inferior petrosal sinuses.

The superior petrosal sinuses originate in the posterior part of the cavernous sinus, pass along the upper edge of the pyramid of the temporal bone and empty into the sigmoid sinus.

Rice. The inferior stony sinuses run along the slope backwards and downwards (marked by arrows), flow into the internal jugular veins (marked by circles) of the corresponding side.

This concludes the first part about sines.

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This shell is particularly dense and contains a large number of collagen and elastic fibers. Dura shell the inside of the brain lines the cavities of the skull, and at the same time is the periosteum of the inner surface of the bones of the cerebral part of the skull. The hard shell of the brain is loosely connected to the bones of the vault (roof) of the skull and is easily separated from them. In the area of the base of the skull, the shell is firmly fused with the bones. The hard shell surrounds the cranial nerves emerging from the brain, forming their sheaths and fused with the edges of the openings through which these nerves leave the cranial cavity.

At the inner base of the skull (in the region of the medulla oblongata), the dura mater of the brain fuses with the edges of the foramen magnum and continues into the dura mater of the spinal cord. The inner surface of the dura mater, facing the brain (towards the arachnoid), is smooth, covered flat cells. In some places, the dura mater of the brain is split. Its inner leaf (duplication) is deeply indented in the form of processes into the cracks that separate parts of the brain from each other. In places where the processes arise (at their base), as well as in areas where the dura mater is attached to the bones of the internal base of the skull, in the splits of the dura mater of the brain, triangular-shaped channels lined with endothelium are formed - the sinuses of the dura mater (sinus durae matris)

The largest process of the dura mater of the brain is located in the sagittal plane and penetrating into the longitudinal fissure of the cerebrum between the right and left hemispheres of the falx cerebri, or large falx cerebri. This is a thin sickle-shaped plate of the dura mater, which penetrates in the form of two sheets into the longitudinal fissure of the cerebrum. Not reaching corpus callosum, this plate separates the right and left hemisphere big brain. In the split base of the falx cerebri, which in its direction corresponds to the groove of the superior sagittal sinus of the cranial vault, lies the superior sagittal sinus. In the thickness of the free edge of the falx cerebri, between its two layers there is the inferior sagittal sinus. In front, the falx cerebri is fused with the cock's crest of the ethmoid bone. The posterior part of the falx at the level of the internal occipital protrusion fuses with the tentorium of the cerebellum. Along the line of fusion of the posteroinferior edge of the falx cerebellum and the tentorium cerebellum, in the fissure of the dura mater of the brain, there is a straight sinus connecting the inferior sagittal sinus with the superior sagittal, transverse and occipital sinuses.

The tentorium of the cerebellum (tentorium cerebelli) hangs in the form of a gable tent over the posterior cranial fossa, in which the cerebellum lies. Penetrating into the transverse fissure, the tentorium cerebellum separates the occipital lobes of the cerebrum from the cerebellar hemispheres. The anterior margin of the tentorium cerebellum is uneven. It forms a notch of the tentorium (incisura tentorii), to which the brain stem is adjacent in front.

The lateral edges of the tentorium cerebellum are fused with the upper edge of the pyramids of the temporal bones. Posteriorly, the tentorium of the cerebellum passes into the dura mater of the brain, lining the inside of the occipital bone. At the site of this transition, the dura mater of the brain forms a split - the transverse sinus, adjacent to the groove of the same name in the occipital bone.

The cerebellar falx, or small falx cerebelli, like the falx cerebellum, is located in the sagittal plane. Its anterior edge is free and penetrates between the cerebellar hemispheres. The posterior edge (base) of the falx cerebellum continues to the right and left into the dura mater of the brain from the internal occipital protuberance above to the posterior edge of the foramen magnum below. The occipital sinus forms at the base of the falx cerebellum.

