Examples of flat human bones. Bones are categorized according to their shape and structure.

06.11.2019 -

Everyone needs to know the human skeleton with the name of the bones. This is important not only for doctors, but also for ordinary people, because information about his skeleton and muscles will help strengthen him, feel healthy, and at some point they can help out in emergency situations.

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Types of bones in the adult body

The skeleton and muscles together make up the human locomotor system. The human skeleton is a complex of bones different types and cartilage, interconnected with the help of continuous connections, synarthroses, symphyses. Bones are divided into:

tubular, forming the upper (shoulder, forearm) and lower (thigh, lower leg) limbs;
spongy, foot (in particular, tarsus) and human hand (wrists);
mixed - vertebrae, sacrum;
flat, this includes the pelvic and cranial bones.

Important! Bone tissue, despite its increased strength, is able to grow and recover. Metabolic processes take place in it, and blood is even formed in the red bone marrow. With age, bone tissue is rebuilt, it becomes able to adapt to various loads.

Types of bones

How many bones are in the human body?

The structure of the human skeleton undergoes many changes throughout life. On the initial stage development, the fetus consists of fragile cartilage tissue, which over time is gradually replaced by bone. A newborn baby has over 270 small bones. With age, some of them can grow together, for example, cranial and pelvic, as well as some vertebrae.

It is very difficult to say exactly how many bones in the body of an adult. Sometimes people have extra ribs or bones in the foot. There may be growths on the fingers, a slightly smaller or larger number of vertebrae in any of the spine. The structure of the human skeleton is purely individual. On average in an adult have from 200 to 208 bones.

Functions of the human skeleton

Each department performs its highly specialized tasks, but the human skeleton as a whole has several common functions:

Support. The axial skeleton is a support for all soft tissues of the body and a system of levers for the muscles.
Motor. Movable joints between bones allow a person to make millions of precise movements with the help of muscles, tendons, ligaments.
Protective. The axial skeleton protects the brain and internal organs from injury, acts as a shock absorber during impacts.
Metabolic. The composition of bone tissue includes a large amount of phosphorus and iron involved in the exchange of minerals.
Hematopoietic. red brain tubular bones is the place where hematopoiesis takes place - the formation of erythrocytes (red blood cells) and leukocytes (cells of the immune system).

If some skeletal functions are impaired, diseases may occur. varying degrees gravity.

Functions of the human skeleton

Departments of the skeleton

The human skeleton is divided into two large sections: axial (central) and additional (or limb skeleton). Each department performs its own tasks. The axial skeleton protects the abdominal organs from damage. The skeleton of the upper limb connects the arm to the torso. Due to the increased mobility of the bones of the hand, it helps to perform many precise finger movements. Skeleton Functions lower extremities consist in tying the legs to the body, moving the body, depreciation when walking.

Axial skeleton. This department forms the basis of the body. It includes: the skeleton of the head and torso.

Head skeleton. The cranial bones are flat, immovably connected (with the exception of the movable mandible). They protect the brain and sense organs (hearing, sight and smell) from concussions. The skull is divided into the facial (visceral), cerebral and middle ear sections.

Torso skeleton. The bones of the chest. In appearance, this subsection resembles a compressed truncated cone or pyramid. The chest includes paired ribs (out of 12, only 7 are articulated with the sternum), the vertebrae of the thoracic spine and the sternum - an unpaired sternum.

Depending on the connection of the ribs with the sternum, true (upper 7 pairs), false (next 3 pairs), floating (last 2 pairs) are distinguished. The sternum itself is considered the central bone included in the axial skeleton.

The body is isolated in it, upper part- the handle, and the lower part - xiphoid process. The bones of the chest are connection of increased strength with the vertebrae. Each vertebra has a special articular fossa designed for attachment to the ribs. This method of articulation is necessary to perform the main function of the skeleton of the body - the protection of human life support organs:, lungs, parts of the digestive system.

Important! The bones of the chest are subject to external influences, prone to modification. Physical activity and proper seating at the table contribute to proper development chest. A sedentary lifestyle and stoop lead to tightness of the chest organs and scoliosis. An improperly developed skeleton threatens serious problems with health.

Spine. The department is central axis and main support Total human skeleton. The spinal column is formed from 32-34 individual vertebrae that protect the spinal canal with nerves. The first 7 vertebrae are called cervical, the next 12 are thoracic, then come the lumbar (5), 5 fused, forming the sacrum, and the last 2-5, constituting the coccyx.

The spine supports the back and torso, ensures the motor activity of the whole organism and the connection of the lower body with the brain due to the spinal nerves. The vertebrae are connected to each other semi-mobile (in addition to the sacral). This connection is made through intervertebral discs. These cartilaginous formations soften shocks and tremors during any movement of a person and provide flexibility to the spine.

limb skeleton

Skeleton of the upper limb. Skeleton of the upper limb represented by the shoulder girdle and the skeleton of the free limb. The shoulder girdle connects the arm to the body and includes two paired bones:

The clavicle, which has an S-shaped bend. At one end it is attached to the sternum, and at the other it is connected to the scapula.
Shoulder blade. In appearance, it is a triangle adjacent to the back of the body.

The skeleton of the free limb (hand) is more mobile, since the bones in it are connected large joints(shoulder, wrist, elbow). Skeleton represented by three subdivisions:

Shoulder, which consists of one long tubular bone - the humerus. One of its ends (epiphyses) is attached to the scapula, and the other, passing into the condyle, to the forearms.
Forearm: (two bones) the ulna, located on the same line with the little finger and the radius - in line with the first finger. Both bones on the lower epiphyses form a wrist joint with the carpal bones.
A brush that includes three parts: the bones of the wrist, metacarpus and finger phalanges. The wrist is represented by two rows of four spongy bones in everyone. The first row (pisiform, trihedral, lunate, navicular) serves to attach to the forearm. In the second row are the hamate, trapezium, capitate and trapezoid bones facing the palm. The metacarpus consists of five tubular bones, with their proximal part they are motionlessly connected to the wrist. