Structure of the skull: sections. Great Medical Encyclopedia Clive of the occipital bone

Occipital bone , os occipitale, unpaired, forms the posteroinferior part of the skull. Its outer surface is convex, and its inner, cerebral, concave surface. In its antero-inferior section there is a large (occipital) foramen, foramen magnum, connecting the cranial cavity with the spinal canal. This opening is surrounded by a shallow groove of the occipital sinus, sulcus sinus occipitalis. Based on data on the process of development of the occipital bone, four parts are distinguished in it surrounding the large (occipital) foramen: the basilar part - in front of the large (occipital) foramen, paired lateral parts - on the sides of it, and the occipital scales, located behind.

Basilar part, pars basilaris. short, thick, quadrangular; its posterior edge is free, smooth and slightly pointed, limiting the foramen magnum (occipital) in front; the anterior edge is thickened and rough, connected to the body through cartilage, forming the sphenooccipital synchondrosis, synchondrosis sphenooccipitalis.

IN teenage years cartilage is replaced bone tissue and both bones merge into one. The upper surface of the basilar part, facing, is smooth and slightly concave. It forms a slope, clivus, with the part of the body of the sphenoid bone located in front of it, directed towards the large (occipital) foramen (the medulla oblongata, the bridge and the basilar artery of the brain with branches lie on it). In the middle of the lower, outer, slightly convex surface of the basilar part there is a small pharyngeal tubercle, tuberculum pharyngeum (the place of attachment of the anterior longitudinal ligament and the fibrous membrane of the pharynx), and rough lines (traces of the attachment of the longus capitis muscles).

The outer, slightly irregular edge of the basilar and lateral parts of the occipital bone is adjacent to the posterior edge of the petrosal. Between them a stony-occipital fissure, fissura petrooccipitalis, is formed; on a non-macerated skull it is made of cartilage, forming the petrooccipital synchondrosis, synchondrosis petrooccipitalis, which, as a remnant of the cartilaginous skull, ossifies with age.

The lateral parts, paries laterales, are somewhat elongated, thickened in the posterior sections, and somewhat narrowed in the anterior ones; they form the lateral sides of the large (occipital) foramen, fused in front with the basilar part, and behind with the occipital scales.


On the brain surface of the lateral part, at its outer edge, there is a narrow groove of the inferior petrosal sinus, sulcus sinus petrosi inferioris, which is adjacent to the posterior edge of the petrosal part, forming with the groove of the same name in the temporal bone a canal where the venous inferior petrosal sinus, sinus petrosus inferior, lies.

On the lower, outer surface of each lateral part there is an oblong-oval convex articular process - the occipital condyle, condylus occipitalis. Their articular surfaces come closer in front and diverge behind; they articulate with the superior articular fossa of the atlas. Behind the occipital condyle there is a condylar fossa, fossa condylaris, and at its bottom there is a hole leading into the unstable condylar canal, canalis condylaris, which is the location of the condylar emissary vein, v. emissaria condylaris.

On the outer edge of the lateral part there is a large, smooth-edged jugular notch, incisura jugularis, on which a small intrajugular process, processus intrajugularis, protrudes. The jugular notch with the same fossa of the petrous part of the temporal bone forms the jugular foramen, foramen jugulare.

The intrajugular processes of both bones divide this opening into two parts: the large posterior one, in which lies the superior bulb of the internal jugular vein, bulbus v. jugularis superior, and the smaller anterior one, through which the cranial nerves pass: glossopharyngeal, n. glossopharyngeus, wandering, n. vagus, and accessory, n. accessorius.

The jugular notch is limited posteriorly and externally by the jugular process, processus jugularis. On the outer surface of its base there is a small paramastoid process, processus paramastoideus (place of attachment of the straight lateral, m. rectus capitis lateralis).

Behind the jugular process, on the side of the inner surface of the skull, there runs a wide groove of the sigmoid sinus, sulcus sinus sigmoidei, which is a continuation of the groove of the same name in the temporal bone. Anterior and medial lies the smooth jugular tubercle, tuberculum jugulare. Posteriorly and downward from the jugular tubercle, between the jugular process and the occipital condyle, the hypoglossal canal, canalis hypoglossalis, passes through the bone (it contains the hypoglossal nerve, n. hypoglossus).

