Anatomical structure of the human skull. Skull bones and their joints

Our appearance depends on the structural features of the head. The human cranium is a complex system consisting of different zones that performs various functions. The bones of the skull provide the basis for the face, skeleton, the beginning of the digestive and respiratory systems am. Next, we will consider in detail what bones and zones the human skull consists of.

The human skull is made up of 29 bones. different shapes and size, interconnected by seams. As an exception, the lower jaw stands out.

By the way, the shape of the head directly depends on the structure mandible.

Some cranial bones are hollow, they are connected to the nasal cavity. Due to this structure, the cranium is not heavy, but very durable.

The cranium belongs to the musculoskeletal system and skeletal system. It has two large departments that are responsible for certain areas - this is the facial and cerebral.

Below we consider the anatomy of these two parts of the skull in more detail. In the meantime, let's look at a drawing with a diagram showing an atlas of the human cranium.

Description of the structure of the bones of the cerebral part of the human skull

The brain section includes:

• a pair of temporal;
• a pair of parietals;
• frontal;
• wedge-shaped;
• lattice;
• occipital.

The upper brain part of the skull performs protective function, so the bones here are quite massive.

The wedge-shaped and ethmoid connect the brain and facial sections.

The lateral and upper zones of the cranium are closed by the parietal paired bone, which looks like an irregular quadrangle with a tubercle in the center.

The frontal bone of the skull is unpaired, it connects with the anterior parietal part seams only.

The superciliary arches are located on two frontal tubercles, which are considered part of the scales - the anterior zone.

The eye fossa and nasal part are located on the frontal bone. It covers the ethmoid notch, connects with the nasal passages and the sinus of the same name.

The occipital bone of the cranium forms a vault that covers it from behind and from below.

The foramen magnum has four borders. They form a channel into which nerves, blood vessels, and the spinal cord enter.

Inner and outer tubercles are formed by scales occipital bone.

The base and lateral part are formed by the temporal region. The organs of hearing and balance are located in this zone.

Important! The temporal region consists of the most fragile bones.

This area is formed from several departments:

• scales;
• mastoid part;
• drum;
• pyramid.

A bone that connects to all others is called a sphenoid. Its structure is complex, because it passes through itself nerve endings. The muscles of chewing, eye sockets are attached to this part.

Perforated and orbital plates belong to the ethmoid bone. The orbital plate can be seen with the naked eye, and the perforated one hides behind it and other parts. From the perforated plate, the nasal septum begins to stretch.

The medulla of the skull from a side view is shown in the following figure.

Skull: right side view

The structure of the bones of the facial part of the skull

The facial section includes paired and unpaired bones, which serve as the basis of the skeleton and chewing apparatus. Other bones are smaller in size, they make up the cavity of the facial skull.

The bones of the facial region of the skull are different types, paired and unpaired. There are two jaws - upper and lower. This department includes small bones that form the oral and nasal cavities, eye sockets. The skull has the following structure of the facial section:

Unpaired bones that make up the facial section:

• The vomer is considered a flat bone, looks like a trapezium, forms the nasal cavity together with the ethmoid;
• The only movable area of ​​the skull is the lower jaw. Its main functions are chewing and speech formation. In its structure, it is similar to a horseshoe;
• Under the muscles of the tongue is a horseshoe-shaped bone small sizes, it is called sublingual.

The paired bones that make up the facial section have the names:

• Lacrimal - flat, has the shape of a quadrangle. Partially helps to form the wall of the orbit from the inside, and the nasal cavity from the outside;
• The structure of the upper jaw includes four processes and surfaces, as well as a body. Has a paranasal sinus;
• The structure of the inferior nasal concha includes three processes: ethmoid, nasal and maxillary. It separates the nasal passages - lower and upper;
• Nasal - flat, has the shape of a quadrangle. On the one hand, it is connected to itself by a similar bone, and on the other, by the frontal and ethmoid. due to cartilage tissue;
• The lateral wall of the orbit, as well as the infratemporal fossa, is formed by the zygomatic bone. It is connected to the upper jaw by the process of the same name;
• The back of the nasal cavity and the palate is formed by the palatine bone.

The facial section of the skull in section can be studied from the photo.

In the photo you can see the bones and sutures of a real cranium.

Seams and joints as connective tissue

The sutures of the skull are fibrous. When connecting its parts, only one joint, movable, is isolated - this is the temporomandibular joint.

Thanks to this joint, a person can perform chewing, speech movements. It moves in all directions: sideways, up, down, forward or backward.

In anatomy, the sutures that connect the bones are divided into three types:

• scaly;
• flat;
• jagged.

All parts of the facial section are connected by even, flat seams. The parietal and temporal bones are connected by a scaly suture. The coronal suture unites the parietal and frontal parts. The sutures are clearly visible in the photo of the skull from the back.

Details on how many bones are in the human skull, how they are called in Latin and the layout of their location can be studied in the video for students of medical schools.

Also watch a movie about the anatomy of the bones of the skull.

Functions of the skull

Bone formations act as protective cells for the eye sockets and nasal cavity. In general, they can be considered a kind of framework that protects the senses and the brain.