Diaphragm (Turkish) sella

(diaphragma sellae) is a horizontal plate with a hole in the center, stretched over the pituitary fossa and forming its roof. The pituitary gland is located in the fossa under the diaphragm of the sella. Through an opening in the diaphragm, the pituitary gland is connected to the hypothalamus using a funnel.

The sinuses (sinuses) of the dura mater of the brain, formed by splitting the shell into two plates, are channels through which venous blood flows from the brain into the internal jugular veins.

The sheets of hard shell that form the sinus are stretched tightly and do not collapse. Therefore, the sinuses gape on the cut. Sinuses do not have valves. This structure of the sinuses allows venous blood to flow freely from the brain, regardless of fluctuations in intracranial pressure. On the inner surfaces of the skull bones, in the locations of the sinuses of the dura mater, there are corresponding grooves. The following sinuses of the dura mater of the brain are distinguished.

The superior sagittal sinus (sinus sagittalis superior) is located along the entire outer (upper) edge of the falx cerebri, from the crest of the ethmoid bone to the internal occipital protuberance. In the anterior sections, this sinus has anastomoses with the veins of the nasal cavity. The posterior end of the sinus flows into the transverse sinus. To the right and left of the superior sagittal sinus there are lateral lacunae (lacunae laterales) communicating with it. These are small cavities between the outer and inner layers (sheets) of the dura mater of the brain, the number and size of which are very variable. The cavities of the lacunae communicate with the cavity of the superior sagittal sinus; the veins of the dura mater of the brain, the cerebral veins and the dyshuic veins flow into them.
The inferior sagittal sinus (sinus sagittalis inferior) is located in the thickness of the lower free edge of the falx cerebri. It is significantly smaller than the top one. With its posterior end, the inferior sagittal sinus flows into the straight sinus, into its anterior part, in the place where the lower edge of the falx cerebellum fuses with the anterior edge of the tentorium cerebellum
The straight sinus (sinus rectus) is located sagittally in the splitting of the tentorium cerebellum along the line of attachment of the falx cerebellum to it. The straight sinus connects the posterior ends of the superior and inferior sagittal sinuses. In addition to the inferior sagittal sinus, the great cerebral vein drains into the anterior end of the straight sinus. At the back, the straight sinus flows into the transverse sinus, into its middle part, called the sinus drainage. The posterior part of the superior sagittal sinus and the occipital sinus also flow here.
The transverse sinus (sinus transversus) lies at the point where the tentorium cerebellum departs from the dura mater of the brain. On the inner surface of the squama of the occipital bone, this sinus corresponds to a wide groove of the transverse sinus. The place where the superior sagittal, occipital and straight sinuses flow into it is called sinus drainage (confluens sinuum, confluence of sinuses). On the right and left, the transverse sinus continues into the sigmoid sinus of the corresponding side.
The occipital sinus (sinus occipitalis) lies at the base of the cerebellar falx. Descending along the internal occipital crest, this sinus reaches the posterior edge of the foramen magnum, where it divides into two branches, covering the back and sides of this foramen. Each of the branches of the occipital sinus flows into the sigmoid sinus on its side, and the upper end into the transverse sinus.
The sigmoid sinus (sinus sigmoideus) is paired, located in the groove of the same name on the inner surface of the skull, and has an S-shape. In the area of the jugular foramen, the sigmoid sinus passes into the internal jugular vein.
The cavernous sinus (sinus cavernosus) is paired, located at the base of the skull on the side of the sella turcica. The internal carotid artery and some cranial nerves pass through this sinus. Sine has a very complex design in the form of caves communicating with each other, which is why it got its name. Between the right and left cavernous sinuses there are communications (anastomoses) in the form of anterior and posterior intercavernous sinuses (sinus intercavernosi), which are located in the thickness of the diaphragm of the sella turcica, in front and behind the pituitary infundibulum. The sphenoparietal sinus and the superior ophthalmic vein flow into the anterior parts of the cavernous sinus.
The sphenoparietal sinus (sinus sphenoparietalis) is paired, adjacent to the free posterior edge of the lesser wing of the sphenoid bone, in the split it is attached here by the dura mater of the brain.
The superior and inferior petrosal sinuses (sinus petrosus superior et sinus petrosus inferior) are paired, located along the upper and lower edges of the pyramid of the temporal bone. Both sinuses take part in the formation of pathways for the outflow of venous blood from the cavernous sinus to the sigmoid sinus. The right and left inferior petrosal sinuses are connected by several veins lying in the cleft of the dura in the area of the body of the occipital bone, which are called the basilar plexus. This plexus connects through the foramen magnum to the internal vertebral venous plexus.