The occipital scales, squama occipitalis, limit the large (occipital) foramen at the back and make up most of the occipital bone. This is a wide curved plate triangular shape with a concave inner (brain) surface and a convex outer surface.

The lateral edge of the scales is divided into two sections: a larger upper, strongly jagged lambdoid edge, margo lambdoideus, which, joining the occipital edge of the parietal bones, forms a lambdoid suture, sutura lambdoidea, and a smaller lower, weakly jagged mastoid edge, margo mastoideus, which , adjacent to the edge of the mastoid process of the temporal bone, forms the occipitomastoid suture, sutura occipitomastoidea.

In the middle of the outer surface of the scales, in the area of ​​its greatest convexity, there is an external occipital protrusion, protuberantia occipitalis externa, easily palpable through the skin. From it, paired convex upper nuchal lines, lineae nuchae superiores, diverge to the sides, above which and parallel to them there are additional highest nuchal lines, lineae nuchae supremae.

From the external occipital protuberance, the external occipital crest, crista occipitalis externa, descends to the foramen magnum. In the middle of the distance between the large (occipital) foramen and the external occipital protrusion, the lower nuchal lines, lineae nuchae inferiores, running parallel to the upper ones, diverge from the middle of this crest to the edges of the occipital scales. All these lines are places of muscle attachment. On the surface of the occipital scales below the upper nuchal lines, muscles ending on the occipital bone are attached.

On the brain surface, facies cerebralis, of the occipital scales there is a cruciform eminence, eminentia cruciformis, in the middle of which rises the internal occipital protuberance, protuberantia occipitalis interna. On the outer surface of the scales it corresponds to the external occipital protrusion.

The groove of the transverse sinus, sulcus sinus transversi, extends from the cruciform eminence in both directions, upward - the groove of the superior sagittal sinus, sulcus sinus sagittalis superioris, downwards - the internal occipital crest, crista occipitalis interna, going to the posterior semicircle of the large (occipital) foramen. The dura mater with the venous sinuses located in it is attached to the edges of the grooves and to the internal occipital crest; in the region of the cruciate eminence there is a confluence of these sinuses.

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The skull consists of several unpaired bones connected to each other and bears very important functions, namely, protection of the brain and sensory organs. In addition, the initial sections of the digestive and respiratory organs, as well as a number of muscles, are attached to it.

Differentiate between the cerebral skull and the facial skull. The occipital flat bone belongs to the medulla; its structure will be described below.

General information

The occipital bone is odd, located in the back of the skull, composed of 4 elements encircling the large foramen of the anterioinferior section outer surface.
What is the normal anatomy of the occipital bone.

Basilar - the main part lying to the anterior side of the external opening. In a child, the basilar part and the sphenoid bone are connected by cartilage, resulting in the formation of occipital-sphenoid synchondrosis. In boys and girls, after reaching adulthood, the bones grow together as the cartilage is replaced by bone tissue.

Superficial basilar part with inside, directed towards the cranial cavity, is smooth and slightly concave. The brain stem is partially located on it. In the area where the outer edge is located, there is a groove for the petrous inferior sinus, which is adjacent to the back of the petrous part of the temple. The outer surface, located below, is convex and rough. In the middle is the pharyngeal tubercle.

Side part

The lateral or lateral part is paired, the shape is elongated. On the surface below and outside there are articular ellipsoidal processes called occipital condyles. Any condyle has an articular surface that articulates it with the first cervical vertebra. On the posterior side there is a condylar fossa, into which lies the unstable condylar canal.

The condyle at its base is pierced by the hypoglossal canal. It should be noted that the hypoglossal canal passes through the bone. The lateral edge has a jugular notch, which unites with the notch of the temporal bone, which is also called, resulting in the jugular foramen. Passes through it jugular vein, as well as nerves: vagus, accessory and glossopharyngeal.

Rear end

Anatomy of the occipital bone

The most massive part of the occipital bone is the occipital squama, located behind the large foramen magnum and participating in the formation of the cranial vault and base. The occipital scale is a covering bone. In the central part from the outside, the scales have an external occipital protrusion. It can be easily felt through the skin.

The external nuchal crest runs from the external protrusion towards the foramen magnum. The upper paired nuchal lines branch off to both sides of the outer ridge. They are a trace of muscle attachment. They are located at the level of the outer ridge, and the lower ones in the middle of the outer ridge.

Sphenoid bone. It is unpaired, located in the central part of the base of the skull. The sphenoid bone has a complex shape, it contains a body, small and large wings, as well as pterygoid processes.

The mastoid process is a raised area of ​​the skull located behind the ear. Air cells are located here auditory tube, which connect to the middle ear. The mastoid margin, located on the occipital bone, is the edge of the occipital scales that connects to the temple bone. The occipital-mastoid suture is a mastoid edge connected to the surface of the temple bone, which has a posterior location.

Lateral masses

They are laterally limited by the large foramen magnum. On the outer surface there are condyles that serve as connectors of the articular surfaces of the atlas. What about lateral masses?

Firstly, these are the jugular processes, which limit the jugular foramen on the sides. The jugular process is located in the same place as the posterior edge of the jugular notch. The sigmoid sinus runs along the back of the skull. It has the shape of an arc and is a continuation of the groove with the same name, but in the temporal bone. The area covering the hypoglossal canal has a flat, smooth jugular tubercle.

It is also the hypoglossal canal (hypoglossal nerve canal), located lateral and anterior to the major foramen. Behind the condyle is the condylar canal, which contains the emissary vein.

Occipital bone injuries

The occipital bone, like the entire skull, is susceptible to injury, which can have fatal consequences, since it is in this part of the skull that protects the visual center. Therefore, serious damage can lead to partial or complete loss of vision.

Types of injuries to the occipital bone:

  1. Depressed fracture of the occipital bone: occurs when the skull, namely the occipital bone, is impacted by a small blunt object. In this case, as a rule, the brain suffers.
  2. Splintered damage: a violation of integrity, which is characterized by the appearance of fragments of different sizes. As a result, the bone loses its function and the structure of the brain is damaged.
  3. A linear fracture is a violation of the anatomical integrity of a bone, in which fractures of other bones, bruises and concussions are often observed. On x-ray, a linear fracture looks like a thin strip that divides the skull, namely the occipital flat bone.

A linear fracture is characterized by the fact that the displacement of the bones relative to each other is no more than a centimeter. Such a fracture of the occipital bone may go unnoticed and not manifest itself in any way. Such an injury is especially dangerous in a child, and children are often at risk of getting it due to carelessness during games. If your child experiences nausea and headache, you need to urgently consult a doctor.

If the skull has sustained an injury that involves the greater occipital canal, cranial nerves will be damaged. IN in this case The clinical picture will show bulbar symptoms, in which the functions of the cardiovascular and respiratory system. The consequences can be the most terrible: disruption of some brain functions, osteoma of the occipital bone, death.

Traumatic brain injuries of the occipital region

There are three main forms of damage:

  • concussion;
  • brain contusion;
  • compression of the brain.

The most common sign of a concussion is fainting, lasting from 30 seconds to half an hour. In addition, the victim experiences vomiting, nausea, headaches, and dizziness. There is a possibility of short-term memory loss, irritability to light and noise.

Minor bruise occipital bone is accompanied by a short-term loss of consciousness

If the occipital bone is damaged and a concussion occurs along with it, a whole set of symptoms will appear, which may also be present with a concussion. A slight bruise is accompanied by a short-term loss of consciousness lasting from several minutes to several hours. Often there is a short-term speech disorder, paralysis of the facial muscles. If the victim received a moderate injury, his pupils may react poorly to light, and nystagmus appears - involuntary vibrations of the eyes. If a severe injury occurs, the patient may fall into a coma lasting up to several days.

A severe bruise can cause compression of the brain. As a rule, this occurs due to the development of an intracranial hematoma, but often the cause is cerebral edema, bone fragments, or all these reasons in combination. Compression of the brain usually requires immediate surgical intervention.

Possible complications

The most terrible result for a person who has received an injury is unilateral visuospatial agnosia, which doctors call the disorder various types perception. That is, the victim is not able to see and perceive the space located on the left.

The consequences of injuries can be as follows:

  • traumatic asthenia (decreased performance, lack of composure, increased excitability, poor sleep);
  • migraines, dizziness, sensitivity to weather changes;
  • poor memory;
  • unstable behavior;
  • depression;
  • hallucinations and other consequences associated with mental disorders.