• Protective function;
• Mimic;
• Chewing;
• Speech education;

Racial features of the structure

There are no identical people on the planet. It is possible to distinguish a person by race not only by skin color or accent. The structure of the skull plays an important role in racial difference. Each race has a specific anatomy, namely:

• Caucasoid (Figure A).

The skeleton of the facial part protrudes strongly forward. The nose is deeply rooted and drawn back a little. Most often, canine pits are strongly developed.

• Mongoloid (Fig. B).

It is also called the Asian-American race. A feature in a large facial angle compared to the Caucasoid. Flatter nasal and zygomatic bones. Shallow landing of the nose. wider. Canine pits are not deep. The cranium consists of large, wide bones, which is reflected in its size.

• Negroid (Figure C).

Moderately. Not a deep landing of the nose, the bones of which are flattened, set wide. The facial angle is less than in previous races.

baby skull

The children's skull has a specific anatomy. With age, its structure changes.

For example, only a born child has fontanelles - loosely closed areas. The most noticeable are considered to be the front and rear. A large fontanel closes closer to 12 months, and a small one - to 1.5.

If the child has even the slightest deviation from the accepted norm of this period, you should contact a specialist.

What are the other features of the children's skull? The sutures in the child's skull are connective tissue. Thanks to this connection, the child moves along birth canal without consequences, and also with the development of the brain grows with it. The sutures completely ossify only at the age of 30. Children's head bones have the ability to change their shape. It grows until the age of 13, stops, while the rest of the bones continue this physiological process.

Sexual differences in the structure of the skull

Anthropometric data distinguish the female structure of the skull from the male. But it is almost impossible to find differences in the skull of a boy and a girl before adolescence.

The structure of the bones of the head of a male person is more massive and large. The front part has a more developed appearance than in women. Women's bone has a lower density, so it is lighter. In most cases, it is generally accepted that sex differences in the structure of the head are only a convention.

Skull shapes

Description of skull shapes:

• the usual form is the cranial index;
• anomaly in the form of a tower - acrocephaly;
• early fusion of sutures - craniostenosis.

"Skull Anatomy"

Head skeleton (skull) is divided into the bones of the brain and facial skull. Inside the skull there is a cavity in which the brain is located.

Bones of the brain skull.

The bones of the cerebral part of the skull include: unpaired - occipital bone, which consists of scales, main and two side parts. This part closes the large occipital foramen. On the lateral parts are condyles that connect the skull with spinal column. frontal bone has scales, nasal part and orbital processes, in the thickness of the bone there is an air cavity. Sphenoid bone consists of the body, large and small wings, pterygoid processes, in the thickness of the body of the sphenoid bone is the sphenoid sinus. On the body of the sphenoid bone, a Turkish saddle with a pituitary fossa is distinguished, to which the pituitary gland is located (part of the brain ). Ethmoid bone consists of a lattice labyrinth, perpendicular and lattice plates. This is an air bone, because. has a large number of lattice cells. Paired bones: parietal bone has a flat quadrangular shape, on the outer surface there is a parietal tubercle; temporal bone consists of a stony part (pyramid), scales and a tympanic part. In the thickness of the pyramid lie the cavities of the middle ear (tympanic cavity) and inner ear(bone labyrinth).

Bones of the facial skull.

There are paired and unpaired bones.

to paired bones relate:

- upper jaw(has a body in the thickness of which lies the air-bearing sinus - maxillary (maxillary), and a number of processes - frontal, zygomatic, palatine, alveolar, which contains alveolar recesses - holes for teeth);

- palatine bone(consists of two plates - horizontal and perpendicular);

- cheekbone(has a number of processes - frontal, temporal, maxillary, with the help of which it is attached to the above bones );

- lacrimal bone;

- nasal bone;

- inferior turbinate.

unpaired bones facial skull are represented by:

lower jaw(has a body and a branch; the body consists of a base and an alveolar part, which contains alveolar holes for teeth; two processes are distinguished on the branch, coronal and condylar. Due to the condylar process, the lower jaw is connected to the temporal bone)

coulter;

hyoid bone.

Joints of the bones of the skull.

The bones of the skull are connected to each other using three types seams: the roof of the skull and its base - using serrated and scaly sutures, and the bones of the facial skull - using flat seams. The largest seams are coronal suture(between the frontal and parietal bones), sagittal suture(between parietal bones) lambdoid seam(between the occipital and parietal bones). There is also a metopic suture (on the frontal bone), it is unstable and ossifies.

In addition to the sutures, the bones of the skull are also connected synchondroses: wedge-occipital synchondrosis (temporary), temporal-sphenoid and temporo-occipital (permanent). And only one bone is movably connected in the skull. This is the lower jaw. The temporomandibular joint is formed (combined, complex, condylar, biaxial).

Skull as a whole.

When studying the skull as a whole, two bases can be distinguished: internal and external.

On the inner base of the skull There are three cranial fossae: anterior(formed by the frontal, ethmoid and sphenoid bones), middle(formed by the sphenoid and temporal bones), back(formed by the occipital and temporal bones).

On the outer base of the skull you can consider such formations as the hard palate (formed by the upper jaw and palatine bone) and three fossae: temporal, infratemporal and pterygo-palatine (they are a receptacle for muscles, blood vessels, nerves, lymph nodes and surrounding adipose tissue).

In the facial region of the skull there are eye socket and nasal cavity.

eye socket has the shape of a pyramid, the top directed backwards; formed by 4 walls: superior, inferior, lateral and medial. Through various openings, the orbit communicates with the nasal cavity, the cranial cavity, the pterygopalatine and infratemporal fossae. Vessels and nerves pass through these openings. The eye socket is a container for the eyeball and its auxiliary apparatus.

nasal cavity has a more complex structure, it is formed by 4 walls and consists of 2 halves, which are separated by the nasal septum (it is formed by the vomer and the perpendicular plastic of the ethmoid bone). Top wall separates the nasal cavity from the cranial cavity, the lateral wall from the cavity of the orbit and the maxillary sinus. The medial wall is the nasal septum, and the lower wall is represented by bones that simultaneously form the hard palate. Thus, the hard palate is both the upper wall of the oral cavity and the lower wall of the nasal cavity. In the nasal cavity on its lateral wall are located three turbinates, under which pass three nasal passages: upper, middle and lower. In addition to these three passages, there is also a common nasal passage.

Age features of the skull:

The skull of a newborn has a number of features:

The dimensions of the bones of the facial skull are smaller than the dimensions of the bones cerebral skull.

Between some bones, at the intersection of the seams, fontanelles (layers of connective tissue) are located. There are anterior, posterior and lateral - wedge-shaped and mastoid fontanelles.

Weak development of the airways in the bones of the skull.

The tubercles, ridges and lines are poorly expressed, as the muscles are poorly developed and have not yet begun to function.

The jaws are poorly developed: the alveolar processes are almost absent, the lower jaw consists of two unfused halves.

In old age, the bones of the skull have a number of features:

In old age, the bones of the skull become thinner and lighter.

As a result of tooth loss, the alveolar edges of the jaws undergo atrophy, as a result of which the face is shortened, the lower jaw protrudes forward.

The seams are ossified.

Sex differences of the skull.

The male skull is on average larger than the female; its capacity is 10% more than the capacity of the female. The surface of the female skull is smoother, as the ridges and lines are less pronounced. The superciliary arches of the female skull are less pronounced than those of the male, and the forehead has a more vertical direction. The eye sockets of the male skull are large, the occipital protuberance protrudes more than that of the female skull. The bones of the male skull are usually thicker.

In this article, you can find out what the areas of the head are, how this part of the body is arranged and why did it even appear during evolution? The article begins with the simplest - basic information about the organization.

What is meant by the skeleton of the head or, more simply, the skull? This is a collection of many bones, paired or not, spongy or mixed. The skull contains only two large sections:

• cerebral (the cavity in which the brain is located);
• facial (this is where some systems originate, such as respiratory or digestive; in addition, here you can find large quantity sense organs).

As for the brain department, it is worth mentioning that this area is also divided into two:

• its foundation.

Evolution

It is important to know that vertebrates did not always have such a large head. Let's dive a little into the past. This part of the body appeared in ancient vertebrates during the fusion of the first three segments of the spine. Prior to this phenomenon, the same segmentation was observed. Each vertebra had its own pair of the first vertebra responsible for smell, the second for vision, and the third for hearing. Over time, the load on these nerves increased, it was necessary to process more and more information, which led to a thickening of these segments responsible for these sensory organs. So they merged into the brain, and the union of the vertebrae formed a brain capsule (like a skull). Note that the head modern man is still divided into segments from which it was formed.

What is the average head size for an adult? Length - 17-22 cm, width - 14-16 cm, height - 12-16 cm, circumference - 54-60 cm. The length of the head, as a rule, is greater than the width, so it is not round, but elliptical. It is also very interesting that the numbers (length, width and height) are not constant, they either increase or decrease. And it all depends on the location of the person.

Brain

Before moving on to studying the areas of the head, it is worth saying that the head is not just considered the most important part of the body. After all, this is where:

• brain;
• organs of vision;
• organs of hearing;
• olfactory organs;
• organs of taste;
• nasopharynx;
• language;
• chewing apparatus.

Now we will learn a little more about the brain. What is it and how is it arranged? This organ is made up of nerve fibers. Neurons (these are brain cells) are able to control the work of the entire human body by generating an electrical impulse. In total, twelve pairs of nerves can be observed that control the functioning of organs. Signals from the brain travel to their destination through the spinal cord.

The brain is constantly in the fluid, which prevents it from contacting the cranium when the head moves. In general, our brain is pretty good protection:

• hard connective tissue;
• soft connective tissue;
• choroid;
• liquor.

The fluid in which our brain "floats" is called cerebrospinal fluid. The pressure of this fluid on the organ is considered to be intracranial pressure.

It is also important that the work of the brain and organs located on the head requires large energy costs. For this reason, we can observe intense blood circulation in this area. It:

1. Nutrition: carotid and vertebral arteries.
2. Outflow: internal and external jugular veins.

So at rest, the head consumes about fifteen percent of the total blood volume of the body.

Skull and muscles

The skeleton of the head (skull) has a no less complex structure. Its main function is to protect the brain from mechanical damage and other external influences.

The entire human cranium is made up of 23 bones. They are all motionless except for one - the lower jaw. As mentioned earlier, there are two divisions here:

• cerebral;
• facial.

Bones related to the facial region (there are 15 in total) can be:

• paired - upper jaw, palatine bone, lacrimal, lower turbinate;
• unpaired - lower jaw, vomer, hyoid.

Paired bones of the brain:

• parietal;
• temporal.

Unpaired:

• occipital;
• frontal;
• wedge-shaped;
• lattice.

Whole brain department in total consists of eight bones.

The cervical region, to which the skull is attached, allows the head to move. Movement is provided by the muscles of the neck. But on the head itself there are also muscle fibers that are responsible for facial expressions, one exception is the masticatory muscles, which are considered the strongest in this area.

Head areas

The whole head is conditionally divided into 13 regions. There are also distinguished paired and unpaired. And so, six of them are classified as unpaired regions.

1. The frontal region of the head (it is the focus of attention in the next section of the article).
2. Parietal (detailed information will be presented to your attention later).
3. Occipital (discussed in more detail in a separate section of the article).
4. Nasal, which fully corresponds to the contour of our nose.
5. Oral, also corresponds to the contour of the mouth.
6. The chin, which is separated from the mouth by the chin-labial groove.

Now we turn to the enumeration of the seven paired regions. These include:

1. The buccal region separated from the nose and mouth by the nasolabial furrow.
2. Parotid-chewing (contours parotid gland and muscles responsible for the chewing reflex).
3. The temporal region of the head (the contours of the scales of the temporal bone, located below the parietal region).
4. Orbital (contour of the eye sockets).
5. Infraorbital (below the eye sockets).
6. Zygomatic (cheekbone contour).
7. Mastoid (this bone can be found behind auricle, which, as it were, covers it).

frontal area

We now turn to a detailed examination of the frontal region of the head. The boundaries of the anterior section are the nasolabial suture, the supraorbital edges, the posterior section is the parietal region, the sides are the temporal region. This department captures even hairy part heads.

As for the blood supply, it is carried out through the following arteries:

• suprablock;
• supraorbital.

They depart from the ophthalmic artery, which is a branch of the carotid. This area has a well developed venous network. All vessels of this network form the following veins:

• suprablock;
• supraorbital.

The latter, in turn, partially flow into the angular, and then into the facial vein. And the other part goes into the eye.

Now briefly about the innervation in the frontal region. These nerves are branches of the eye and have names:

• suprablock;
• supraorbital.

As it is not difficult to guess, they pass together with the vessels of the same name. Motor nerves - branches facial nerve having a name - temporal.

parietal region

This area is limited by the contours of the bones of the crown. You can imagine it if you draw projection lines:

• before - coronal seam;
• back - lambdoid seam;
• sides - temporal lines.

Blood supply is promoted arterial vessels, which are processes of the parietal branches of the temporal artery. Outflow - parietal branch of the temporal vein.

Innervation:

• before - terminal branches of the supraorbital nerve and frontal;
• flanks - ear-vesical nerve;
• back - occipital nerve.

Occipital region

The occipital region of the head is below the parietal, and is limited to the back region of the neck. So the borders:

• top and sides - labd-shaped seam;
• bottom - the line between the tops of the mastoid processes.

Arteries contribute to the blood supply:

• occipital;
• back ear.

Innervation is carried out the following types nerves:

• suboccipital (motor);
• large occipital (sensitive);
• small occipital (sensitive).

Nervous system

The article has already briefly described some areas of the human head. From the table you will learn more detailed information. In total, the head contains 12 pairs of nerves that are responsible for sensations, the release of tears and saliva, the innervation of the muscles of the head, and so on.

Circulatory system

Studying the anatomy of the head, one cannot ignore such a complex, but very important topic as circulatory system. It is she who provides blood circulation to the head, thanks to which a person can live (eat, breathe, drink, communicate, and so on).

For the work of our head, or rather for the brain, a lot of energy is needed, which requires a constant flow of blood. It has already been said that even at rest, our brain consumes fifteen percent of the total volume of blood and twenty-five percent of the oxygen that we receive when breathing.

What arteries supply our brain? Mainly:

• vertebrates;
• sleepy.

Its outflow from the bones of the cranium, muscles, brain, and so on should also occur. This is due to the presence of veins:

• internal jugular;
• external jugular.

arteries

As already mentioned, the vertebral and carotid arteries, which are presented in the form of pairs, are engaged in the nutrition of the human head. The carotid artery is the basis of this process. It is divided into 2 branches:

• external (enriches the outer part of the head);
• internal (passes into the cranial cavity itself and branches, providing blood flow to the eyes and other parts of the brain).

Blood flow to the muscles is carried out externally and internally. carotid artery. About 30% of brain nutrition is carried out vertebral arteries. Basilar provides work:

• cranial nerves;
• inner ear;
• medulla oblongata;
• cervical region spinal cord;
• cerebellum.

The blood supply to the brain varies depending on the individual's condition. Mental or psychophysiological overloads increase this indicator by 50%.

Vienna

Considering the anatomy of the human head, it is hard to pass by a very important topic - venous structure this part of the body. Let's start with what the venous sinuses are. These are large veins that collect blood from following parts:

• skull bones;
• head muscles;
• meninges;
• brain;
• eyeballs;
• inner ear.

You can also find another name for them, namely, venous collectors, which are located between the sheets of the brain membrane. Leaving the cranium, they pass into the jugular vein, which runs next to the carotid artery. You can also distinguish the external jugular vein, which is slightly smaller and located in subcutaneous tissue. This is where blood is collected from:

• eye;
• nose
• chin.

Generally speaking, everything that is listed above is called superficial formations of the head and face.

muscles

In short, all the muscles of our head can be divided into several groups:

• chewing;
• mimic;
• vault of the skull;
• sense organs;
• upper digestive system.

You can guess about the functions performed by their names. For example, chewing makes the process of chewing food possible, but mimics are responsible for human facial expressions, and so on.

It is very important to know that absolutely all muscles, regardless of their main purpose, are involved in speech.

Scull

The whole skull osseous head, divided into two sections:

• facial;
• cerebral.

The first is located between the eye sockets and the chin, and forms the initial sections of some body systems (more specifically, the digestive and respiratory systems). In addition, the facial section is the place of attachment of some muscle groups:

• chewing;
• mimic.

What's in this section:

• eye sockets;
• nasal cavity;
• oral cavity;
• drum cavity.

Particular attention should be paid to the zygomatic bone, which is the place of attachment of the bulk of the muscles of the face. It is located below the orbit and performs an important function - protecting the eye and nose from mechanical damage.

It is important to note the jaw, represented by the upper paired bone and the lower unpaired. The lower jaw is the only movable bone to which strong masticatory muscles are attached.

Let's pay attention to the intermaxillary region, which is also called the deep part of the face. Restrictions:

• the outer part is the branch of the lower jaw;
• inner part- tubercle of the upper jaw;
• top - the lower surface of the large wing of the sphenoid bone.

Briefly about the brain department, which is designed to protect the brain and other structures that are associated with it. The department is formed by 8 bones, the main ones are:

• occipital;
• parietal;
• frontal;
• temporal.

It is important to note that the skull is not solid, it has sinuses and openings that allow nerves and blood vessels to enter the brain. At the base of the skull of the human head is the foramen magnum, which connects the cranial cavity and the spinal canal.

Everyone will agree that the head of every person plays in his life no less important function than the heart. In fact, the human skull is a complex system that has a very interesting structure and performs serious functions. The bones of the head protect the brain and sense organs. Between themselves, they are connected by seams and provide support for the digestive and respiratory systems.

The skull is divided into the facial and brain sections. The bones of the brain part form a cavity for the brain and partly for the sense organs. In addition, they serve as the basis of the face and skeleton of the initial sections of the digestive and respiratory systems. Some cranial bones have cavities that are filled with air. They are connected to the nasal cavity. Due to this structure of the bones, the mass of the skull is not very large, but at the same time, its strength does not become less because of this. The brain skull consists of eight bones: two temporal, two parietal, frontal, sphenoid, ethmoid and occipital bones. Some bones of the facial part of the skull serve as the basis of the skeleton of the masticatory apparatus. Other bones are smaller in size and make up the cavity of the facial skull. Consider the anatomy of these two departments in more detail.

Bones of the cerebral cranial region

So, the brain section consists of eight bones:

• frontal;
• occipital;
• wedge-shaped;
• lattice;
• two temporal;
• two parietal.

The upper part of the cerebral skull is called its vault, in other words, the roof. The lower part is its base. Between the arch and the base there is a conditional line passing through the occipital external protrusion, along the nuchal upper line to the base of the mastoid process. Then the line continues above the auditory external opening, along the base of the zygomatic process and along the crest of the infratemporal view of the main wing of the sphenoid bone. The line reaches the nasofrontal suture along the infraorbital margin.

The anatomy of the cranial vault involves its division into several bones. It is half an ellipsoid in shape. Its long axis is directed to the fronto-occipital part. It corresponds to the longitudinal diameter of the brain box. Two more axes run vertically and transversely. The cranial vault has morpho-functional areas:

• unpaired fronto-parieto-occipital region;
• paired temporal region.

They are separated by temporal lines and differ in relief, mechanical conditions and bone structure. The bones of the arch have a three-layer structure. There is an inner and outer compact plate, which have a diploe between them, that is, a spongy substance. In different areas of the arch, the ratio of compact plates and the thickness of the diploe differs. It all depends on individual variability.

It is proved that the diploe is well developed in the parasagittal zone, where the outer plate is thicker than the inner one. The lateral sections of the arch have an inverse relationship. The diploe is less in the temporal parts.

Structural features of bones determine their strength. Studies have been conducted that have proven that the compression strength of the occipital and parietal bones is greater than that of the frontal bone. The inner plate is more brittle. Even if there are no external injuries, a comminuted fracture of such a plate can occur. This gave reason to call it a vitreous plate.

In the anatomy of the bones of the brain skull importance assigned to spongy bone. There are diploic channels. They contain diploic veins. The following important diploic canals are distinguished in the cranial vault:

• frontal;
• front;
• posterior temporal;
• occipital

Diploic channels are divided according to the functional feature. In this regard, it is possible to distinguish outgoing, depositing and communicating channels. They pass through suture lines in the cranial base. They are able to divide into several branches. In the outer part of the skull, the relief varies individually depending on age and sex.

The inner cranial part has a more complex relief. AT varying degrees brain elevations and finger-like impressions can be expressed. Arterial grooves, branching in a tree-like manner, originate in the cranial base from the spinous foramen. It passes through the meningeal middle artery. Dimples of granulations can be seen in the structure of the inner cranial surface. They are very changeable. In small dimples there are single growths of the arachnoid mater. In large dimples, these growths accumulate.

The base of the skull also has two surfaces - internal and external. The inner surface, as in the case of the cranial vault, reflects the shape of the head. It has indentations and elevations. Three pits are distinguished from the localization.

1. The anterior fossa is the bed frontal lobes hemispheres of the brain. It is formed by the orbital parts of the frontal bone, part of the body of the sphenoid bone, the ethmoid plate and upper surface small wings. In the middle of the wedge-shaped protrusion, there is a border between the middle and anterior fossae.
2. Middle hole. It is formed by the body of the sphenoid bone, the anterior surface of the hard rocky part of the temporal region, small and large wings and lower area scales of the temporal bone. In the middle fossa there are lateral and middle sections. In the lateral sections are the temporal lobes of the hemispheres.
3. Posterior hole. It is mainly formed occipital bone. However, the body of the sphenoid bone and the petrous parts of the temporal bone type take part in this. The posterior fossa contains the cerebellum and brain stem.

There are three sections at the outer base of the skull.

1. The anterior section is connected to the facial bones. It forms the nasal cavities and the roof of the eye sockets.
2. Middle department. It originates at the base of the pterygoid processes and runs to a line that extends through the mastoid processes as well as the anterior margin of the main foramen.
3. Rear section. It is formed by the temporal and occipital bones. It has three areas - mastoid, nuchal and occipital-temporal.

There are many small and large arteries at the base of the skull. Through them pass blood and cranial nerves. The thickness of the bone varies different places. The structure of stronger sections is a system of longitudinal beams converging to the body of the wedge-shaped bone. They are fastened with crossbars running transversely to the borders between the fossae of the skull. The recesses of the cranial fossae have fragile places. It is there that fractures often occur, because the bone is quite thin. In the anterior fossa, injuries form, affecting the cribriform plate. In the middle fossa, fractures transversely pass through the back of the area, which is called the "Turkish saddle". In the posterior fossa, fractures affect the openings, and the top of the pyramid breaks off.

The Turkish saddle is located in the center of the inner base of the skull. In front, it is limited by the tubercle of the saddle. Sloping anterior processes hang over it. Behind it is limited by the back of the saddle. In the center of the saddle there is a pituitary fossa. It is the seat of the pituitary gland, that is, the endocrine gland.

Features of the cranial structure

Of course, the structure of the entire skull is amazing, however, main feature The anatomy of the skull are pneumatic bones containing cells or air sinuses. Most of these sinuses communicate with the nasal cavity and play the role of adnexal cavities. Their role is very important - they have an aerodynamic effect on the inhaled air, so the air stream comes into contact with the olfactory receptors, which are located in the mucous membrane of the nasal cavity, more precisely, in its upper part. The paranasal sinuses are often exposed pathological processes leading to intracranial complications such as brain abscess and meningitis.

There are five main parts.

1. Frontal sinus. This is a steam cavity, which is divided by a septum. Also in this part is the middle nasal passage. The sinus can be located in different places, since its length varies - in the superciliary arches, frontal scales and the orbital part of the frontal type bone. There are single-chamber and multi-chamber sinuses.
2. Sphenoid sinus. Its location is the body of the sphenoid bone. There may be additional partitions in the sinus.
3. lattice cells. Their opening occurs in the middle and upper nasal passages.
4. Mastoid cells. Their message from tympanic cavity occurs through the mastoid cave. Cells may vary in size. There are diploic, compact, mixed and pneumatic mastoid processes.
5. Maxillary sinus. This is the largest accessory cavity of the nose.

The structure of the facial cranial region

The structure of the facial region is associated with the development of the jaws, nasal cavity, digestive and respiratory systems. The speech function also leaves an imprint on this department. Some features of the anatomy of the lower jaw are associated with the muscles that are involved in speech. The facial skull includes three main sections.

1. Orbital-temporal department. This is the orbit, the anterior deepening of the temporal fossa, anterior section cranial middle fossa, pterygopalatine and infratemporal fossa.
2. Nose section. These are the paranasal sinuses, the nasal cavity and the nose itself.
3. Jaw - zygomatic bones, lower and upper jaws.

