Human bones and their names. General structure of the human skeleton

In the human body, everything is interconnected and arranged very wisely. The skin and muscle cover, internal organs and skeleton, all this clearly interacts with each other, thanks to the efforts of nature. The following is a description of the human skeleton and its function.

general information

The frame of bones of different sizes and shapes, on which the human body is fixed, is called the skeleton. It serves as a support and provides reliable security to important internal organs. What the human skeleton looks like can be seen in the photo.

Described organ, connecting with muscle tissues, is the musculoskeletal system of Homo sapiens. Thanks to this, all individuals can move freely.

Finally developed bone tissue consists of 20% water and is the strongest in the body. Human bones include inorganic substances, due to which they have strength, and organic, which give flexibility. That is why the bones are strong and resilient.

human bone anatomy

Looking at the organ in more detail, it is clear that it consists of several layers:

• External. Forms bone tissue of high strength;
• Connective. The layer tightly covers the bones from the outside;
• Loose connective tissue. Here are complex weaves of blood vessels;
• cartilage tissue. It settled at the ends of the organ, due to it the bones have the opportunity to grow, but up to a certain age;
• Nerve endings. They, like wires, carry signals from the brain and vice versa.

Bone marrow is placed in the cavity of the bone tube, it is red and yellow.

Functions

Without exaggeration, we can say that the body will die if the skeleton stops performing its important functions:

• support. The solid bone-cartilaginous frame of the body is formed by bones, to which fascia, muscles and internal organs are attached.
• Protective. Of these, receptacles have been created for the maintenance and protection of the spinal cord (spine), the brain (cranial box) and for other equally important organs of human vital activity (rib frame).
• Motor. Here we observe the exploitation of bones by muscles, as levers, for the movement of the body with the help of tendons. They predetermine the coherence of joint movements.
• Cumulative. In the central cavities of long bones, fat accumulates - this is yellow bone marrow. The growth and strength of the skeleton depends on it.
• In metabolism bone tissue plays an important role, it can be safely called a pantry of phosphorus and calcium. It is responsible for the metabolism of additional minerals in the human body: sulfur, magnesium, sodium, potassium and copper. When there is a shortage of any of these substances, they are released into the blood and distributed throughout the body.
• hematopoietic. In hematopoiesis and bone formation, filled with blood vessels and nerves, the red bone marrow takes an active part. The skeleton contributes to the creation of blood and its renewal. The process of hematopoiesis takes place.

Organization of the skeleton

Into the skeletal structure includes several groups of bones. One contains the spine, cranium, chest and is the main group, which is a supporting structure and forms a frame.

The second, additional group, includes the bones that form the arms, legs and bones that provide a connection with the axial skeleton. Each group is described in more detail below.

Basic or axial skeleton

The skull is the bone base of the head.. It is half an ellipsoid in shape. Inside the cranium is the brain, here the sense organs have found their place. Serves as a solid support for the elements of the respiratory and digestive apparatus.

The thorax is the bone base of the chest. It resembles a compressed truncated cone. It is not only a support, but also a mobile device, participating in the work of the lungs. The internal organs are located in the chest.

Spine- an important part of the skeleton, it provides a stable vertical position of the body and contains the brain in its back, protecting it from damage.

Additional skeleton

The belt of the upper limbs - allows the upper limbs to join the axial skeleton. It consists of a pair of shoulder blades and a pair of clavicles.

upper limbs - unique working tool, which is indispensable. It consists of three sections: shoulder, forearm and hand.

Belt of the lower extremities - attaches the lower extremities to the axial frame, and is also a convenient receptacle and support for the digestive, reproductive and urinary systems.

Lower limbs - mainly perform supporting, motor and spring functions human body.

About the human skeleton with the name of the bones, as well as how many there are in total in the body and each department, is described below.

Departments of the skeleton

In an adult, the skeleton contains 206 bones. Usually its anatomy debuts with a skull. Separately, I would like to note the presence of the external skeleton - the dentition and nails. The human frame consists of many paired and unpaired organs, forming separate skeletal parts.

skull anatomy

The structure of the cranium also includes paired and unpaired bones. Some are spongy, while others are mixed. There are two main sections in the skull, they differ in their functions and development. Right there, in the temporal region, is the middle ear.

