Falciform process of the dura mater. Crescent cerebrum Crescent dura mater

Solid meninges(dura mater spinalis et encephali) (Fig. 510) lines the inner surface of the skull and spinal canal.

The hard shell consists of two layers - outer and inner. In the skull, it performs the function of the periosteum and in most of it easily exfoliates from the bones. It is firmly attached to the bone along the edges of the openings of the base of the skull, on the crista galli, on the posterior edge of the lesser wings. sphenoid bone, on the edges of the Turkish saddle, on the body of the sphenoid and occipital bones (clivus) and on the surface of the pyramids of the temporal bone. In the outer layer of the dura mater, as well as in the furrows of the bone, nerves, arteries, and two veins accompanying the arterial trunk pass. The inner layer of the dura mater is smooth, shiny, and loosely connected to the arachnoid mater to form the subdural space.

The dura mater surrounding the spinal cord is a continuation of the dura mater brain. It starts from the edge of the foramen magnum and reaches the level of the III lumbar vertebra, where it ends blindly. hard shell spinal cord consists of dense outer and inner plates, consisting of collagen and elastic fibers. The outer plate makes up the periosteum and perichondrium of the spinal canal (endorachis). Between the outer and inner plates there is a layer of loose connective tissue - the epidural space (cavum epidurale), in which the venous plexuses are located. The inner plate of the hard shell is fixed on the spinal roots in the "intervertebral foramina. In the cranial cavity, the hard shell forms crescent-shaped processes in the cracks of the brain.
1. The crescent of the brain (falx cerebri) is a very elastic plate located vertically in the sagittal plane, penetrating into the gap between the cerebral hemispheres. In front, the sickle is attached to the blind foramen of the frontal bone and the cocks crest of the ethmoid bone, with a convex edge all along it is fused with the sagittal groove of the skull and ends at the internal occipital eminence (eminentia occipitalis interna) (see Fig. 510). The inner edge of the crescent of the brain is concave and thickened, as it contains the inferior sagittal sinus and hangs over the corpus callosum. The back part of the falx of the brain is fused with a transversely located process - the cerebellum tenon.

510. Internal base of the skull with cranial nerves.
1 - n. opticus; 2-a. carotis interna; 3 - n. oculomotorius; 4 - n. trochlearis; 5 - n. abducens; b - n. trigeminus; 7-n. facialis; 8-n. vestibulochlearis; 9-n. glossopharyngeus; 10-n. vagus; 11-n. hypoglossus; 12 - confluens sinuum; 13 - sinus transverse; 14 - sinus sigmoideus; 15 - sinus petrosus superior; 16 - sinus petrosus inferior; 17 - sinus intercavernousus; 18-tr. olfactorius; 19 - bulbus olfactorius

2. The tentorium (tent) of the cerebellum (tentorium cerebelli) is located horizontally in the frontal plane between the lower surface of the occipital lobes and the upper surface of the cerebellum. The posterior edge of the tent of the cerebellum is fused with the falx cerebrum, the internal eminence, the transverse groove of the occipital bone, the upper edge of the pyramid of the temporal bone and the posterior sphenoid process of the sphenoid bone. The anterior free edge limits the notch of the tent of the cerebellum, through which the legs of the brain pass into the posterior cranial fossa.

3. The sickle of the cerebellum (falx cerebelli) is located in the posterior cranial fossa vertically along the sagittal plane. It starts from the internal eminence of the occipital bone and reaches the posterior edge of the foramen magnum. It penetrates between the hemispheres of the cerebellum.

4. The diaphragm of the Turkish saddle (diaphragma sellae) limits the fossa for the pituitary gland.

5. Trigeminal cavity (cavum trigeminale) steam room, located at the top of the pyramid of the temporal bone, where the knot is placed trigeminal nerve.

The hard shell forms the venous sinuses (sinus durae matris). They are a stratified hard shell over the furrows of the bones of the skull (see Fig. 509). The elastic wall of the sinuses is formed by collagen and elastic fibers. The inner surface of the sinuses is lined with endothelium.

The venous sinuses are collectors in which venous blood is collected from the bones of the skull, the dura and pia meninges, and the brain. Inside the skull there are 12 venous sinuses (see).

Age features of the meninges. The dura mater in newborns and children has the same structure as in an adult, but in children the thickness of the dura mater and its area is less than in adults. The venous sinuses are relatively wider than in an adult. In children, features of fusion of the dura mater with the skull are noted. Up to 2 years, it is strong, especially in the area of ​​​​fontanelles and furrows, and then fusion with the bone occurs, as in an adult.

The arachnoid membrane of the brain under the age of 3 years has two sheets separated by space. Granulations of the arachnoid membranes develop only about 10 years. In children, the subarachnoid space and cisterna cerebellomedullaris are especially wide. In the soft shell after 4-5 years, pigment cells are detected.

The amount of cerebrospinal fluid also increases with age: in newborns it is 30-35 ml, at 6 years old - 60 ml, at 50 years old - 150-200 ml, at 70 years old - 120 ml.

