Individual bones of the skull. Human anatomy: structure of the skull parts

Skull (cranium) only partly relates to the musculoskeletal system. It primarily serves as a receptacle for the brain and its connections; in addition, it surrounds the initial part of the digestive and respiratory tracts, which open outward. Accordingly, the skull in all vertebrates is divided into two parts: the cerebral skull, neurocranium, and the visceral skull, cranium viscerale.

In the brain skull there is a distinction between the vault, calvaria, and the base, basis.

Development of the skull. The skull, like the skeleton of the head, is determined in its development by the above-mentioned organs of the animal and plant life. The cranium develops in connection with the brain and sensory organs. Animals without a brain do not have brain skull. In chordates (lancelet), in which the brain is in its infancy, it is surrounded by a connective tissue membrane (membranous skull).

With the development of the brain in fish, a protective box is formed around the latter, which cartilaginous fish(sharks) acquires cartilaginous tissue (cartilaginous skull), and in teleosts - bone tissue (the beginning of the formation of a bone skull). With the emergence of animals from water to land (amphibians), further replacement occurs cartilage tissue bone, necessary for protection, support and movement in conditions of terrestrial existence. In other classes of vertebrates, connective and cartilaginous tissues are almost completely replaced by bone tissue, and bony skull, characterized by greater strength. The development of individual bones of the skull is also determined by the same factors. This explains the relatively simple structure of the bones of the cranial vault (for example, the parietal) and the very complex structure of the bones of the base, for example the temporal, which is involved in all functions of the skull and is a container for the organs of hearing and gravity.

In terrestrial animals, the number of bones decreases, but their structure becomes more complex, because a number of bones are the product of fusion of previously independent bone formations.

In mammals, the brain skull and visceral skull are closely fused with each other. In humans, due to the greatest development of the brain and sensory organs, the neurocranium reaches a significant size and predominates over the visceral skull.

The visceral skull develops from the material of paired gill arches enclosed in the lateral walls of the head section of the primary intestine. In lower vertebrates living in water, the gill arches lie metamerically between the gill slits through which water passes to the gills, which are aquatic respiratory organs. The I and II branchial arches are divided into dorsal and ventral parts. Develops (partially) from the dorsal part of the first arch upper jaw, and the ventral part of the first arch takes part in the development lower jaw. Therefore, in the first arc a distinction is made between processus maxillaris and processus mandibularis.

As animals emerge from the water onto land, the lungs gradually develop, i.e., air-type respiratory organs, and the gills lose their importance. In this regard, gill pouches in terrestrial vertebrates and humans are present only in the embryonic period, and the material of the gill arches is used to build facial bones.

Thus, driving forces The evolution of the head skeleton is the transition from aquatic to terrestrial life (amphibians), adaptation to living conditions on land (other classes of vertebrates, especially mammals) and highest development the brain and its tools - the senses, as well as the appearance of speech (man). Reflecting this line of evolution, the human skull in ontogenesis goes through 3 stages of development:

connective tissue,
cartilaginous and
bone.

The transition of the second stage to the third, i.e. the formation of secondary bones on the basis of cartilage, lasts throughout a person’s life. Even in an adult, remnants of cartilaginous tissue between the bones are preserved in the form of their cartilaginous joints (synchondroses). The cranial vault, which serves only to protect the brain, develops directly from the membranous skull, bypassing the cartilage stage. Transition connective tissue in the bone here also occurs throughout a person’s life. Remains of non-ossified connective tissue are preserved between the bones of the skull in the form of fontanelles in newborns and sutures in children and adults.

Brain skull representing continuation spinal column, develops from the sclerotomes of the cephalic somites, which are formed in 3-4 pairs in the occipital region around the anterior end of the chorda dorsalis. The mesenchyme of the sclerotomes, surrounding the brain vesicles and developing sensory organs, forms a cartilaginous capsule, cranium primordiale (original), which, unlike the spinal column, remains unsegmented. The notochord penetrates the skull up to the pituitary gland, hypophysis, as a result of which the skull is divided in relation to the notochord into notochordal and prechordal parts. In the prechordal part in front of the pituitary gland, another pair of cartilages, or cranial crossbars, trabeculae cranii, are laid, which are in connection with the cartilaginous nasal capsule lying in front, enclosing the olfactory organ. On the sides of the notochord there are cartilaginous plates called parachordalia. Subsequently, trabeculae cranii fuse with parachordalia into one cartilaginous plate, and parachordalia - with cartilaginous auditory capsules, enclosing the rudiments of the hearing organ. Between the nasal and auditory capsules on each side of the skull there is a recess for the organ of vision.