The brain department creates a cavity for part of the sense organs and the brain of the head. It has a vault and a base. There are 7 bones in the department:

• frontal;
• wedge-shaped;
• Parietal (2 pcs.);
• Temporal (2 pcs.);
• Trellised.

The facial section includes 15 bones. It contains most of the sense organs. This is where they start parts of the respiratory and digestive systems.

The middle ear contains a chain of three small bones that transmit sound vibrations from the eardrum to the labyrinth. There are 6 of them in the skull. 3 on the right and 3 on the left.

• Hammer (2 pcs.);
• Anvil (2 pcs.);
• The stirrup (2 pcs.) is the smallest bone measuring 2.5 mm.

Torso Anatomy

This includes the spine starting from the neck. The chest is attached to it. They are very related in terms of location and functions they perform. We will separately consider spinal column then chest.

vertebral column

The axial skeleton consists of 32–34 vertebrae. They are interconnected by cartilage, ligaments and joints. The spine is divided into 5 sections and in each section there are several vertebrae:

• Neck (7 pcs.) This includes epistrophy and atlas;
• Thoracic (12 pcs.);
• Lumbar (5 pieces);
• sacral (5 pcs.);
• Coccygeal (3-5 fused).

The vertebrae are separated by 23 intervertebral discs. This combination is called: partially movable joints.

Rib cage

This part of the human skeleton is formed from the sternum and 12 ribs, which are attached to 12 thoracic vertebrae. Flattened from front to back and expanded in the transverse direction, the chest forms a mobile and durable rib lattice. It protects the lungs, heart and major blood vessels from damage.

Sternum.

It has a flat shape and a spongy structure. It contains a rib cage in front.

Upper limb anatomy

With the help of the upper limbs, a person performs a lot of elementary and complex actions. Hands include many small parts and are divided into several departments, each of which conscientiously performs its work.

In the free part of the upper limb includes four sections:

• The belt of the upper limb includes: 2 shoulder blades and 2 collarbones.
• Shoulder bones (2 pcs.);
• Elbow (2 pcs.) And radial (2 pcs.);
• Brush. This complex part is arranged from 27 small fragments. Bones of the wrist (8 x 2), metacarpus (5 x 2) and phalanges of the fingers (14 x 2).

Hands are an exceptional apparatus for fine motor skills and precise movements. Human bones are 4 times stronger than concrete, so you can perform rough mechanical movements, the main thing is not to overdo it.

Anatomy of the lower extremities

The bones of the pelvic girdle form the skeleton of the lower extremities. The human legs are made up of many small parts and are divided into sections:

The leg skeleton is similar to the arm skeleton. Their structure is the same, but the difference can be seen in the details and size. The entire weight of the human body lies on the legs when moving. Therefore, they are stronger and stronger than the hands.

Bone Shapes

In the human body, the bones are not only different sizes, but also shapes. There are 4 types of bone shapes:

• Broad and flat (like a skull);
• Tubular or long (in limbs);
• Having a composite shape, asymmetrical (pelvic and vertebrae);
• Short (bones of the wrist or foot).

Having considered the structure of the human skeleton, we can conclude that it is an important structural component of the human body. It performs the functions due to which the body carries out the normal process of its life.

Skeleton(from the Greek skeleton - dried) of a person is a collection of bones connected in a certain way to each other. In an adult, the skeleton consists of approximately 205 bones. Three sections are distinguished in the skeleton (Fig. 12): the skeleton of the body, the skeleton of the skull and the skeleton of the limbs (Table 2).

Rice. 12. Human skeleton (front view):

1 - cerebral skull, 2 - facial skull, 3 - bones of the girdle of the upper limb 4 - humerus, 5 - bones of the forearm, 6 - bones of the hand, 7 - chest 8 - spinal column, 9 - bones of the girdle of the lower extremities, 10 - femur , 11 - leg bones, 12 - foot bones

The skeleton of the trunk consists of the vertebrae that form the spine and the bones of the chest. Each segment of the skeleton of the human body is formed by a vertebra, and in the thoracic region also by a pair of ribs and a portion of the sternum.