The upper jaw is an important part of the face and nasal cavity. AT different parts jaw unequal ratio of spongy and compact substance. Alveolar ridge has a powerful layer of spongy substance, from where it passes into the following processes. The frontal process has very small cells of spongy substance. Spongy substance from the zygomatic process goes to the infraorbital region, from where it extends almost to the frontal process. Beams of the spongy substance of the jaw are mainly located at different angles. They are grouped into the lateral and medial systems.

The lower jaw is the solid foundation of the lower facial area. It is she who largely determines the facial shape. Signs of the lower jaw are a decrease in its massiveness, an increase in the angle of the branch, the presence of a chin spine, and so on. The lower jaw is the only movable part of the facial skeleton. Many muscles are attached to it, especially chewing muscles, because the configuration depends on them. The lower jaw is characterized by a basal arch. The channel in which the nerves and blood vessels pass is removed from the dental roots, but there are exceptions. The mental foramen is the exit from the jaw canal. It may be missing on one side, sometimes on both sides. On one side there may be additional holes. The ratio of spongy and compact substance is also not the same in different parts of the jaw. The outer compact plate is thicker than the inner one.

There is also a temporomandibular joint. It is formed articular surfaces head of the jaw, as well as the mandibular fossa of the temporal bone type. These surfaces are covered with fibrous cartilage. There is an articular disc, with the help of which the joint cavity is divided into the lower and upper compartments. It fuses with the joint capsule.

This is a brief excursion into the anatomy of the human skull. As we could see, the head is a complex system consisting of different bones, compounds and other elements. Everything is very interconnected, therefore, if one part of the skull suffers, this affects not only its entire condition, but also the entire body. Therefore, let's protect our heads from all kinds of injuries!

Scull formed by paired and unpaired bones, firmly connected with sutures. It serves as a receptacle and support for vital organs.

In the cavities formed by the bones of the skull, the brain is located, as well as the organs of vision, hearing, balance, smell, taste, which are the most important sense organs. Through numerous holes in the bones of the base of the skull, the cranial nerves exit, and the arteries that feed them pass to the brain and other organs.

The skull consists of two sections: brain and facial. The area in which the brain is located is called brain skull. The second section, which forms the bone base of the face, the initial parts of the digestive and respiratory systems, is called facial skull(Fig. 22, 23).

Rice. 22. The structure of the human skull (side view):

1 - parietal bone, 2 - coronal suture, 3 - frontal bone, 4 - sphenoid bone, 5 - ethmoid bone, 6 - lacrimal bone, 7 - nasal bone, 8 - temporal fossa, 9 - anterior nasal bone, 10 - upper jaw , 11 - lower jaw, 12 - zygomatic bone, 13 - zygomatic arch, 14 - styloid process, 15 - condylar process, 16 - mastoid process, 17 - external auditory canal, 18 - lamdoid suture, 19 - occipital bone, 20 - temporal lines, 21 - temporal bone

Rice. 23. The structure of the human skull (front view):

1 - coronal suture, 2 - parietal bone, 3 - orbital part of the frontal bone, 4 - sphenoid bone, 5 - zygomatic bone, 6 - inferior nasal concha, 7 - upper jaw, 8 - chin protrusion of the lower jaw, 9 - nasal cavity, 10 - vomer, 11 - ethmoid bone, 12 - maxilla, 13 - inferior orbital fissure, 14 - lacrimal bone, 15 - ethmoid bone, 16 - superior orbital fissure, 17 - temporal bone, 18 - zygomatic process of the frontal bone, 19 - optic canal, 20 - nasal bone, 21 - scales of the frontal bone.

The cerebral region of the skull of adults is formed by the frontal, sphenoid, occipital, parietal, temporal and ethmoid bones.

frontal bone unpaired in adults. It forms the anterior part of the brain skull and the upper wall of the orbits. The following parts are distinguished in it: frontal scales, orbital and nasal parts. In the thickness of the bone there is a frontal sinus that communicates with the nasal cavity.

Sphenoid bone located in the center of the base of the skull. She has complex shape and consists of a body from which three pairs of processes extend: large wings, small wings and pterygoid processes. In the body of the bone there is a sinus (sphenoid), which also communicates with the nasal cavity.

Occipital bone forms the posterior-lower part of the brain skull. It distinguishes the main part, lateral masses and occipital scales. All these parts surround a large occipital foramen, through which the brain is connected to the spinal cord.

Parietal bone steam room, forms the upper lateral part of the cranial vault. It is a quadrangular plate, convex outward and concave from the inside.

Ethmoid bone unpaired, participates in the formation of the walls of the orbits and nasal cavity. The following parts are distinguished in it: a horizontally located lattice plate with numerous small holes; perpendicular plate involved in the division of the nasal cavity into the right and left half; ethmoid labyrinths with upper and middle turbinates forming the side walls of the nasal cavity.

Temporal bone steam room. It is involved in the formation of a joint with the lower jaw. In the temporal bone, a pyramid, tympanic and squamous parts are distinguished. A sound-perceiving apparatus is placed inside the pyramid, as well as a vestibular apparatus that detects changes in the position of the body in space. In the pyramid of the temporal bone is the cavity of the middle ear - the tympanic cavity with the auditory ossicles located in it and miniature muscles acting on them. On the lateral surface of the temporal bone there is a hole in the external auditory meatus. The temporal bone is pierced by several canals in which nerves and blood vessels pass (carotid canal for the internal carotid artery, canal of the facial nerve, etc.).