Reflecting evolutionary fusion into larger formations, the bones of the skull base arise from separate bony formations (formerly independent) that fuse together to form mixed bones. The cartilages of the gill arches are also transformed: the upper part (of the first gill arch or jaw arch) is involved in the formation of the upper jaw. On the ventral cartilage of the same arch, the lower jaw is formed, which is attached to the temporal bone through the temporomandibular joint. The remaining parts of the cartilage of the gill arch turn into auditory ossicles: the malleus and the incus.

The upper section of the second branchial arch (hyoid) goes to the formation of the third auditory ossicle - the stapes. All three auditory ossicles are not related to the bones of the face and are placed in tympanic cavity, developing from the first gill pouch and constituting the middle ear. The rest of the hyoid arch goes to build the hyoid bone (lesser horns and partly the body) and the styloid processes of the temporal bone along with the lig. stylohyoideum.

The third branchial arch gives rise to the remaining parts of the body of the hyoid bone and its big horns. From the remaining branchial arches come the cartilages of the larynx, which are not related to the skeleton.

Thus, in humans, the bones of the skull can be divided into 3 groups according to their development.

Bones forming the brain capsule:

developing on the basis of connective tissue - bones of the vault: parietal, frontal, upper part of the scales of the occipital bone, scales and tympanic part of the temporal bone;

developing on the basis of cartilage - bones of the base: the sphenoid (with the exception of the medial plate of the pterygoid process), the lower part of the scales, the basilar and lateral parts of the occipital bone, the petrous part of the temporal bone.

Bones developing in connection with the nasal capsule:

Bones developing from gill arches:

Bones that developed from brain capsule, form the brain skull, and the bones of the other two sections, with the exception of the ethmoid, form the bones of the face. Due to strong development In humans, the cranial vault, which rises above the rest of the brain, is very convex and rounded. This feature sharply distinguishes the human skull from the skulls of not only lower mammals, but also great apes, a clear proof of which can be the capacity of the cranial cavity. Its volume in humans is about 1500 cm3, in apes it reaches only 400-500 cm3. The fossil ape-man (Pithecanthropus) has a skull capacity of about 900 cm3.

The skeleton of the head is represented by bones, which, tightly connected by sutures, protect the brain and sensory organs from mechanical influences. It provides support to the face, the initial parts of the respiratory and digestive systems

Scull(cranium) is divided into two sections - cerebral and facial. The bones of the cranium form a cavity for the brain and partially a cavity for the sensory organs. The bones of the facial skull make up bone base faces and skeleton of the initial parts of the respiratory and digestive systems. The bones of the brain skull include eight bones: two doubles - temporal and parietal and four unpaired- frontal, ethmoid, sphenoid and occipital.

Part of the bones of the facial skull makes up the skeleton masticatory apparatus: paired maxillary bone and unpaired lower jaw. Other facial bones are smaller. This paired dice: palatine, nasal, lacrimal, zygomatic, inferior nasal concha, to unpaired include vomer and hyoid bone.

Frontal bone participates in the formation of the anterior part of the cranial vault and the anterior cranial fossa: The frontal bone consists of the frontal scales, orbital and nasal parts. The frontal scales are involved in the formation of the cranial vault. On convex outer surface of the frontal bone there are paired projections - frontal tubercles, and lower - brow ridges. Flat surface between brow ridges called glabella (glabella).

Parietal bone - a paired plate that forms the middle part of the cranial vault. It has a convex (outer) and concave (inner) surface:

The upper (sagittal) edge connects to the opposite parietal bone, the anterior (frontal) and posterior (occipital) - respectively to the frontal and occipital bones. The scales of the temporal bone (squamosal bone) are superimposed on the lower edge of the parietal bone. Relief inner surface parietal bone is caused by adjacent hard meninges and its vessels.