Sometimes victims feel that the injuries they received do not pose any danger and are minor. However, if the skull is injured, then this is a serious reason to consult a doctor. A negligent attitude towards one's health can cause extreme unpleasant consequences, which in the future can interfere with normal life.

The occipital bone of the skull, a photo of which is presented in the article, is unpaired. It is located in the lower back. This element forms part of the arch and participates in the formation of the base. You can often hear the question from schoolchildren: “Is the occipital bone of the skull flat or tubular?” In general, all solid elements of the head have the same structure. The occipital bone, like the others, is flat. It includes several elements. Let's take a closer look at them.

Occipital bone of the skull: anatomy

This element is connected to the temporal and parietal ones through sutures. The occipital bone of the human skull includes 4 parts. It is of cartilaginous and membranous origin. The occipital bone of the animal's skull includes:

  1. Scales.
  2. Two articular condyles.
  3. Body.
  4. Two jugular processes.

Between these parts there is a large hole. Through it there is communication between the brain cavity and the spinal canal. The occipital bone of the human skull articulates with the sphenoid element and the 1st cervical vertebra. It includes:

  1. Scales.
  2. Condyles (lateral masses).
  3. Body (basilar part).

There is also a large hole between them. It connects the cranial cavity with the spinal canal.

Scales

It is a spherical plate. Its outer surface is convex, and its inner surface is concave. When considering the structure of the occipital bone of the skull, one should study the structure of the plate. On its outer surface there are:

  1. Projection (inion). It is presented in the form of an elevation in the center of the scales. When palpated, it can be felt quite well.
  2. Occipital platform. It is represented by a section of scales above the protrusion.
  3. Nuchal highest line. It starts from upper limit inion.
  4. Nuchal upper line. It runs at the level of the protrusion between the lower and highest edges.
  5. Bottom line. It passes between the upper edge and the occipital foramen.

Inner surface

It contains:

  1. Cross-shaped elevation. It is located at the intersection of the internal ridge and grooves of the transverse and superior sagittal sinuses.
  2. Inner ledge. It is located at the junction of the venous sinuses.
  3. Inner ridge.
  4. Grooves: one sagittal and two transverse sinuses.
  5. Opistion. This is an identification point. It corresponds to the center of the posterior edge of the occipital foramen.
  6. Bazion. This is a conditional stitch that corresponds to the center of the anterior edge of the occipital foramen.

The inner surface of the scales has a relief, which is determined by the shape of the brain and the membranes adjacent to it.

Lateral masses

They contain:

  1. Jugular processes. They limit the hole of the same name on the sides. These elements correspond to the transverse vertebral processes.
  2. Sublingual canal. It is located lateral and anterior to the foramen magnum. It contains the XII nerve.
  3. Condylar canal located behind the condyle. It contains an emissary vein.
  4. Jugular tubercle. It is located above the channel

Body

It represents the very front part. The body is sloping at the top and front. It distinguishes:

  1. Bottom surface. It has a pharyngeal tubercle, the site of attachment of the pharyngeal suture.
  2. Two outer lines (edges). They are connected to the pyramids of the temporal element.
  3. Slope (upper surface). It is directed into the cranial cavity.

In the lateral part the groove of the petrosal inferior sinus is distinguished.

Articulations

The occipital bone of the skull is connected to the elements of the vault and base. It acts as a link between the head and the spine. As mentioned above, in the part of the head under consideration, the sphenoid element and the occipital bone of the skull are connected. Type of articulation - synchondrosis. The connection is made using the front surface of the body. It articulates with the occipital by a suture. At the junction there is a conditional point. It is called "lambda". In some cases, the interparietal bone is found here. It is formed from the upper part of the scales and is separated from it using a transverse seam. The occipital bone of the skull articulates with the temporal element by sutures:

  1. Petro-jugular. The jugular process articulates with the notch of the same name in the temporal bone.
  2. Petro-basilar. The lateral part of the base is connected to the pyramid of the temporal element.
  3. Occipitomastoid. The mastoid part articulates with the posteroinferior plane of the temporal element.

With the atlas, the lower convex surface of the condyles connects with the concave parts of the 1st vertebra of the neck. Here a joint of the diarthrosis type is formed. It contains a capsule, synovium, and cartilage.