Dura mater, dura mater, is a shiny, whitish shell of dense fibrous tissue with a large number of elastic fibers. Its outer rough surface faces the inner surface of the spinal canal and the bones of the skull; with its inner smooth shiny surface, covered with flat epithelioid cells, it is directed towards the arachnoid membrane.

Dura mater of the spinal cord

Rice. 956. Shells of the spinal cord, meninges medullae spinalis; view from above. (Transverse section through the intervertebral cartilage.)

Dura mater spinalis(Fig. 955, 956), forms a wide, cylindrical bag elongated from top to bottom. Upper bound this shell is located at the level of the large occipital foramen, along the inner surface of which, as well as lying below I cervical vertebra fuses with their periosteum. In addition, it is tightly connected to the integumentary membrane and to the posterior atlantooccipital membrane, where it is perforated by the vertebral artery. With short connective tissue strands, the shell is attached to the back longitudinal ligament spinal column. In the downward direction, the bag of the hard shell expands somewhat and, having reached the II-III lumbar vertebra, i.e., below the level of the spinal cord, it passes into the thread (hard shell) of the spinal cord, filum terminale externum, which is attached to the periosteum of the coccyx.

The hard shell extending from the spinal cord envelops the roots, nodes and nerves in the form of sheaths, expanding towards the intervertebral foramens and taking part in fixing the shell.

The dura mater of the spinal cord is innervated by branches of the meninges spinal nerves; blood supply to the branches of the vertebral arteries and the branches of the parietal arteries of the thoracic and abdominal parts of the aorta; venous blood is collected in the venous vertebral plexuses.

hard shell of the brain

Rice. 958. Nerves of the hard shell of the brain (photo. B. Perlin preparations). (Plots of totally stained dura mater.)

Dura mater encephali(Fig. 957, 958), is a strong connective tissue formation, in which the outer and inner plates are distinguished. The outer plate, lamina externa, has a rough surface, rich in blood vessels, and is adjacent directly to the bones of the skull, being their internal periosteum. Penetrating into the openings of the skull, through which the nerves exit, it covers them in the form of a vagina.

The hard shell of the brain is weakly connected with the bones of the cranial vault, with the exception of the places where the cranial sutures pass, and at the base of the skull it is firmly fused with the bones.

In children, before the fusion of the fontanelles, according to their location, the hard shell of the brain fuses tightly with the membranous skull and is closely connected with the bones of the cranial vault.

The inner lamina, lamina interna, of the dura mater is smooth, shiny and covered with endothelium.

The hard shell of the brain forms processes that are located between parts of the brain, separating them.

Along the lines of attachment of the processes of the hard shell of the brain, spaces are formed in it that have cross section prismatic or triangular shape - the sinuses of the dura mater, which are collectors through which venous blood from the veins of the brain, eyes, dura mater and cranial bones is collected in the system of internal jugular veins. These spaces - sinuses - have tightly stretched walls, do not collapse during the cut, there are no valves in them. Emissary veins open into the cavity of a number of sinuses, through which the sinuses through channels in the bones of the skull communicate with the veins of the integument of the head.

The dura mater is innervated by the meningeal branches of the trigeminal and vagus nerves, by sympathetic nerves from the periarterial plexuses (the middle meningeal artery, the vertebral artery, and the cavernous plexus), by the branches of the greater petrosal nerve and the ear node; sometimes in the thickness of some nerves there are intratrunk nerve cells. Most of the nerve branches of the meninges follow the course of the vessels of this membrane, with the exception of the cerebellum, where, unlike other parts of the dura mater of the brain, there are few vessels and where most of the nerve branches follow independently of the vessels.

The first branch of the trigeminal nerve ophthalmic nerve sends trunks to the dura mater of the anterior cranial fossa, the anterior and posterior sections of the cranial vault, as well as to the crescent of the brain, reaching the inferior sagittal sinus, and to the cerebellum tenon (branch of the tentorium). The second and third branches of the trigeminal nerve, the maxillary nerve and the mandibular nerve, send the middle branch of the meninges to the sheath of the region of the middle cranial fossa, the cerebellum and the falx cerebrum. These branches are also distributed in the walls of the nearby venous sinuses.

The vagus nerve sends a thin branch of the meninges to the dura mater of the region of the posterior cranial fossa, up to the tentorium of the cerebellum, and to the walls of the transverse and occipital sinuses. In addition, the trochlear, glossopharyngeal, accessory, and hypoglossal nerves may be involved to varying degrees in the innervation of the hard shell of the brain.

The dura mater of the brain is supplied with blood by branches coming from maxillary artery(middle meningeal artery); from the vertebral artery (branches to the meninges); from the occipital artery (meningeal branch and mastoid branch); from the ophthalmic artery (anterior ethmoidal artery - anterior meningeal artery). Venous blood is collected in the nearby sinuses of the dura mater.

Distinguish the following processes of the hard shell of the brain (see Fig. 954, 957).

1. The sickle of the cerebrum, falx cerebri, is located in the sagittal plane between both hemispheres of the cerebrum, it enters especially deeply with its anterior part. Starting in front of the cocks crest of the ethmoid bone, the crescent of the brain with its convex edge is attached to the lateral ribs of the groove of the superior sagittal sinus of the cranial vault and reaches the internal occipital protrusion, where it passes into the upper surface of the cerebellum tenon.
2. The sickle of the cerebellum, falx cerebelli, follows from the internal occipital protrusion, goes along the internal occipital crest and reaches the posterior edge of the foramen magnum, where it passes into two folds that limit the opening at the back. The crescent of the cerebellum lies between the hemispheres of the cerebellum in the region of its posterior notch.
3. The tentorium cerebellum, tentorium cerebelli, is stretched over the posterior cranial fossa, between the upper edges of the pyramids temporal bones and grooves of the transverse sinuses of the occipital bone, and separates occipital lobes cerebellum from cerebellum. It has the form of a horizontal plate, the middle part of which is drawn upwards. Its anterior free edge is concave and forms a notch of the tentorium, incisura tentorii, which limits the opening of the tentorium. This is where the brain stem runs.
4. The diaphragm of the saddle, diaphragma sellae, is stretched over the Turkish saddle, forming, as it were, its roof. Beneath it lies the pituitary gland. In the middle of the diaphragm of the saddle there is a hole through which a funnel passes, on which the pituitary gland hangs.

In the area of ​​the trigeminal depression, at the top of the pyramid of the temporal bone, the hard shell of the brain splits into two sheets. These sheets form the trigeminal cavity, cavum trigeminale, in which the trigeminal ganglion lies.

Sinuses of the dura mater of the brain

Rice. 959. Cerebral veins, vv. cerebri. (Most of the dura mater of the brain of the right hemisphere has been removed; a section of the medulla in the region of the lateral fossa of the brain has been removed; the superior sagittal and transverse sinuses, as well as the drain of the sinuses, have been opened; a part of the temporal lobe has been cut out and the veins and arteries of the insula are shown.)

There are the following sinuses of the hard shell of the brain (Fig. 959; see Fig. 957).

1. The superior sagittal sinus, sinus sagittalis superior, is located on the convex side top edge falx cerebrum. It starts from the cockscomb, goes along the midline posteriorly, gradually increasing in volume, and at the internal occipital protrusion in the region of the cruciate eminence flows into the transverse sinus.

On the sides of the superior sagittal sinus, between the sheets of the dura mater of the brain, there are numerous gaps of various sizes - lateral lacunae, lacunae laterales, into which granulations bulge.

2. The lower sagittal sinus, sinus sagittalis inferior, lies along the lower edge of the crescent of the brain and merges into the direct sinus.

3. The transverse sinus, sinus transversus, is located in the same groove of the occipital bone. It is the largest of all sinuses. Rounding the mastoid angle of the parietal bone, it continues into sigmoid sinus, sinus sigmoideus. The latter descends along the sulcus of the same name to the jugular foramen and passes into the upper bulb of the internal jugular vein.

Two emissary veins open into the sinus, which are connected with extracranial veins. One of them is in the hole mastoid process, the other - at the bottom of the condylar fossa of the occipital bone, in a non-permanent, often asymmetrical, condylar canal.

4. Direct sinus, sinus rectus, is located along the line of connection of the falx cerebrum with the cerebellum. Together with the superior sagittal sinus, they merge into the transverse sinus.

5. Cavernous sinus, sinus cavernosus, got its name due to the numerous partitions that give the sinus the appearance of a cavernous structure. The sinus is located on the sides of the Turkish saddle. On the transverse section, it looks like a triangle; three walls are distinguished in it: upper, outer and inner. top wall perforates oculomotor nerve. A little lower, in the thick outer wall sinus, the trochlear nerve and the first branch of the trigeminal nerve, the ophthalmic nerve, pass. The abducens nerve lies between the trochlear and ophthalmic nerves.

Inside the sinus passes the internal carotid artery with its sympathetic nerve plexus. The superior ophthalmic vein empties into the sinus cavity. The right and left cavernous sinuses communicate with each other in the anterior and posterior sections of the diaphragm of the saddle through the intercavernous sinuses, sinus intercavernosi. The large sinus formed in this way surrounds the pituitary gland lying in the Turkish saddle on all sides.

6. The sphenoparietal sinus, sinus sphenoparietalis, paired, follows medially along the posterior edge of the lesser wing of the sphenoid bone and flows into the cavernous sinus.

7. The superior stony sinus, sinus petrosus superior, is also a tributary of the cavernous sinus. It is located on the upper edge of the pyramid of the temporal bone and connects the cavernous sinus with the transverse sinus.

8. The lower petrosal sinus, sinus petrosus inferior, emerges from the cavernous sinus, lies between the slope of the occipital bone and the pyramid of the temporal bone in the groove of the lower petrosal sinus. It flows into the superior bulb of the internal jugular vein. The veins of the labyrinth approach it.

9. The basilar plexus, plexus basilaris, is located on the basilar part of the body of the occipital bone. It is formed by the fusion of several connecting venous branches between both inferior petrosal sinuses.

10. The occipital sinus, sinus occipitalis, lies along the internal occipital crest. It emerges from the transverse sinus, divides into two branches, which cover the lateral edges of the foramen magnum and merge into the sigmoid sinus. The occipital sinus anastomoses with the internal vertebral venous plexuses. In the place where the transverse, superior sagittal, straight and occipital sinuses are connected, a venous expansion called sinus drain, confluens sinuum. This extension corresponds to the cruciform eminence on the occipital bone.

The dura mater of the brain separates from the underlying arachnoid subdural space, spatium subdurale, which is a capillary gap in which there is a small amount of cerebrospinal fluid.

Dura mater (dura mater spinalis et encephali) (Fig. 510) lines the inner surface of the skull and spinal canal.

The hard shell consists of two layers - outer and inner. In the skull, it performs the function of the periosteum and in most of it easily exfoliates from the bones.

It is firmly attached to the bone along the edges of the openings of the base of the skull, on the crista galli, on the posterior edge of the small wings of the sphenoid bone, on the edges of the Turkish saddle, on the body of the sphenoid and occipital bones (clivus) and on the surface of the pyramids of the temporal bone. In the outer layer of the dura mater, as well as in the furrows of the bone, nerves, arteries, and two veins accompanying the arterial trunk pass.

The inner layer of the dura mater is smooth, shiny, and loosely connected to the arachnoid mater to form the subdural space.

The dura mater surrounding the spinal cord is a continuation of the dura mater of the brain. It starts from the edge of the foramen magnum and reaches the level of the III lumbar vertebra, where it ends blindly.

The hard shell of the spinal cord consists of dense outer and inner plates, consisting of collagen and elastic fibers. The outer plate makes up the periosteum and perichondrium of the spinal canal (endorachis). Between the outer and inner plates there is a layer of loose connective tissue - the epidural space (cavum epidurale), in which the venous plexuses are located.

The inner plate of the hard shell is fixed on the spinal roots in the "intervertebral foramina. In the cranial cavity, the hard shell forms crescent-shaped processes in the cracks of the brain.
1. The crescent of the brain (falx cerebri) is a very elastic plate located vertically in the sagittal plane, penetrating into the gap between the cerebral hemispheres. In front, the sickle is attached to the blind foramen of the frontal bone and the cocks crest of the ethmoid bone, with a convex edge all along it is fused with the sagittal groove of the skull and ends at the internal occipital eminence (eminentia occipitalis interna) (see Fig.

rice. 510). The inner edge of the crescent of the brain is concave and thickened, as it contains the inferior sagittal sinus and hangs over the corpus callosum. The back part of the falx of the brain is fused with a transversely located process - the cerebellum tenon.

510. Internal base of the skull with cranial nerves passing through it.
1 - n. opticus; 2-a.

Processes of the dura mater of the brain

carotis interna; 3 - n. oculomotorius; 4 - n. trochlearis; 5 - n. abducens; b - n. trigeminus; 7-n. facialis; 8-n. vestibulochlearis; 9-n. glossopharyngeus; 10-n. vagus; 11-n. hypoglossus; 12 - confluens sinuum; 13 - sinus transverse; 14 - sinus sigmoideus; 15 - sinus petrosus superior; 16 - sinus petrosus inferior; 17 - sinus intercavernousus; 18-tr. olfactorius; 19 - bulbus olfactorius

2. The tentorium (tent) of the cerebellum (tentorium cerebelli) is located horizontally in the frontal plane between the lower surface of the occipital lobes and the upper surface of the cerebellum.

The posterior edge of the tent of the cerebellum is fused with the falx cerebrum, the internal eminence, the transverse groove of the occipital bone, the upper edge of the pyramid of the temporal bone and the posterior sphenoid process of the sphenoid bone.

The anterior free edge limits the notch of the tent of the cerebellum, through which the legs of the brain pass into the posterior cranial fossa.
3. The sickle of the cerebellum (falx cerebelli) is located in the posterior cranial fossa vertically along the sagittal plane.

It starts from the internal eminence of the occipital bone and reaches the posterior edge of the foramen magnum. It penetrates between the hemispheres of the cerebellum.
4. The diaphragm of the Turkish saddle (diaphragma sellae) limits the fossa for the pituitary gland.
5. The trigeminal cavity (cavum trigeminale) is a steam room, located at the top of the pyramid of the temporal bone, where the trigeminal ganglion is placed.

The hard shell forms the venous sinuses (sinus durae matris).

They are a stratified hard shell over the furrows of the bones of the skull (see Fig. 509). The elastic wall of the sinuses is formed by collagen and elastic fibers. The inner surface of the sinuses is lined with endothelium.

The venous sinuses are collectors in which venous blood is collected from the bones of the skull, the dura and pia meninges, and the brain.

Inside the skull there are 12 venous sinuses (see).

Age features of the meninges. The dura mater in newborns and children has the same structure as in an adult, but in children the thickness of the dura mater and its area is less than in adults. The venous sinuses are relatively wider than in an adult. In children, features of fusion of the dura mater with the skull are noted. Up to 2 years, it is strong, especially in the area of ​​​​fontanelles and furrows, and then fusion with the bone occurs, as in an adult.

The arachnoid membrane of the brain under the age of 3 years has two sheets separated by space.

Granulations of the arachnoid membranes develop only about 10 years. In children, the subarachnoid space and cisterna cerebellomedullaris are especially wide.

In the soft shell after 4-5 years, pigment cells are detected.

The amount of cerebrospinal fluid also increases with age: in newborns it is 30-35 ml, at 6 years old - 60 ml, at 50 years old - 150-200 ml, at 70 years old - 120 ml.

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.

Starts ahead corpus callosum and ends at the junction big vein brain and rectum. 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. Accepts big vein brain and 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 falciform process cerebellum, connects the drain of the sinuses (confluens sinuum), runs parallel to the internal occipital crest, reaching the foramen magnum, where it connects to the sigmoid sinus, the internal jugular vein and the internal venous plexus of the spinal column.
7.

The cavernous sinus (sinus cavernosus) is paired, located on the sides of the Turkish saddle.

Calcifications of the dura mater

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.

Sinuses of the dura mater

Rice. 813. Sinuses of the dura mater, sinus durae matris; view on the right.

Important functions of the dura mater

(The right and partially left parts of the cranial vault have been removed; the right half of the brain and portions of the dura mater have been removed by sagittal incision.)

Sinuses of the dura mater, sinus durae matris (Fig.

813; see fig. 810, 815), 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 during the cut, while the walls of the sinuses are tightly stretched, formed by dense fibrous tissue. connective tissue with an admixture of elastic fibers, the lumen of the sinuses gapes when cut.

Besides, venous vessels have valves, and in the cavity of the sinuses there is a number of fibrous crossbars covered with endothelium and incomplete partitions, 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. The superior sagittal sinus, sinus sagittalis superior, has a lumen triangular shape and goes 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 arise - lateral lacunae, lacunae laterales.

2. The lower sagittal sinus, sinus sagittalis inferior, stretches along the entire lower edge of the crescent of the brain. At the lower edge of the crescent joins the direct sinus, sinus rectus.
3. The direct sinus, sinus rectus, is 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. The transverse sinus, sinus transversus, is paired, lies in the transverse groove of the bones of the skull along the posterior edge of the cerebellum.

   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. The occipital sinus, sinus occipitalis, runs in the thickness of the edge of the crescent of the 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).

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

The sphenoparietal sinus, sinus sphenoparietalis, paired, is located along the small wings of the sphenoid bone; flows into the cavernous sinus.

7. The superior petrosal sinus, sinus petrosus superior, is paired, lies in the superior petrosal groove of the temporal bone and goes from the cavernous sinus, reaching the sigmoid sinus with its posterior edge.
8. The lower petrosal sinus, sinus petrosus inferior, is paired, lies in the lower petrosal 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.

9. The 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.

In osteopathy, two opposing models of the sickle brain biomechanics exist simultaneously and equally.

The sickle of the brain, or the sickle of the great brain, also known as falx cerebri.

Osteopathy is known to be an exact science. And as in every exact science, in osteopathy, two opposite models of the sickle brain biomechanics exist simultaneously and equally. Let's try to understand both.

Sickle Mobility Model #1

This is a rather mechanistic and very logical model, and it consists in the following.

The crescent of the brain, the tent of the cerebellum and other elements of the dura mater(dura mater, pachymeninx) are a system of mutual tension membranes, or tensegrity system(tensegrity). Sometimes in early translations of foreign osteopathic texts these elements of the dura mater are called reciprocal membranes.

A little theory about tensegrity. The tensegrity mutual tension system uses a free connection of rigid elements. When exposed to such a system (in our case, it is gravity, LDM), the structure changes shape. In this case, the voltage is redistributed evenly over all elements of the system. This ensures the strength of the structure, and such a system is both adaptive and elastic.

When the position of the bones of the skull changes in the phases of flexion and extension of the craniosacral rhythm, the membranes of mutual tension take such a position that the tension is evenly redistributed throughout the entire dura system. The tension inside the membranes themselves does not change. That is, the crescent of the brain and the tent of the cerebellum work as an inextensible and elastic membrane.

The sickle brain has no proper mobility in this model. Shifting in the craniosacral rhythm, the bones of the skull set in motion the crescent of the brain and the tent of the cerebellum. The direction and form of membrane displacement are determined by the axes and vectors of craniosacral mobility of the bones to which these membranes are attached.

Shells of the brain

The brain, like the spinal cord, is surrounded by three meninges. These connective tissue sheets cover the brain, and in the region of the foramen magnum they pass into the membranes of the spinal cord. The outermost of these membranes is the dura mater of the brain. It is followed by the middle - arachnoid, and medially from it is the inner soft (vascular) membrane of the brain, adjacent to the surface of the brain.

Hard shell of the braindura mater encephali \ cra- nialis]. This shell differs from the other two in its special density, strength, and the presence in its composition of a large number of collagen and elastic fibers. Lining the inside of the cranial cavity, the dura mater is also the periosteum of the inner surface of the bones of the cerebral part of the skull. With the bones of the vault (roof) of the skull, solid

Rice. 162. Relief of the hard shell of the brain and the exit of the cranial nerves; bottom view. [ Bottom part skull (base) removed.]

1-dura mater encephali; 2 - n. opticus; 3-a. carotis interna; 4 - infundibulum; 5 - n. oculomotorius; 6n. trochlearis; 7-n. trigeminus; 8-n. abducens; 9-n. facialis et n. vestibulocochlearis; 10-nn. glossopharyn-geus, vagus et accessorius; 11-n. hypoglossus; 12-a. vertebralis; 13 - n. spinalis.

the membrane of the brain is not firmly connected and is easily separated from them. In the region of the base of the skull, the shell is firmly fused with the bones, especially at the junctions of the bones with each other and at the points of exit from the cranial cavity of the cranial nerves (Fig. 162). The hard sheath surrounds the nerves for some distance, forming their sheaths, and fuses with the edges of the holes through which these nerves leave the cranial cavity.

On the inner base of the skull (in the region of the medulla oblongata), the dura mater fuses with the edges of the foramen magnum and continues into the dura mater of the spinal cord. The inner surface of the hard shell, facing the brain (to the arachnoid), is smooth. In some places, the dura mater of the brain

Rice. 163. Hard shell of the brain, dura mater encephali [ cranialisj.

1 - falx cerebri; 2 - sinus rectus; 3 - tentorium cerebelli; 4 - diaphragma sellae; 5 - n. opticus et a. carotis interna.

it splits and its inner leaflet (duplicature) deeply bulges in the form of processes into the cracks separating parts of the brain from each other (Fig. 163). In the places where the processes originate (at their base), as well as in areas where the hard shell is attached to the bones of the inner base of the skull, in the splits of the hard shell of the brain, triangular-shaped channels lined with endothelium are formed - sinuses of the dura matershells,sinus Durae tnatris.

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 crescent cerebrum (large falciform process), falx cerebri. This is a thin sickle-shaped plate of the hard shell, which in the form of two sheets penetrates into the longitudinal fissure of the cerebrum. Not reaching the corpus callosum, this plate separates the right and left hemisphere big brain. In the split base of the falx cerebrum, 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 large sickle

the brain also between its two leaves is the lower sagittal sinus. In front, the crescent of the brain is fused with the cockscomb of the ethmoid bone. The posterior part of the sickle at the level of the internal occipital protrusion fuses with the tentorium of the cerebellum. Along the line of fusion of the posterior lower edge of the falx cerebrum and the cerebellum in the cleavage of the dura mater, there is a straight sinus connecting the inferior sagittal sinus with the superior sagittal, transverse, and occipital sinuses.

Namet(tent) 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 of the cerebellum, the cerebellar mantle separates the occipital lobes from the cerebellar hemispheres. The anterior margin of the cerebellum is uneven. It forms a notch, Incisura tentorii, to which the brain stem is attached in front.

The lateral edges of the cerebellum tenon are fused with the upper edge of the pyramids of the temporal bones. Behind the cerebellum, the cerebellum passes into the hard shell of the brain, lining the occipital bone from the inside. At the site of this transition, the dura mater of the brain forms a transverse sinus adjacent to the occipital sulcus of the same name.

Falx cerebellum(small falciform process), fdlx cerebelli, like a sickle of the brain, located in the sagittal plane. Its anterior margin is free and penetrates between the hemispheres of the cerebellum. The posterior edge of the falx cerebellum continues to the right and left into the inner sheet of the dura mater of the brain, extending from the inner occipital protrusion at the top to the posterior edge of the foramen magnum below. The occipital sinus forms at the base of the falx cerebellum.

Diaphragm(turkish) saddles,diaphragma sellae, is a horizontal plate with a hole in the center, stretched over the pituitary fossa and forming its roof. Under the diaphragm of the saddle in the fossa is the pituitary gland. Through a hole in the diaphragm, the pituitary gland is connected to the hypothalamus with the help of a funnel.

Sinuses of the dura mater of the brain. The sinuses (sinuses) of the hard shell 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 (Fig. 164).

The sheets of the hard shell that form the sinus are tightly stretched and do not fall off. Therefore, on the cut, the sinuses gape; 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 bones of the skull, at the locations of the sinuses of the hard shell,

Rice. 164. The relationship of the membranes of the brain and the superior sagittal sinus with the vault of the skull and the surface of the brain; incision in the frontal plane (scheme).