Occipital bone(os occipitale) consists of a basilar and two lateral parts, the occipital scales: They surround the foramen magnum, through which the cranial cavity connects with spinal canal. Anterior to the foramen magnum is the main (basilar) part of the occipital bone, which, fused with the body of the sphenoid bone, forms a slightly inclined surface - slope

On the lower surface of the lateral (lateral) parts there is occipital condyle, serving to connect to I cervical vertebra. Basilar and lateral parts and lower sections occipital scales participate in the formation of the base of the skull ( posterior fossa), where the cerebellum and other brain structures are located.

The occipital scales are involved in the formation of the cranial vault. In the center of its inner surface there is a cruciform eminence, which forms the internal occipital protrusion. The serrated edge of the scales is connected to the lambdoid suture. parietal and temporal bones.

Ethmoid bone together with other bones takes part in the formation anterior section the base of the skull, the walls of the orbits and the nasal cavity of the facial part of the skull.

The bone consists of a cribriform plate, from which a perpendicular plate extends downward, participating in the formation of the septum of the nasal cavity. On both sides of the perpendicular plate there are lattice labyrinths consisting of air cells. There are three pairs of cells of the ethmoid bone that connect to the nasal cavity: anterior, middle and posterior.

Sphenoid bone located between the frontal and occipital bones and is located in the center of the base of the skull: This bone is shaped like a butterfly. It consists of a body and three paired processes: large and small wings and pterygoid processes. On top surface the body of the bone contains a depression (sella turcica) in which the main gland is located internal secretion - pituitary. In the body of the sphenoid bone there is a sinus that connects to the nasal cavity. Two small wings extend to the sides from the anterosuperior surface of the sphenoid bone; at the base of each there is a large opening of the optic canal, through which the optic nerve. Between the lesser and greater wings there is the superior orbital fissure, through which the oculomotor, lateral, abducens and ophthalmic nerves pass from the cranial cavity into the orbit - branch I trigeminal nerve.

Temporal bone - a paired bone, part of the base of the skull and the lateral part of the cranial vault, connected in front with the sphenoid, in the back with the occipital and above with the parietal bones. The temporal bone is receptacle for the organs of hearing and balance, vessels and nerves pass through its channels. With the lower jaw, the temporal bone forms a joint, and with the zygomatic bone, the zygomatic arch.

On the inner surface of the scaly part there are finger-like impressions and cerebral elevations, and a trace of the middle meningeal artery is visible.

On the outside convex surface The scaly part, slightly higher and anterior to the external auditory opening, begins the horizontally located zygomatic process. At the base of the latter there is a mandibular fossa, with which the condylar process of the mandible forms a joint.

Pyramid (rocky part) The temporal bone has a triangular shape. Posterior to the external opening of the carotid canal, the jugular fossa is visible, which in the region of the posterior edge of the pyramid passes into the jugular notch. The jugular notches of the temporal and occipital bones, when they are connected, on the whole skull form a jugular foramen through which the internal jugular vein and three cranial nerves: glossopharyngeal, vagus and accessory.

In the pyramid of the temporal bone there are carotid and facial canals, as well as the canaliculus of the chorda tympani, the tympanic canaliculus, the mastoid canaliculus, the carotid-tympanic canaliculi, in which the vessels, nerves and muscle that tensor the tympanic membrane are located._______________________________________________________

ANOTHER OPTION!!!

The skull is a collection of tightly joined bones and forms a cavity in which vital organs are located.

The brain section of the skull is formed by the occipital, sphenoid, parietal, ethmoid, frontal and temporal bones.The sphenoid bone 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.The body of the sphenoid bone has six surfaces: anterior, inferior, superior, posterior and two lateral.The large wing of the sphenoid bone has three holes at the base: round, oval and spinous.The lesser wing has an anterior inclined process on the medial sideThe pterygoid process of the sphenoid bone has lateral and medial plates fused anteriorly.

Occipital bone has a basilar part, lateral parts and scales. Connecting, these sections form the foramen magnum.The lateral part of the occipital bone has an occipital condyle on its lower surface. The hypoglossal canal runs above the condyles; behind the condyle there is a fossa of the same name, at the bottom of which is the condylar canal.The occipital squama of the occipital bone has in the center of the outer surface an external occipital protrusion from which the crest of the same name descends downwards.