Ligaments

They are presented in the form of membranes:

  1. Front. It is located between the base of the bone and the arch of the atlas.
  2. Rear. This ligament is stretched between the back parts of the first vertebra of the neck and the foramen magnum. It is included in the composition of the corresponding surface of the spinal canal.
  3. Lateral. This membrane connects the jugular process to the transverse vertebral process.
  4. Pokrovnoy. It is a continuation of the longitudinal posterior membrane towards the front of the large hole. This ligament passes into the periosteum of the elements

In addition, there are:

  1. Pterygoid ligaments. They go to the lateral parts of the foramen magnum.
  2. Tooth ligament. It runs from the process of the 2nd cervical vertebra to the anterior border of the foramen magnum.
  3. Superficial aponeurosis. It is attached along the nuchal superior line.
  4. Deep aponeurosis. It is attached to the base of the occipital bone.

Muscles

They are attached to:

On the bottom line are recorded:

  1. Rectus capitis posterior minor muscle. It is attached to the spinous process of the 1st vertebra of the neck.
  2. The back is a big straight line. They are attached to the 2nd vertebra of the neck.
  3. Oblique superior muscle heads. It is attached to the transverse process of the 2nd cervical vertebra.

and nerves

The tentorium of the cerebellum is attached to the edges of the transverse sulcus. The falx of the brain is fixed by its back. It is attached to the edges of the groove on the superior sagittal sinus. The cerebellar falx is fixed on the occipital internal crest. Pairs of nerves pass through the jugular foramen:

  1. Glossopharyngeal (IX).
  2. Wandering (X).
  3. Additional (XI). Its spinal roots pass through the foramen magnum.

At the level of the condyles, the XII pair of nerves passes through the hypoglossal canal.

Injuries

The structure of the occipital bone of the skull is such that it is highly susceptible mechanical damage. Moreover, they can be accompanied by serious, in some cases, fatal consequences. This is due to the fact that the occipital bone of the skull protects optic nerve. And its damage can lead to complete or partial loss of the ability to see.

Types of injuries

The following damages exist:

  1. Depressed fracture of the occipital bone of the skull. It appears from mechanical impact with a blunt object. In such situations, the brain usually bears most of the load.
  2. Splinter damage. It represents a violation of the integrity of the element, accompanied by the formation of fragments of various sizes. This can cause damage to the brain structure.
  3. Linear fracture of the occipital bone of the skull. It also represents a violation of the integrity of the element. In this case, the damage is often accompanied by fractures of other bones, concussion and brain contusion. Such an injury x-ray looks like a thin strip. It divides the skull, namely its occipital bone.

The last damage is different in that the displacement of the elements relative to each other is no more than a centimeter. This fracture may go unnoticed and not manifest itself in any way. This injury occurs especially often in children during active play. If your child experiences headaches and nausea after a fall, you should consult a doctor.

A special case

The skull may suffer damage involving the foramen magnum. In this case, the brain nerves will also be injured. The clinical picture is characterized by bulbar symptoms. It is accompanied by disorders of the respiratory and cardiovascular systems. The consequences of such an injury are quite serious. This can be a violation of certain brain functions, osteoma of the occipital bone, and even death.

TBI

There are three main types of brain damage:

  1. Shake.
  2. Squeezing.
  3. Injury.

The most common signs of a concussion include fainting lasting 30 seconds or more. up to half an hour. In addition, a person experiences nausea, vomiting, dizziness, and headaches. Short-term memory loss and irritability to noise and light are possible. With simultaneous damage to the occipital bone and concussion, a complex of symptoms is observed. A slight bruise is manifested by loss of consciousness. It can be short-lived (a few minutes) or last several hours. Paralysis and speech impairment are often observed. With a moderate injury, there is a poor reaction of the pupils to light, and nystagmus occurs - involuntary twitching of the eyes. If the damage is severe, the victim may fall into a coma for several days. In this case, compression of the brain may also occur. This occurs due to the development of a hematoma. However, in some cases, compression can cause swelling or bone fragments. This condition usually requires emergency surgery.

Consequences

Injuries to the occipital bone can cause unilateral visuospatial agnosia. Doctors call this condition a disorder different types perception. The victim, in particular, cannot see or understand the space to his left. In some cases, people believe that what they received does not pose a danger to them. However, for any damage, regardless of severity, you must go to the hospital. A condition that does not show any symptoms in the early stages can cause serious consequences.