Facial region of the skull. The bones of the facial part of the skull are located under the brain. A significant part of the facial skull is occupied by the skeleton of the chewing apparatus, represented by the upper and lower jaws.

upper jaw - a paired bone involved in the formation of the lower wall of the orbit, the side wall of the nasal cavity, hard palate, openings of the nose - In the upper jaw, a body and four processes are distinguished: frontal, zygomatic, palatine and alveolar, bearing alveoli for the upper teeth.

Lower jaw - the unpaired bone is the only movable bone of the skull, which, connecting with the temporal bones, forms the temporomandibular joints. At the lower jaw, a curved body with alveoli for the lower teeth, coronoid processes for attaching one of the chewing muscles (temporal) and articular processes are isolated.

nasal cavity

The rest, the so-called small bones of the face (paired palatine, inferior nasal concha, nasal, lacrimal, zygomatic, and unpaired vomer) are small in size, are part of the walls of the orbits, nasal and oral cavity. The bones of the skull also include an arcuately curved hyoid bone, which has paired processes - the upper and lower horns.

Joints of the bones of the skull. All bones of the skull, with the exception of the lower jaw and hyoid bone, are fixedly connected to each other with sutures. For ease of study, the brain skull is isolated upper part – vault, or skull roof, and lower part – base of skull.

Skull roof bones connected by continuous fibrous connections - seams, bones of the base of the skull form cartilaginous joints - synchondrosis. The frontal, parietal, and occipital bones form jagged sutures; the bones of the facial skull are joined by flat, harmonious sutures. The temporal bone is connected to the parietal and sphenoid bones with a scaly suture. AT adulthood at the base of the skull, cartilaginous joints are replaced by bone tissue - adjacent bones fuse with each other.

The lower jaw forms a pair with the temporal bone temporomandibular joint. The articular process of the lower jaw and the articular surface on the temporal bone participate in the formation of this joint. This joint is ellipsoid in shape, complex in structure, combined in function. Inside the joint there is an intra-articular disc, fused along the periphery with the joint capsule and dividing the articular cavity into two floors: upper and lower. The temporomandibular joint performs the following movements: lowering and raising the lower jaw, moving the jaw to the sides, moving the lower jaw back and forth.

The skull has a complex relief of both the outer and inner surfaces, due to the location in its bone cavities of the brain (cranial cavity), organs of vision (eye sockets), smell (nasal cavity), taste (mouth cavity), hearing and balance (tympanic cavity). and labyrinths of the inner ear).

In the front of the skull (100. Fig. 23) are located eye sockets, in the formation of which the upper jaws, frontal, zygomatic, sphenoid and other bones participate. Above the eye sockets is the anterior surface of the frontal bone with superciliary arches. Between the eye sockets is the bony dorsum of the nose, formed by the nasal bones, and below is the anterior opening (aperture) of the nasal cavity. Even lower, arcuate alveolar processes of fused maxillary bones and lower jaw with teeth located in the alveoli are visible.

nasal cavity, which is the bone skeleton of the beginning of the respiratory tract, has an inlet (aperture) in front, and two outlets in the back - choanae. The upper wall of the nasal cavity is formed by the nasal bones, the ethmoid plate of the ethmoid bone, the body of the sphenoid bone and the frontal bone. The lower wall is represented by the upper surface of the bony palate. On the side surfaces formed by the maxillary and other bones, three curved plates are visible - the upper, middle and lower nasal conchas.

On the lateral surface of the skull (see Fig. 22) is visible zygomatic arch, which connects the zygomatic bone anteriorly to the temporal bone posteriorly and external auditory meatus with the mastoid process located behind it directed downwards. Above the zygomatic arch is a recess - temporal fossa, where the temporal muscle originates, and below the arc - deep infratemporal fossa, as well as processes of the lower jaw.

In the back of the skull, the external occipital protrusion protrudes posteriorly.

Inferior surface of the skull has a complex terrain. Ahead is solid sky, bounded in front and on the sides by an alveolar arch with upper teeth. Behind and above the hard palate are visible choanae - posterior openings of the nasal cavity, communicating this cavity with the pharynx. On the lower surface of the occipital bone there are two condyles for connection with the I cervical vertebra, and between them - large foramen magnum. On the sides of the occipital bone, a complex relief of the lower surface of the temporal bones is visible with openings for the passage of nerves and blood vessels, the articular fossa and anterior to it a tubercle for articulation with the articular processes of the lower jaw.

Inner surface of the base of the skull has a relief corresponding to the lower surface of the brain. Three cranial fossae are visible here - anterior, middle and posterior. In the anterior cranial fossa, formed by the frontal and ethmoid bones, the frontal lobes of the brain are located. The middle cranial fossa is formed by the sphenoid and temporal bones. It contains the temporal lobes of the brain, and in the pituitary fossa - the pituitary gland. In the posterior cranial fossa, bounded by the occipital and temporal bones, are the cerebellum and the occipital lobes of the brain.