Frontal bone consists of the nasal and orbital parts and the frontal scales, which occupy most of the cranial vault. The nasal part of the frontal bone limits the ethmoid notch on the sides and in front. The midline of the anterior section of this part ends with the nasal spine, to the right and left of which is the aperture of the frontal sinus, which leads to the right and left frontal sinuses. Right part the orbital part of the frontal bone is separated from the left ethmoid notch

Parietal bone has four edges: occipital, frontal, sagittal and squamous. The parietal bone forms the upper lateral vaults of the skull.

Temporal bone is a receptacle for the organs of balance and hearing. The temporal bone, connecting with the zygomatic bone, forms the zygomatic arch. The temporal bone consists of three parts: squamosal, tympanic and petrous.

The ethmoid bone consists of the ethmoid labyrinth, the ethmoidal plate and the perpendicular plate.The ethmoidal labyrinth of the ethmoid bone consists of communicating ethmoid cells.

Protective and support functions. It protects against mechanical damage the brain, organs of vision, hearing, smell, serve as a support for the soft parts of the head and the attachment point for facial muscles.

What are the different divisions in the skull?

There are two sections: the brain and the facial. The brain is located in the medulla. Unpaired frontal and occipital bones and paired parietal and temporal bones form top part brain section - cranial vault.

The bones that form the cranial vault are flat bones and perform a primarily protective function.

The base of the brain section of the skull is formed by the sphenoid bone and the pyramidal processes of the temporal. The pyramidal processes contain hearing receptors and vestibular apparatus.

What bones belong to the facial part of the skull?

The facial region includes the upper and lower jaws, zygomatic and nasal bones, and the ethmoid. The ethmoid bone, which determines the shape of the nasal cavities, contains the organ of smell.

All bones of the brain and facial parts of the skull, with the exception of the lower jaw, are fixedly connected to each other. They cannot move relative to each other, while the lower jaw can move up and down, left and right and back and forth. Thanks to this property, a person is able to speak clearly and chew food.

Chemical composition of skull bones

All bones consist of organic and inorganic substances: the former are responsible for the elasticity of the bone and its ability to change its shape (to be flexible), the latter for its strength and hardness. It is the combination of a hard but brittle inorganic substance and an elastic organic substance that makes the bone strong and elastic at the same time.

With age mineral matter there is more in the bones, therefore their fragility and susceptibility to fractures increases. Children's bones rarely break, but they are more easily deformed when there is an uneven load on them.

How many bones are in the skull

The human skull consists of 23 bones, not including the auditory bones.

Structure of any part human body begins with the bone frame, and therefore the anatomy of the head debuts with the skull, as a complex of bones that form the basis on which the soft fabrics and in which the organs are placed. In the structure (anatomy) of the human skull, there are 23 main bones that form the skull itself, teeth of the upper and lower jaws, the number of which depends on the age of the dentition, and 3 pairs auditory ossicles related to the middle ear.

Inside the cranium are the brain, sensory organs and upper sections respiratory and digestive organs. Due to the peculiarities of the anatomy of the skull, the organs inside it are protected ( protective function skull), they are correctly placed and fixed (support function) and the entire organ system has the ability to move correctly and interact with other organs and systems (motor function).

Anatomy of the cerebral part of the skull: photo and diagram of the vault

In the anatomy of the human skull, the following sections are distinguished: the external and internal bases of the skull, the nasal cavity and orbit, the bony palate, the pterygopalatine, temporal and infratemporal fossae.

In this diagram, the anatomy of the human skull is a front and side view, the visualized bones are indicated in color:

Based on functionality, the skull is divided into the cerebral and facial (visceral) parts of the skull. In humans, the cerebral region in volume prevails over the visceral region, which is explained by the size of the brain. Its size, the addition of the speech function and changes in nutritional habits formed a reduced masticatory apparatus.

The photo shows the anatomy of the human skull in comparison with the skulls of other mammals: it is obvious that the front part of the human skull is flatter, and its volume is much larger:

In the anatomy of the brain skull, the following sections are distinguished: the vault (roof) of the skull made of flat bones and the base of the skull made of bones mixed type.

The anatomy of the cranial vault in children is very different from that in adults, because in utero the vault is a soft membrane that partially ossifies by the end of pregnancy.

In the anatomy of the brain section of the skull, 4 unpaired bones (frontal, occipital, sphenoid and ethmoid) and 2 paired (parietal and temporal).

The cranial vault is a firmly bonded bone frame, in which the frontal bone (scales), parietal and temporal bones and the upper parts of the occipital and large wings of the sphenoid bones are distinguished. Between these bones there are three sutures: between the frontal and parietal bones - the coronoid, between the parietals - sagittal (sagittal), and between the occipital and parietal bones - lambdoid.

Anatomy of the external and internal base of the skull: foramina and fossae

A feature of some bones of the base of the skull is their pneumatization: they contain air sinuses, taking part in the respiratory process, the processes of smell, vocal resonance and baroreception. In the anatomy of the base of the skull, a distinction is made between the external and internal bases, the structure of which is very complex, but provides the most important needs of the body.

Anatomy of the external base of the skull: it is formed by the base of the occipital bone scales, part of the temporal bone (its scales, tympanic part and bottom pyramids), the lower surface of the sphenoid bone, and in front - the bony palate. In front it is overlapped by the bones of the facial part of the skull. The most important features This area of the skull is its openings (laceated, oval, spinous, jugular and stylomastoid), fossae (scaphoid, mandibular and jugular), processes (styloid and mastoid) and one of the most important canals in the body - the carotid.

In the center of the base is the largest of the openings in the anatomy of the skull - the foramen magnum (foramen magnum), through which spinal cord, which is a continuation of the brain, exits the cranial cavity into the spinal canal.

The internal base of the skull is an uneven surface adjacent to the brain below, consisting of the anterior, middle and posterior cranial fossae containing structures big brain and cerebellum. The boundaries between the fossae are the bony protrusions of the sphenoid and temporal bones.

The anterior cranial fossa is separated from the middle by the posterior edges of the lesser wings of the sphenoid bone and is formed by the surfaces of the frontal, ethmoid and sphenoid bones. The contents of the pit are frontal lobes brain, and from it are discharged outward from the fossa olfactory nerves, the nerve of the first branch of the trigeminal nerve and a pair of vessels (ethmoidal artery and vein).

The middle cranial fossa is separated from the posterior superior face of the pyramids of the temporal bones. The lateral parts of the fossa are formed by the anterior surfaces of the pyramids and temporal bones, and middle part The fossa is the area of the pituitary gland (sella turcica) along the upper surface of the body of the sphenoid bone. The contents of the lateral parts of the pit are temporal lobes, and the middle part is the pituitary gland. In front of it there is a chiasm of the optic nerves, on the sides there are cavernous sinuses with venous blood from the ophthalmic veins.

The optic nerve and ophthalmic artery exit from the fossa into the orbit through the optic canal, as well as the oculomotor, trochlear, abducens and optic nerves and ophthalmic veins through the orbital fissure. IN pterygopalatine fossa The maxillary nerve emerges from the middle cranial fossa through the foramen rotundum. The mandibular nerve enters the infratemporal fossa through the foramen ovale and the middle meningeal artery through the foramen spinosum. The internal cavity enters the cranial cavity carotid artery through a torn hole.

The posterior cranial fossa is formed occipital bone and, partially, the sphenoid, temporal and parietal bones. The contents of the fossa are represented by the cerebellum, and in addition there is the foramen magnum, through which the medulla And vertebral arteries. From the fossa, through the internal auditory opening, the facial, intermediate and vestibulocochlear nerves emerge. Through the jugular openings are the glossopharyngeal, vagus and accessory nerves and the internal jugular vein, and in the lateral sections, in the corresponding canals, the hypoglossal nerves are located.

On this photo Anatomy of the skull in section (on a corpse in the anatomical theater), the structures of the internal base of the skull are visible: anterior, middle and posterior cranial fossae:

Anatomy of the head: sphenoid and occipital bones of the skull

As mentioned above, in the anatomy of the human skull, bones are paired and unpaired, and the brain and facial sections are distinguished in the skull.