1 - dura mater; 2-calvaria; 3 - granulationes arachnoidales; 4 - sinus sagittalis superior; 5 - cutis; 6-v. emissaria; 7 - arachnoidea; 8 - cavum subarachnoidale; 9 - pia mater; 10 - encephalon; 11 - falx cerebri.

there are corresponding grooves. There are the following sinuses of the hard shell of the brain (Fig. 165).

1. superior sagittal sinus,sinus sagittalis superior, located along the entire outer (upper) edge of the crescent of the brain, from the cockscomb of the ethmoid bone to the internal occipital protrusion. 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 are lateral lacunae communicating with it, lacunae laterdles. These are small cavities between the outer and inner layers(leaves) of the hard shell 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 veins of the brain, and the diploic veins flow into them.

Rice. 165. Sinuses of the hard shell of the brain; side view.

1 - sinus cavernosus; 2 - sinus petrosus inferior; 3 - sinus petrosus superior; 4 - sinus sigmoideus; 5 - sinus transverse; 6 - sinus occipitalis; 7 - sinus sa-gittalis superior; 8 - sinus rectus; 9 - sinus sagittalis inferior.

inferior sagittal sinus,sinus sagittalis inferior, located in the thickness of the lower free edge of the falx cerebrum; it is much smaller than the top. 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 cerebrum fuses with the anterior edge of the cerebellum tenon.

straight sinus,sinus rectus, located sagittally in the splitting of the cerebellar tentorium along the line of attachment of the falx cerebrum to it. The straight sinus connects the posterior ends of the superior and inferior sagittal sinuses. In addition to the inferior sagittal sinus, a large cerebral vein flows into the anterior end of the direct sinus. Behind the straight sinus flows into the transverse sinus, into its middle part, called the sinus drain. The posterior part of the superior sagittal sinus and the occipital sinus also flow into this.

transverse sinus,sinus transverse, lies at the place where the cerebellum is separated from the dura mater of the brain. On the inner surface of the scales of the occipital bone, this is

This sinus corresponds to a wide groove of the transverse sinus. The place where the superior sagittal, occipital and direct sinuses flow into it is called the sinus drain (sinus fusion), confluens sinuum. On the right and left, the transverse sinus continues into the sigmoid sinus of the corresponding side.

occipital sinus,sinus occipitalis, lies at the base of the falx cerebellum. Descending along the internal occipital crest, it reaches the posterior edge of the large occipital foramen, where it divides into two branches, covering this foramen from behind and from the sides. Each of the branches of the occipital sinus flows into the sigmoid sinus of its side, and the upper end into the transverse sinus.

sigmoid sinus,sinus sigmoideus (paired), located in the sulcus of the same name on the inner surface of the skull, has an S-shape. In the region of the jugular foramen, the sigmoid sinus passes into the internal jugular vein.

cavernous sinus,sinus cavernosus, paired, located on the base of the skull on the side of the Turkish saddle. The internal carotid artery and some cranial nerves pass through this sinus. This sinus has a very complex structure 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 Turkish saddle, in front of and behind the funnel of the pituitary gland. The sphenoid-parietal sinus and the superior ophthalmic vein flow into the anterior sections of the cavernous sinus.

sphenoparietal sinus,sinus sphenoparietalis, paired, adjacent to the free posterior edge of the small wing of the sphenoid bone, in the splitting of the hard shell of the brain attached here.

superior and inferior petrosal sinuses,sinus petrosus su­ perior et sinus petrosus inferior, paired, lie along the upper and lower edges of the pyramid of the temporal bone. Both sinuses take part in the formation of outflow tracts of venous blood from the cavernous sinus to the sigmoid. The right and left lower stony sinuses are connected by several veins lying in the splitting of the hard shell in the region of the body of the occipital bone, which are called the basilar plexus. This plexus connects through the foramen magnum with the internal vertebral venous plexus.

In some places, the sinuses of the hard shell of the brain form anastomoses with the external veins of the head with the help of emissary veins - graduates, vv. emissariae. In addition, the sinuses of the dura have communications with the diploic veins, vv. dipioicae located in the spongy substance of the bones of the cranial vault and flowing into the superficial

head veins. Thus, venous blood from the brain flows through the systems of its superficial and deep veins into the sinuses of the hard shell of the brain and further into the right and left internal jugular veins.

In addition, due to sinus anastomoses 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 hard shell of the brain. TO The middle meningeal artery (a branch of the maxillary artery), which branches in the temporo-parietal section of the membrane, approaches the hard shell of the brain through the right and left spinous foramina. The dura mater of the brain lining the anterior cranial fossa is supplied with blood by the branches of the anterior meningeal artery (a branch of the anterior ethmoidal artery from the ophthalmic artery)". the jugular foramen, as well as the meningeal branches from the vertebral artery and the mastoid branch from the occipital artery, which enters the cranial cavity through the mastoid foramen.