In some places, the sinuses of the dura mater of the brain form anastomoses with the external veins of the head using emissary veins - graduates (vv. emissariae). In addition, the sinuses of the dura mater have communications with diploic veins (vv. diploicae), located in the spongy substance of the bones of the calvarium and flowing into the superficial veins of the head. Thus, venous blood from the brain flows through the systems of its superficial and deep veins into the sinuses of the dura mater of the brain and further into the right and left internal jugular veins.

In addition, due to the anastomoses of the sinuses with diploic veins, venous graduates and venous plexuses (vertebral, basilar, suboccipital, pterygoid, etc.), venous blood from the brain can flow into the superficial veins of the head and neck.

Vessels and nerves of the dura mater of the brain

Approaches the dura mater of the brain through the right and left spinous foramina middle meningeal artery(branch of the maxillary artery), which branches in the temporo-parietal part of the membrane. The dura mater of the brain lining the anterior cranial fossa is supplied with blood by branches anterior meningeal artery(branch of the anterior ethmoidal artery from the ophthalmic artery). In the shell of the posterior cranial fossa they branch posterior meningeal artery - a branch of the ascending pharyngeal artery from the external carotid artery, penetrating into the cranial cavity through the jugular foramen, as well as meningeal branches from vertebral artery And mastoid branch from the occipital artery, entering the cranial cavity through the mastoid foramen.

The veins of the pia mater of the brain drain into the nearest sinuses of the dura mater, as well as into the pterygoid venous plexus.

The dura mater of the brain is innervated by the branches of the trigeminal and vagus nerve, as well as due to sympathetic fibers entering the membrane in the thickness of the adventitia of blood vessels. In the area of the anterior cranial fossa it receives branches from optic nerve(first branch of the trigeminal nerve). The branch of this nerve is tentorial(shell) branch- also supplies the tentorium cerebellum and the falx cerebellum. The middle meningeal branch from the maxillary nerve, as well as a branch from the mandibular nerve (corresponding to the second and third branches of the trigeminal nerve), approach the shell in the middle medullary fossa.

Arachnoid membrane of the brain

The arachnoid membrane of the brain (arachnoidea mater encephali) is located medially from the dura mater of the brain. The thin, transparent arachnoid membrane, unlike the soft membrane (vascular), does not penetrate into the cracks between individual parts of the brain and into the sulci of the hemispheres. It covers the brain, moving from one part of the brain to another, and lies over the grooves. The arachnoid is separated from the soft membrane of the brain by the subarachnoid space (cavitas subaracnoidalis), which contains cerebrospinal fluid. In places where the arachnoid membrane is located above wide and deep grooves, the subarachnoid space is expanded and forms subarachnoid cisterns of greater or lesser size (cisternae subarachnoideae).

Above the convex parts of the brain and on the surface of the convolutions, the arachnoid and pia mater are tightly adjacent to each other. In such areas, the subarachnoid space narrows significantly, turning into a capillary gap.

The largest subarachnoid cisterns are the following.