So, unpaired bones of the medulla:

The frontal bone forms the anterior surface of the vault and the anterior cranial fossa of the base of the skull. It has 4 parts: scales, 2 orbital parts and a nasal part between them. Contains the air-bearing paranasal sinus of the same name.
The ethmoid bone has a characteristic cellular structure, which is why it received its name. Located between the cranial and nasal cavities in the middle, between frontal bone and the upper jaw, anterior to the sphenoid bone.
Among other bones, the anatomy of the sphenoid bone in the skull is considered one of the most complex. It has a body, 2 pairs of wings (large and small) and pterygoid processes. In its body it has the air-bearing paranasal sinus of the same name.
There is a direct connection between the attachment of the spine to the skull and the anatomy of the occipital bone, since it forms an articulation with the atlas (the first cervical vertebra). In this regard, it develops from cartilaginous and membranous tissues simultaneously, which causes the separation of 4 parts in it: basilar in front, scales in the back and 2 lateral parts. Forms the posterior cranial fossa.

The structure of the paired bones of the human skull in the anatomy of the brain allows them to form strong support and protection for the brain thanks to only 2 pairs of bones:

The parietal bones are simple in their structure and form the main lateral parts of the arch. They are separated from each other by a sagittal suture, and also border on the frontal, occipital, temporal and sphenoid bones.
The temporal bone, one of the most complex bones, is also important as the structure of the hearing organ and vestibular apparatus. Rich in nerves and their nodes, the internal carotid artery passes through it.

Anatomy of the bones of the facial part of the skull

In the anatomy of the facial part of the skull, the bones are of a mixed type and the largest of them are the upper and lower jaws, and the smaller ones complement them, forming the orbits, nasal and oral cavities.

In the anatomy of the bones of the facial skull, there are 3 unpaired bones:

The vomer forms together with the ethmoid bone nasal septum, has the shape of a trapezoid and belongs to flat bones.
The lower jaw is the only movable bone in the skull; it performs the function of chewing and takes part in speech formation. It has the shape of a horseshoe.
The hyoid bone is a small horseshoe-shaped bone located under the tongue muscle.

Paired facial bones:

The lacrimal bone is a quadrangular flat bone that partially forms inner wall the orbit and the outer nasal cavity.
The upper jaw consists of a body, 4 processes and 4 surfaces. Contains the air-bearing paranasal (maxillary) sinus of the same name.
The inferior nasal concha separates the lower and middle nasal passages, has a body and 3 processes: the lacrimal, maxillary and ethmoid.
The nasal bone is a quadrangular flat bone that connects with its paired bone on one side and the frontal and ethmoid bones on the other. Together with cartilaginous part shapes the nose.
The zygomatic bone forms part of the lateral wall of the orbit and infratemporal fossa and forms the zygomatic arch, connecting with the process of the same name of the upper jaw.
The palatine bone is a flat bone that forms the hard palate and back nasal cavity.

Anatomy of the joints of the skull bones: sutures and joints

In the anatomy of the joints of the skull bones, the only movable temporomandibular joint and a mass of fibrous sutures are distinguished.

The temporomandibular joint provides the possibility of acts of chewing and speech precisely due to its wide range Possible movements: up and down, back and forth and to the sides.

The remaining bones of the skull are connected by sutures, the anatomy of which divides them into 3 types: flat, scaly and serrated. Flat seams have smooth edges and connect the bones of the face. The scaly suture runs between the edges of the parietal and temporal bones. The serrated sutures are located between the frontal and parietal bones (coronal suture), parietal and occipital (lambdoid) and between the parietal (sagittal or sagittal).

Below the video demonstrates the anatomy of the skull bones in detail: sutures and joints, places of contact of blood vessels, pits and openings:

Anatomy of a newborn baby's skull

You will be interested to know that the brain part of the skull in a newborn is much larger than the facial part, and its volume exceeds the volume of the facial part by 8 times (in infants, the bones of the upper and lower jaws are greatly underdeveloped). Between some of the bones of the medulla there are connective tissue membranes - fontanelles, which facilitate the passage of the head through the narrow birth canal mother, and also provide space for the growing brain.

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

The cavities formed by the bones of the skull contain the brain, as well as the organs of vision, hearing, balance, smell, and taste, which are the most important sense organs. Through numerous holes in the bones of the base of the skull emerge cranial nerves, and the arteries feeding them pass to the brain and other organs.

The skull consists of two sections: the brain and the facial. The section 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, got the name facial skull(Fig. 22, 23).