The skeleton of the head - the skull, protects the brain, sensory organs and serves as a support for the initial sections of the digestive and respiratory organs. The skull is conditionally divided into two sections - cerebral and facial.

The skeleton of the upper and lower extremities is divided into the skeleton of the free limb and the skeleton of the girdle. The skeleton of the girdle of the upper limbs (shoulder girdle) consists of two paired bones - the scapula and the collarbone, and the skeleton of the free upper limb - of three sections: the humerus, the bones of the forearm and the bones of the hand.

The skeleton of the girdle of the lower extremities (pelvic girdle) consists of a paired pelvic bone, and the skeleton of the free lower limb is divided into three sections: the femur, the bones of the lower leg and the bones of the foot. Each bone is an independent organ that performs a specific function.

The bones of the skeleton differ in shape and structure. Distinguish tubular, sponge, flat, mixed and air bones(Fig. 13).

Rice. 13. Types of bones:

1 - long (tubular) bone, 2 - flat bone, 3 – spongy (short) bones, 4 – mixed bone

Tubular bones are divided into long (humerus, femur, bones of the forearm and lower leg) and short (bones of the metatarsus and tarsus, phalanges of the fingers). Bones, with the exception of the articular surfaces, are covered with a connective tissue sheath - periosteum, which performs bone-forming and protective functions. The periosteum is firmly fused to the bone with the help of connective tissue fibers that penetrate deep into the bone. The outer layer of the periosteum is coarse-fibred, consisting of intricately intertwined fibers and connective tissue cells. In this layer there are many blood and lymphatic vessels, nerve fibers that ensure the vital activity of the bone. The inner layer of the periosteum is thin, contains cells from which osteoblasts are formed - young bone cells. Due to the bone-forming function of the periosteum, the bone grows in thickness and fuses with fractures.

Inside the bones are medullary cavity(in tubular bones) and spongy cells, in which the bone marrow is located. In a newborn child and in childhood, the bone marrow cavities are filled with red bone marrow, which performs blood-forming and protective functions. From the stem cells of the red bone marrow, blood cells (erythrocytes, leukocytes) and cells of the immune system (lymphocytes) are formed. In an adult, red bone marrow is preserved only in the cells of the cancellous bone. Other bony cavities contain obese yellow bone marrow that has lost its function.

From the side of the medullary cavity and cells, the bone is covered with a thin connective tissue plate - endosteum, also producing bone tissue.

The bones of the skeleton and the whole skeleton perform supporting, motor protective functions. Bones are also a depot for mineral deposits - phosphorus, calcium, iron, copper and other trace elements.

Bone strength It is ensured by the presence of organic and inorganic substances in them, as well as by the structure of bone tissue. In terms of hardness and elasticity, bones can be compared with bronze and cast iron. The compact and spongy substance of bones is built from bone tissue. Compact (dense) bone substance forms the outer layer of each bone. sponge substance, formed by bone crossbars (beams), is located under a compact substance. In tubular bones in the area of ​​​​their body (diaphysis), the compact bone substance is thick (up to 1 cm). At the ends of tubular bones in flat and other bones, this layer is thin. The compact bone substance is permeated with a system of bone canals, in which blood vessels and nerve fibers are located (Fig. 14).

Rice. 14. Scheme of the structure of the tubular bone:

1 - periosteum, 2 - compact bone substance, 3 - layer of outer surrounding plates, 4 - osteons, 5 - layer of inner surrounding plates, 6 - medullary cavity, 7 - bone crossbars of cancellous bone substance.

Each bone channel (osteon channel) is surrounded by concentric plates in the form of 4-20 thin tubes inserted one into the other. The system of such tubules together with the tubule is called osteon, or haversian system(Fig. 15). The spaces between the osteons are occupied by intermediate, or insertion, plates, which, when the bone is restructured due to changing physical load, serve as material for the formation of new osteons. The surface layer of compact bone substance is represented by the outer surrounding plates, which are the product of the bone-forming function of the periosteum.

Rice. 15. The structure of the osteon in the section: 1 - osteon plates, 2 - bone cells (osteocytes), 3 - central canal (osteo canal)

The inner layer of the bone, bordering the medullary cavity, is formed by the inner surrounding plates and is covered with fibrous connective tissue - the endosteum.

spongy bone, located under the compact, is located at the ends of the tubular bones - the epiphyses, in the bodies of spongy, mixed bones, in flat and air bones. Spongy bone substance consists of bone crossbars that intersect each other in different directions. Their distribution corresponds to the direction of the main lines of compression (pressure) and tension acting on the bone (Fig. 16).

Rice. 16. Scheme of the location of the bone crossbars in the cancellous bone (cutting the upper end of the femur): 1 - lines of compression (pressure), 2 - lines of tension

Such an arrangement of the bone crossbars at an angle to each other ensures a uniform distribution of pressure and force of the muscles on the bones of the skeleton.

Bone is highly plastic. Depending on the magnitude of the load on the bones, the number of osteons increases or decreases, their location in the compact substance changes. With constant muscle load, sports, physical labor, the number of osteons and their size increase, the layer of compact bone substance in tubular and other bones thickens, and the medullary cavities narrow. The bone crossbars (beams) of the spongy substance also thicken, acquire a more complex structure (branch). The bones become thicker and stronger. With a decrease in physical (muscular) load, with a sedentary lifestyle, prolonged bed rest during illness, the bones become thinner, weaker.

Bone strength is also provided by organic and inorganic substances. Organic substances give bones flexibility and elasticity.

Inorganic substances (calcium phosphate, calcium carbonate and other salts) give bones hardness. In living bone, organic matter accounts for about 60% of its mass, the rest belongs to inorganic compounds.

The effect of organic and inorganic substances on the strength properties of bones can be verified experimentally. After the removal of organic matter by roasting the bone in a fire, it becomes brittle. Removal of inorganic substances (salts) from the bone by keeping the bone in acid makes the bone soft and flexible. The combination of the hardness of inorganic compounds with the elasticity of organic compounds provides bone strength.

Similar information.

The structure of the human skeleton and its age features

The human skeleton consists of the following sections: the skeleton of the head, the skeleton of the body, the skeleton of the upper limbs and the skeleton of the lower limbs.

It is subdivided into the bones of the cerebral and visceral skull. The first includes: occipital, frontal, wedge-shaped, ethmoid, parietal and temporal. The visceral skull consists of the mandibular, maxillary, zygomatic, palatine, nasal, and lacrimal bones. Starting from the age of 13, the growth of the visceral part of the skull prevails over the brain.

Torso skeleton consists of the vertebral column and chest. The first consists of 33-34 vertebrae, of which 7 are cervical, 12 thoracic, 5 lumbar, 5 sacral and 3-5 coccygeal. Each vertebra consists of a body and an arch, from which one spinous process and two lateral ones depart. The vertebrae form the spinal canal. The chest is formed by the sternum, ribs and thoracic vertebrae. The sternum consists of a handle, body and xiphoid process. The ribs, in the amount of 12 pairs, are divided into 7 pairs of true ribs (1-7), connected directly to the sternum, and 5 pairs (8-12) of false ones, of which 3 pairs (8-10) are attached with their cartilage to the cartilage of the seventh rib , and two pairs (11 and 12) are not connected with the sternum. Cartilage 7-10 pairs form the costal arch. The spinal column of a newborn is almost straight. When the child begins to hold his head (3 months), the first cervical lordosis (anterior bend) appears. By the 6th month of life, when the child begins to sit, there is a thoracic kyphosis (posterior bend). When the child begins to stand and walk, lumbar lordosis appears and sacral kyphosis becomes stronger. Physiological curves are fixed in children in the cervical and thoracic spine at 6-7 years old, and in the lumbar - at 12 years old. The chest in children is squeezed from the sides. With age, it expands and by the age of 12 takes the form of an adult.

The skeleton of the upper limbs and their girdle. The skeleton of the upper extremities consists of the humerus (anatomical shoulder), the bones of the forearm (radius and ulna), the skeleton of the hand (carpal bones, metacarpal bones and phalanges of the fingers). The wrist skeleton is made up of 8 bones. The skeleton of the metacarpus consists of 5 bones. The skeleton of the girdle of the upper limbs (shoulder girdle) consists of the clavicles and shoulder blades.

The skeleton of the lower limbs and their girdle. The skeleton of the lower limb consists of the femur, the bones of the lower leg (greater and fibular), the skeleton of the foot, which includes the bones of the tarsus (7 bones), the metatarsal bones (5 bones) and the phalanx of the fingers. The skeleton of the girdle of the lower extremities (pelvic girdle) is represented by the pelvic bone, which up to 15 years of age consists of 3 bones: the ilium, ischium and pubis. The two parts of the pubic bone are connected by the so-called pubic symphysis - a cartilaginous joint with a special structure.

Rice. 24. Head skeleton.

The connection of the bones of the human skeleton

The bones of the skull are fixedly connected, with the exception of the lower jaw, which forms the temporomandibular joint with the temporal bone. In a newborn child, between the bones of the skull there are 4 fontanelles formed by connective tissue. The frontal (anterior) fontanel is located between the frontal and parietal bones. Disappears in 1.5 - 2 years. The occipital (posterior) fontanel, located between the occipital and parietal bones, disappears up to 3 months of a child's life. Lateral fontanelles (mastoid and wedge-shaped) are paired. Disappear in the first days of a child's life (see Fig. 71).

The connection of the spinal column with the skull is carried out by the atlantooccipital joint. The vertebral bodies are connected by intervertebral discs, and the articular processes are connected by intervertebral joints. The ribs are connected to the vertebrae by the costovertebral joints. Costal cartilages 2-7 pairs of ribs are connected to the sternum - sternocostal joints.

The skeleton of the shoulder girdle is connected with the clavicle to the sternum, forming the sternoclavicular joint, and with the help of the scapula with the humerus, forming the acromioclavicular joint. The elbow joint consists of the pre-elbow, pre-radius and upper radio-ulnar joints. Between the forearm and hand are the wrist and lower radioulnar joints. Between the upper and lower rows of bones of the wrist is the intercarpal joint. The carpometacarpal joints are located between the bones of the wrist and metacarpus, and the metacarpophalangeal joints are between the metacarpal bones and phalanges of the fingers. Interphalangeal joints are located between the bones of the fingers.

The skeleton of the pelvic girdle is articulated with the sacrum by the sacroiliac joint, and with the limb by the hip joint. The knee joint is located between the femur and tibia. The small and large tibia are connected to each other by the upper and lower tibial joints. These bones with the tarsus form the ankle joint. In the tarsus, the subtalar and transverse joints are distinguished. Between the tarsus and metatarsus are the tarsal-metatarsal joints. The metatarsophalangeal joints are located between the phalanges of the fingers and the metatarsal bones, and the interphalangeal joints are between the phalanges of the fingers.

"

Rice. 71. Skull of a Newborn.

1 - anterior fontanel; 2 - parietal tubercle; 3 - posterior fontanel; 4 - mastoid fontanel; 5 - wedge-shaped fontanel; 6 - frontal tubercle.

In the article you will get acquainted with the structure of the human skeleton and learn the names of the bones.

The human skeleton - a structure with the name of the bones: diagram, photo in front, side, back, description

Everyone knows that the skeleton is the human skeletal system. The skeleton is a collection of passive and movable bones. Without a skeleton, the human body simply cannot hold on: all its internal organs and soft tissues, muscles.

INTERESTING: In the human adult formed body, a total of about 200 bones are contained. But in the body of a newborn, the number of bones is much larger - there are 270 of them! This is very simple to explain - after a while, small bones form into large ones.

All bones in the skeleton are connected by ligaments and joints (types of connective tissue). Surprisingly, at different stages of life, a person experiences many transformations of his skeleton. The most amazing of them is the transformation of the cartilaginous skeleton into a bone one.

The main parts of the human skeleton, the number, weight of bones

The skeleton is conditionally divided into two groups:

• Ostevoi
• Additional

Skeletal skeleton:

• Scull -"bone" of the head. It is in this bone that one of the most important internal organs of the human body is located - the brain.
• "receptacle" of the most important internal organs, their "body" and protection. There are 12 vertebrae and the same number of pairs of ribs in a cell.
• Spine - it is the axis of the body in which the spinal cord runs.

Additional skeleton:

• Upper limb belt(shoulder blades and collarbones)
• upper limbs
• Belt of the lower extremities
• lower limbs

What tissue is the basis of the bones of the skeleton, what substance gives the human skeleton strength, what is the composition of the bones?

The skeleton is the hardest, strongest and strongest foundation of the body. It has the most important functions, without which human life would be simply impossible. It provides support, the ability to move, protects the internal organs.

The skeleton is made of bones, and the bone is made of bone tissue. What is bone tissue? This is a type of connective tissue. Few people know that inside the bone there are nerves and blood vessels. Bone tissue cells have a large number of processes surrounded by special "channels" with liquid. It is through this fluid that the “breathing” of cells occurs.

This fluid is called "intercellular" and it consists of organic substances (protein) and inorganic (calcium and potassium salts). This composition allows the bones to be flexible and elastic at the same time.

INTERESTING: Surprisingly, children's bones differ in that they are more flexible, and the bones of adults are much stronger.

Anatomical skeleton of the chest, human pelvis: diagram, description

Examine the detailed photo of the chest to see each bone and its name.

Human chest:

• Two sides
• Backside
• Front side

The chest is made up of:

• Thoracic vertebrae
• Ribs
• Breast bone (sternum)
• Top and middle handle
• xiphoid process

Features of the structure of the chest:

• The first edge is horizontal
• The ribs are connected to the sternum by cartilage
• The most important internal organs "hide" in the chest

INTERESTING: The chest helps a person breathe by helping to reduce or increase the volume of air in the lungs with movements. The chest of men is larger than that of women, but the female is wider.

Anatomical skeleton of the hand, human hand: diagram, description

The human hand is made up of many bones.

The hand is divided into three parts:

• Shoulder
• Forearm
• Brush

It's important to know:

• The bone base of the shoulder is the humerus
• Bone base of the forearm - ulna and radius
• The hand is made up of 27 individual bones.
• Metacarpus contains 5 bones
• The skeleton of the fingers consists of 14 phalanges

Anatomical skeleton of the human shoulder and forearm: diagram, description

Here you can see in detail the bones of the shoulder and forearm with names.

Anatomical skeleton of the neck, human skull: diagram, description

The pictures show in detail all the important human bones.

Anatomical skeleton of the leg, human foot: diagram, description

The human foot also has many bones.

What bones in the human skeleton are connected movably with the help of a joint and motionless?

It is important to know which bones in the human skeleton are movably connected by joints or motionless.

What is the role of the human skeleton, what provides mobility, what is the mechanical function of the bones of the skeleton?

Functions:

• Musculoskeletal (body support and fastening of soft tissues, organs, body mobility).
• Locomotion (transportation of the body)
• Spring (softening the shock point)
• Protective (protection of internal organs from injury)

What are the structural features of the human skeleton associated with bipedalism?

The human skeleton can be characterized by the fact that it has an upright position. The spine is held straight, but has curves. While walking, he is able to "spring", softening all shocks. Due to the fact that a person walks straight, his chest is expanded.

The hand is an organ of labor, the thumb is removed and developed so that it is convenient to grab and hold an object. The belt has the form of a bowl and is a support for the pelvic organs. The lower limbs are stronger than the arms and confidently hold the "heavy" body.

Until what age does the human skeleton grow?

The human skeleton goes through several active stages of formation:

• First "early": from 0 to 7 years
• Second "teenage": from 11 to 17 years old
• The third "final": in women under 25, in men up to 30.

What bones are tubular in the human skeleton?

Long tubular:

• femoral
• tibial
• fibula

Short tubular:

• Metatarsals
• Phalangeal
• Metacarpal

What is the longest, most massive, strongest and smallest bone in the human skeleton?