The occipital bone, os occipitalae, unpaired, forms the posterior part of the base and roof of the skull. There are four parts in it: the main part, pars basilaris, two lateral parts, partes laterales, and the scales, squama. In a child, these parts are separate bones connected by cartilage. In the 3rd to 6th year of life, the cartilage ossifies and they grow together into one bone. All these parts, joining together, limit a large hole, foramen magnum. In this case, the scales lie behind this hole, the main part is in front, and the side ones are on the sides. The scales are mainly involved in the formation of the posterior part of the roof of the skull, and the main and lateral parts are the base of the skull.
The main part of the occipital bone is wedge-shaped, the base of which faces forward toward the sphenoid bone, and the apex faces posteriorly, delimiting the large foramen in front. In the main part, five surfaces are distinguished, of which the upper and lower are connected at the back at the anterior edge of the occipital foramen. The anterior surface is connected by the sphenoid bone until the age of 18–20 with the help of cartilage, which subsequently ossifies. The upper surface, the slope, clivus, is concave in the form of a groove, which is located in the sagittal direction. The medulla oblongata, pons, vessels and nerves are adjacent to the clivus. In the middle of the lower surface there is a pharyngeal tubercle, tuberculum pharyngeum, to which the initial part of the pharynx is attached. On each side of the pharyngeal tubercle, two transverse ridges extend from each side, of which m. is attached to the anterior one. longus capitis, and to the rear - m. rectus capitis anterior. The lateral rough surfaces of the main part are connected through cartilage to rocky part temporal bone. On their upper surface, near the lateral edge, there is a small groove of the inferior petrosal sinus, sulcus sinus petrosi inferioris. It is in contact with a similar groove in the petrous part of the temporal bone and serves as the place to which the inferior petrosal venous sinus of the dura mater is adjacent.
The lateral part is located on both sides of the occipital foramen and connects the main part with the scales. Its medial edge faces the foramen magnum, the lateral edge faces the temporal bone. The lateral margin bears the jugular notch, incisura jugularis, which, with the corresponding notch of the temporal bone, limits the jugular foramen. The intrajugular process, processus intrajugularis, located along the edge of the notch of the occipital bone, divides the foramen into anterior and posterior. The internal jugular vein passes in the anterior one, and the IX, X, IX pairs pass in the posterior cranial nerves. The posterior part of the jugular notch is limited by the base of the jugular process, processus jugularis, which faces the cranial cavity. Posterior and inside of the jugular process, on the inner surface of the lateral part there is a deep groove of the transverse sinus, sulcus sinus transverse. In the anterior section of the lateral part, on the border with the main part, there is a jugular tubercle, tuberculum jugulare, and on the lower surface there is an occipital condyle, condylus occipitalis, with which the skull articulates with the first cervical vertebra. The condyles, according to the shape of the upper articular surface of the atlas, form oblong ridges with convex oval articular surfaces. Behind each condyle there is a condylar fossa, fossa condylaris, at the bottom of which there is a visible opening of the outlet channel connecting the veins of the meninges with the external veins of the head. In half of the cases this hole is absent on both sides or on one side. Its width is very variable. The base of the occipital condyle is penetrated by the hypoglossal nerve canal, canalis hypoglossi.
The occipital scales, squama oscipitalis, are triangular in shape, curved, its base faces the occipital foramen, and its apex faces the parietal bones. The upper edge of the scales is connected to the parietal bones through the lambdoid suture, and the lower edge is connected to the mastoid parts of the temporal bones. In this regard, the upper edge of the scales is called lambdoid, margo lambdoideus, and the lower edge is called mastoid, margo mastoideus. The outer surface of the scales is convex, in its middle the external occipital protrusion, protuberantia occipitalis externa, rises, from which the external occipital crest, crista occipitalis externa, intersected in pairs by two nuchal lines, lineae nuchae superior et inferior, descends vertically towards the occipital foramen. In some cases, there is also a higher nuchal line, lineae nuchae suprema. Muscles and ligaments are attached to these lines. The inner surface of the occipital scales is concave, forming in the center the internal occipital protuberance, protuberantia occipitalis interna, which is the center of the cruciform eminence, eminentia cruciformis. This elevation divides the inner surface of the scales into four separate depressions. Adjacent to the top two of them are occipital lobes brain, and to the two lower ones - the cerebellar hemispheres.
Ossification. Starts at the beginning of the 3rd month intrauterine development when islands of ossification appear in both the cartilaginous and connective tissue parts of the occipital bone. Five ossification points appear in the cartilaginous part, of which one is located in the main part, two in the lateral parts and two in the cartilaginous part of the scales. Two ossification points appear in the connective tissue upper part of the scales. By the end of the 3rd month, the upper and lower sections of the scales grow together; in the 3rd-6th year, the main part, lateral parts and scales grow together.