Rice. 22. 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. 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 - upper jaw, 13 - lower 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 - squama of the frontal bone.

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

Frontal bone in adults, unpaired. It forms the anterior part of the cranium and the upper wall of the orbits. It distinguishes the following parts: 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. It has a 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-inferior part of the brain skull. It consists of a main part, lateral masses and occipital scales. All these parts surround the foramen magnum, through which the brain connects to the spinal cord.

Parietal bone steam room, forms the upper lateral section of the cranial vault. It is a quadrangular plate, convex from the outside 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 having numerous small holes; perpendicular plate involved in dividing the nasal cavity into right and left half; ethmoid labyrinths with the superior and middle nasal conchae, forming the lateral walls of the nasal cavity.

Temporal bone steam room It participates in the formation of the joint with the lower jaw. The temporal bone is divided into pyramid, tympanic and squamosal parts. Inside the pyramid there is a sound-receiving apparatus, as well as a vestibular apparatus that detects changes in the position of the body in space. In the pyramid of the temporal bone there is the cavity of the middle ear - the tympanic cavity with the auditory ossicles located in it and the miniature muscles acting on them. On the lateral surface of the temporal bone there is an opening for the external auditory canal. 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 part 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 masticatory apparatus, represented by the upper and lower jaws.

Upper jaw – paired bone involved in the formation of the lower wall of the orbit, the lateral wall of the nasal cavity, hard palate, openings of the nose - The upper jaw has a body and four processes: frontal, zygomatic, palatine and alveolar, which bears 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. The lower jaw has a curved body with alveoli for the lower teeth, coronoid processes for attaching one of the masticatory muscles (temporal) and articular processes.

Nasal cavity

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

Connections 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 using sutures. For ease of study, the upper part of the brain skull is isolated - vault, or roof of the skull And bottom part – base of skull.

Skull roof bones connected by continuous fibrous connections - seams, the 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 connected using flat, harmonious sutures. The temporal bone is connected to the parietal and sphenoid bones using a scaly suture. IN mature age at the base of the skull, cartilage joints are replaced by bone tissue - neighboring bones grow together.

The lower jaw forms a pair with the temporal bone temporomandibular joint. The formation of this joint involves the articular process of the lower jaw and the articular surface on the temporal bone. This joint is ellipsoidal in shape, complex in structure, combined in function. Inside the joint there is an intra-articular disc, fused along the periphery with the articular 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, shifting the lower jaw back and forth.

The skull has a complex topography of both the outer and inner surfaces, due to the location in its bony cavities of the brain (cranial cavity), organs of vision (orbit), smell (nasal cavity), taste (oral cavity), hearing and balance (tympanic cavity and labyrinths of the inner ear).

In the front part of the skull (art. Fig. 23) there are 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 the brow ridges. 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, arched alveolar processes of the fused maxillary bones and lower jaw with teeth located in the alveoli are visible.

nasal cavity, which is the bony skeleton of the beginning of the respiratory tract, has an inlet opening (aperture) in front, and two outlet openings in the back - choanae. The upper wall of the nasal cavity is formed by the nasal bones, the cribriform 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 lateral surfaces formed by the maxillary and other bones, three curved plates are visible - the upper, middle and lower turbinates.

On the lateral surface of the skull (see Fig. 22) visible zygomatic arch, which connects the zygomatic bone in front with the temporal bone in the back and external auditory canal with the mastoid process located behind it, directed downward. Above the zygomatic arch there is a depression - temporal fossa, where the temporal muscle originates, and below the arch - deep infratemporal fossa, as well as the processes of the lower jaw.

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

Lower surface of the skull has a complex terrain. Ahead is solid sky, bounded anteriorly and laterally by the alveolar arch with the upper teeth. Visible behind and above the hard palate choanae – the posterior openings of the nasal cavity, connecting this cavity with the pharynx. On the lower surface of the occipital bone there are two condyles for connection with the first cervical vertebra, and between them - foramen magnum. On the sides of the occipital bone one can see a complex relief of the lower surface of the temporal bones with openings for the passage of nerves and blood vessels, an 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 front 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 the pituitary fossa contains the pituitary gland. In the posterior cranial fossa, bounded by the occipital and temporal bones, are the cerebellum and occipital lobes of the brain.