The cerebellar cistern (cisterna cerebellomedullaris) is located in the recess between the medulla oblongata ventrally and the cerebellum dorsally. At the back it is limited by the arachnoid membrane. This is the largest of all tanks.
The cistern of the lateral fossa of the cerebrum (cisterna fossae lateralis cerebri) is located on the inferolateral surface of the cerebral hemisphere in the fossa of the same name, which corresponds to the anterior sections of the lateral sulcus of the cerebral hemisphere.
The chiasm cistern (cisterna chiasmatis) is located at the base of the brain, anterior to the optic chiasm.
The interpeduncular cistern (cisterna interpeduncularis) is determined in the interpeduncular fossa between the cerebral peduncles, downward (anterior) from the posterior perforated substance.

The subarachnoid space of the brain in the region of the foramen magnum communicates with the subarachnoid space of the spinal cord.

Cerebrospinal fluid

Cerebrospinal fluid (liquor cerebrospinalis), formed in the ventricles of the brain, is poor in protein substances and lacks cells. Total this liquid is 100-200 ml. It is produced by the choroid plexuses of the lateral, III and IV ventricles from their blood capillaries. The walls of blood capillaries, the basement membrane, and the epithelial lamina covering the capillaries form the so-called blood-brain barrier. This barrier of blood in the cavity of the ventricles selectively allows some substances to pass through and retains others, which is an important circumstance for protecting the brain from harmful influences.

From the lateral ventricles through the right and left interventricular (Monroys) openings, cerebrospinal fluid enters the third ventricle, where there is also a choroid plexus. From the third ventricle, through the cerebral aqueduct, cerebrospinal fluid enters the fourth ventricle and then through the foramen azygos into the back wall (Magendie hole) and paired lateral aperture (Lushka hole) flows into the cerebellocerebral cistern of the subarachnoid space.

The arachnoid membrane is connected to the soft membrane lying on the surface of the brain by numerous thin bundles of collagen and elastic fibers, between which blood vessels pass. Near the sinuses of the dura mater of the brain, the arachnoid membrane forms peculiar outgrowths, protrusions - granulations of the arachnoid membrane (granulationes arachnoideae; Pachionian granulations). These protrusions protrude into the venous sinuses and lateral lacunae of the dura mater. On the inner surface of the skull bones, at the location of the granulations of the arachnoid membrane, there are depressions - dimples of granulations, where the outflow of cerebrospinal fluid into the venous bed occurs.

Soft (vascular) membrane of the brain (pia mater encephali)

This is the most inner shell brain. She fits tightly to outer surface brain and enters all the cracks and grooves. The soft shell consists of loose connective tissue, in the thickness of which there are blood vessels leading to the brain and feeding it. In certain places, the soft membrane penetrates the cavities of the ventricles of the brain and forms the choroid plexus (plexus choroideus), which produces cerebrospinal fluid.

Age-related features of the membranes of the brain and spinal cord

The dura mater of the brain in a newborn is thin, tightly fused with the bones of the skull. The processes of the shell are poorly developed. The sinuses of the dura mater of the brain are thin-walled and relatively wide. The length of the superior sagittal sinus in a newborn is 18-20 cm. The sinuses are projected differently than in an adult. For example, the sigmoid sinus is located 15 mm posterior to the external tympanic ring. ear canal. There is a greater asymmetry in the size of the sinuses than in an adult. The anterior end of the superior sagittal sinus anastomoses with the veins of the nasal mucosa. After 10 years, the structure and topography of the sinuses are the same as in an adult.

The arachnoid and soft membranes of the brain and spinal cord in a newborn are thin and delicate. The subarachnoid space is relatively large. Its capacity is about 20 cm 3, and increases quite quickly: by the end of the 1st year of life up to 30 cm 3, by 5 years - up to 40-60 cm 3. In children 8 years old, the volume of the subarachnoid space reaches 100-140 cm 3, in an adult it is 100-200 cm 3. The cerebellocerebral, interpeduncular and other cisterns at the base of the brain in a newborn are quite large. Thus, the height of the cerebellocerebral cistern is approximately 2 cm, and its width (at upper limit) - from 0.8 to 1.8 cm.

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