Normal anatomy of man: lecture notes by M. V. Yakovlev

9. STRUCTURE OF THE SKULL. SPHENOID BONE. OCCIPITAL BONE

Scull(cranium) is a collection of tightly connected bones and forms a cavity in which the vital important organs: brain, sensory organs and initial parts of the respiratory and digestive systems. The skull is divided into the brain (cranium cerebrale) and facial (cranium viscerale) sections of the skull.

The brain section of the skull is formed by the occipital, sphenoid, parietal, ethmoid, frontal and temporal bones.

Sphenoid bone (os sphenoidale) is located in the center of the base of the skull and has a body from which processes extend: large and small wings, pterygoid processes.

Body of the sphenoid bone has six surfaces: front, bottom, top, back and two sides. The upper one has a depression - the sella turcica (sella turcica), in the center of which is the pituitary fossa (fossa hypophysialis). Anterior to the recess is the back of the sella, the lateral parts of which form the posterior inclined processes (processus clinoidei posteriores). At the base of the back there is a carotid groove (sulcus caroticus). The anterior surface of the body is elongated into a wedge-shaped crest (crista sphenoidalis), which continues into the keel of the same name. On the sides of the ridge there are sphenoid conchae, which limit the opening of the sphenoid sinus, leading to the sinus of the same name.

Greater wing of the sphenoid bone(ala major) has three openings at the base: round (foramen rotundum), oval (foramen ovale) and spinous (foramen spinosum). The large wing has four surfaces: temporal (facies temporalis), maxillary (facies maxillaries), orbital (facies orbitalis) and cerebral (facies cerebralis), on which arterial grooves and finger-like impressions are located.

Small wing(ala minor) has an anterior inclined process (processus clinoideus anterior) on the medial side. Between the lesser and greater wings there is a space called the superior orbital fissure (fissura orbitalis superior).

Pterygoid process(processus pterigoideus) of the sphenoid bone has lateral and medial plates fused anteriorly. At the back, the plates diverge and form a wing-shaped fossa (fossa pterigoidea). At the base of the process there passes a canal of the same name.

Occipital bone (os occipitale) has a basilar part, lateral parts and scales. Connecting, these sections form the foramen magnum (foramen magnum).

Basilar part(pars basilaris) of the occipital bone has a platform - clivus. The groove of the inferior petrosal sinus (sulcus sinus petrosi inferioris) runs along the lateral edge of this part; there is a pharyngeal tubercle (tuberculum pharyngeum) on the lower surface.

Lateral part(pars lateralis) of the occipital bone has on the lower surface the occipital condyle (condylus occipitalis). The hypoglossal canal (canalis hypoglossalis) runs above the condyles; behind the condyle there is a fossa of the same name, at the bottom of which is the condylar canal (canalis condylaris). Laterally from the condyle there is a jugular notch, limited posteriorly by the jugular process (processus jugularis), next to which the groove of the sigmoid sinus runs.

Occipital scales(squama occipitalis) of the occipital bone has in the center of the outer surface an external occipital protuberance (protuberantia occipitalis externa), from which the crest of the same name descends down. From the occipital protuberance to the right and left there is an upper nuchal line (linea nuchae superior), parallel to which there is a lower nuchal line (linea nuchae inferior). You can distinguish the highest nuchal line (linea nuchae suprema). On the brain surface there is a cruciform eminence (eminentia cruciformis), the center of which is called the internal occipital protuberance, from which the transverse sinus groove (sulcus sinus transverse) runs to the right and left. Upward from the protrusion there is a groove of the superior sagittal sinus (sulcus sinus sagittalis superioris).