The veins of the soft shell of the brain flow into the nearest sinuses of the hard shell, as well as into the pterygoid venous plexus (Fig. 166).

The dura mater of the brain is innervated by the branches of the trigeminal and vagus nerves, as well as by sympathetic fibers entering the shell in the thickness of the adventitia of the blood vessels. The dura mater in the region of the anterior cranial fossa receives branches from the optic nerve (the first branch of the trigeminal nerve). The branch of this nerve, the tentorial (shell) branch, supplies the cerebellum and the crescent of the brain. The middle meningeal branch from the maxillary nerve, as well as the branch from the mandibular nerve, approach the membrane in the middle cerebral fossa. In the sheath lining the posterior cranial fossa, the meningeal branch of the vagus nerve branches.

arachnoid membrane of the brain,arachnoidea mater (encephali) [ cranialis]. This shell is located medially from the hard shell of the brain. The thin, transparent arachnoid, unlike the soft membrane (vascular), does not penetrate into the gaps between the individual parts of the brain and into the furrows of the hemispheres. It covers the brain, passing from one part of the brain to another, and lies above the furrows. The arachnoid is separated from the pia mater of the brain subarachnoid(subarachnoid) space,cavitas [ spdtium] sub- arachnoidalis [ subarachnoideum], which contains cerebrospinal fluid liquor cerebrospindlis. In places,

Rice. 166. Veins of the pia mater of the brain.

1 confluence of veins in the superior sagittal sinus; 2 - superficial cerebral veins; 3 - sigmoid sinus.

where the arachnoid membrane is located above the wide and deep furrows, the subarachnoid space is expanded and forms a larger or smaller size subarachnoid cisterns,cister- paesubarachnoideae.

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

The largest subarachnoid cisterns are as follows.

cerebellar cistern,clsterna cerebellomedulla- ris, located between medulla oblongata ventrally and cerebellum dorsally. Behind, it is limited by the arachnoid membrane. This is the largest of all tanks.

Cistern of the lateral fossa of the brain,cisterna fos­ sae laterdlls cerebri, is located on the lower lateral 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.

cross tank,cisterna chiasmatis [ chiasmatica], located at the base of the brain, anterior to the optic chiasm.

interpeduncular cistern,cisterna interpeduncularis, is determined in the interpeduncular fossa between the legs of the brain, downwards (anteriorly) 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.

The cerebrospinal fluid that fills the subarachnoid space is produced by the choroid plexuses of the ventricles of the brain. From the lateral ventricles through the right and left interventricular foramen cerebrospinal fluid goes to III ventricle, where there is also a choroid plexus. From III ventricle through the cerebral aqueduct, cerebrospinal fluid enters the fourth ventricle, and from it through an unpaired opening into back wall and a paired lateral aperture into the cerebellar-cerebral cistern of the subarachnoid space.

The arachnoid membrane is connected to the pia mater lying on the surface of the brain by numerous thin bundles of collagen and elastic fibers. Near the sinuses of the hard shell of the brain, the arachnoid membrane forms a kind of protrusion - arachnoid granulation,gra- nulationes arachnoideae (pachion granulations). These protrusions protrude into the venous sinuses and lateral lacunae of the hard shell. On the inner surface of the bones of the skull, at the location of the granulations of the arachnoid membrane, there are impressions - dimples of granulations. Granulations of the arachnoid membrane are organs where the outflow of cerebrospinal fluid into the venous bed is carried out.

Soft(vascular) shell of the brainRia mater encephali [ cranialis]. It is the innermost layer of the brain. She is close to outer surface brain and goes into all the cracks and furrows. soft shell It consists of loose connective tissue, in the thickness of which there are blood vessels that go to the brain and feed it. In certain places, the soft shell penetrates into the cavities of the ventricles of the brain and forms vascular plexus,plexus choroidus, producing cerebrospinal fluid.

Review questions

Name the processes of the hard shell of the brain. Where is each process located in relation to the parts of the brain?

List the sinuses of the dura mater of the brain. Where does each sinus fall into (open)?

Name the cisterns of the subarachnoid space. Where is each tank located?

Where does the cerebrospinal fluid drain from the subarachnoid space? Where does this fluid enter the subarachnoid space?

Age features of the membranes of the brainand spinal cord

The dura mater of the brain in a newborn is thin, tightly fused with the bones of the skull. The shell processes are poorly developed. The sinuses of the dura mater of the brain and spinal cord 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 15 mm posterior to the tympanic ring of the external auditory canal. There is a greater than in an adult, asymmetry in the size of the sinuses. 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, delicate. The subarachnoid space is relatively large. Its capacity is about 20 cm 3, it increases rather 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 of 8 years old, the volume of the subarachnoid space reaches 100-140 cm 3, in an adult it is 100-200 cm 3. The cerebellar, interpeduncular, and other cisterns at the base of the brain in a newborn are quite large. So, the height of the cerebellar-cerebral cistern is about 2 cm, and its width (at the upper border) varies from 0.8 to 1.8 cm.