• The longest bone femoral
• The most usedbig - tibial
• The strongest - femoral
• The smallest -"anvil" or "stirrup" (in the ear)

Video: "The structure of the skeleton"

The human skeleton is divided into torso skeleton, head skeleton, limb skeleton and their belts.

Torso skeleton

Torso skeleton includes the spine and thorax. formed by 33-34 vertebrae located one above the other. Between the vertebral bodies are layers of cartilage, giving the spine flexibility and elasticity.

There are five sections of the spine: cervical, consisting of 7 vertebrae, chest- out of 12, lumbar- out of 5, sacral- from 5 and coccygeal(caudal) - from 4–5 fused vertebrae. Each vertebra is made up of body, arcs and processes. There is a hole between the body and the arc.

The vertebral foramina together form spinal canal, in which lies spinal cord. The first two cervical vertebrae provide rotation of the head. The most massive vertebrae are located in the lumbar region, which bears the greatest weight of the body. The sacral vertebrae fuse into a massive bone - sacrum. The coccygeal bones are underdeveloped and represent a rudiment of the tail of human animal ancestors.

Head skeleton

Head skeleton- the skull is made up of paired and unpaired bones, most of them are flat, connected to each other motionless - seams. In the skull are distinguished cerebral and facial departments. The brain section consists of eight bones: four of them are unpaired - occipital, wedge-shaped, lattice, frontal and two pairs parietal and temporal.

Occipital bone forms the back wall of the skull and its base, has a large occipital foramen, through which the spinal cord is connected to the brain. In the center of the base of the skull is placed sphenoid bone. frontal bone lies in front of the parietal and is part of the skull roof. It is characterized by frontal tubercles and superciliary arches.

Ethmoid bone It is built of thin bone plates, between which there are air cavities. temporal bones occupy the anterolateral sides of the brain skull. Parietal- form the middle of the skull roof. The facial section of the skull consists of 6 paired and 3 unpaired bones. Of these, the lower part - the only movable bone of the skull - is articulated by two heads of the articular process with the mandibular fossa of the temporal bone. The upper and lower jaws contain 16 cells each, in which the roots of the teeth are placed.

In addition to the jaw bones, in the facial region there are nasal bones, coulter- an unpaired bone involved in the formation of the nasal septum, lacrimal bones, zygomatic and palatine.

Upper limb skeleton

Upper limb skeleton consists of a shoulder girdle and free limbs - hands. Shoulder girdle formed by two paired bones: spatula and clavicle. Two triangular shoulder blades are located on the back of the chest and articulate with the humerus and sternum.

The skeleton of the upper limb is formed by the bones: brachial connected to the blade forearms(radial and ulnar) and brushes. The hand skeleton is formed small bones of the wrist, long bones of the pastern and finger bones. The bones of the forearm, together with the shoulder, make up a complex elbow joint, and with the bones of the wrist, the wrist joint.

The hand includes 8 small bones of the wrist arranged in two rows, five bones of the metacarpus forming the palm and fourteen phalanges of the fingers, of which the thumb has two phalanges, and the rest have three.

Skeleton of the lower extremities

Skeleton of the lower extremities is divided into the skeleton of the pelvic girdle and the skeleton of free limbs - legs.

Pelvic girdle consists of two massive flat pelvic bones, firmly fused to the sacrum at the back, and almost rigidly connected to each other in front in a false articulation. They have round depressions where the heads of the femurs enter.

The skeleton of the lower limb consists of bones: femoral, shins(tibia tibia and tibia) and feet. The knee joint - the junction of the thigh and lower leg - is protected in front by a small flat patella. The moaning skeleton is formed by the short bones of the tarsus, the long bones of the metatarsus, and the phalanges of the fingers. In connection with the upright posture, the human foot has acquired an arched shape, which gives it the properties of a spring and provides a springy gait.

Features of the human skeleton associated with upright posture and labor activity - 4 smooth curves of the spine, a wide chest, massive bones of the lower extremities, wide pelvic bones, arched foot, the predominance of the cerebral part of the skull over the facial.