From the book Normal Human Anatomy: Lecture Notes author M. V. Yakovlev

10. FRONTAL BONE. PARIETAL BONE The frontal bone (os frontale) consists of the nasal and orbital parts and the frontal scales, which occupy most of the cranial vault. The nasal part (pars nasalis) of the frontal bone on the sides and in front limits the ethmoid notch. The midline of the anterior part of this

From the book Oddities of our body. Entertaining anatomy by Stephen Juan

11. TEMPORAL BONE The temporal bone (os temporale) is the seat for the organs of balance and hearing. The temporal bone, connecting with the zygomatic bone, forms the zygomatic arch (arcus zygomaticus). The temporal bone consists of three parts: the squamosal, the tympanic and the petrous. The scaly part (pars squamosa)

From book Emergency help for injuries, pain shocks and inflammations. Experience in emergency situations author Viktor Fedorovich Yakovlev

12. Ethmoid bone The ethmoid bone (os ethmoidale) consists of the ethmoid labyrinth, ethmoid and perpendicular plates. The ethmoid labyrinth (labyrinthus ethmoidalis) of the ethmoid bone consists of communicating ethmoid cells (cellulae ethmoidales). On the medial side are the upper

From the book Homeopathic Handbook author Sergei Alexandrovich Nikitin

Is it true that we have a “funny bone”? We don’t have a “funny bone,” but we do have a “funny nerve.” This is the ulnar nerve, which controls sensation in the shoulder, forearm, hand and fingers. Most of ulnar nerve hidden deep under the skin, where it is well protected15. However, in

From the book Handbook of Sensible Parents. Part two. Urgent Care. author Evgeny Olegovich Komarovsky

Can you increase your bone size with exercise? Yes, you can. For example, it is known that professional tennis players have a bone density in the hand in which they hold the racket that is 35% higher than the density

From the book Maintenance of the active man's body author Tatiana Bateneva

Why does a broken bone heal so easily? Here's what Dr. Tom Wilson says: “Bones are extremely interesting. They can be thought of as sticks that support the shape of your body, but if you break a stick, there is no way to repair it.” However, the bones are alive, like everything you have

From the book Nature Healing Newsletters. Volume 1 author John Raymond Christopher

The principle of transferring force to the bone Direct impact on the bone includes two aspects: physical and energetic. (The division into aspects is necessary solely for pedagogical purposes.) A noticeable physical force is applied to the bone, leading to its deformation.

From the book Great Protective Book of Health author Natalya Ivanovna Stepanova

Impact on the femur Technique of impact. Place the patient on his side with the lower leg slightly bent at the knee. upper leg half bent at the knee and raised towards the stomach. Place the fixing hand on the knee (patella), the pushing hand on large skewer

From the author's book

Impact on the tibia The technique of impact has two options. The first option. Compression of the bone along the long axis is carried out with a long grip from one end of the bone to the other. The patient's position is on his back with a half-bent position knee joint. Fixing arm

From the author's book

Impact on the fibula Purpose of impact: unloading of the fibula is necessary for hysterical reactions, psychomotor agitation, affects of anger and sadness, the effect on the fibula is especially effective for fears, childhood incontinence

From the author's book

Breastbone Heat and tension in sternum, persistent cough With severe exhaustion- Sanguinaria. Breasts: Burning and shooting pain in the breasts - Laris Albus. Severe soreness and tenderness of the breasts; the patient cannot bear the shaking of the bed; when walking should

From the author's book

6.4.1. FISH BONE ATTENTION! Removing a stuck fish bone yourself is not safe. The bone can damage the larynx or esophagus and may be swallowed and become lodged in the esophagus. If you have the opportunity to see a doctor, do not attempt it on your own.

From the author's book

On-board computer, or why bother - it's a bone The appearance of cars with a computer on board was another technical revolution. Today, a car with “brains” can independently control the quantity and quality of the fuel it fills, the temperature of the coolant

From the author's book

From the author's book

To make a broken bone heal faster right hand with the back facing up at the place where the bone is broken. Say in one breath, with your eyes closed, without moving your lips: A child was born, A man was baptized. Bone white, Bone yellow, You will be born And never again

From the author's book

Speak to the bumps on the arms and legs (grave bone) From the letter: “My sister has a cartilaginous growth growing on her arm. How can I help her get rid of this scourge? I remember that you once published a conspiracy that would help in this case, but I just can’t find it. If there is time,

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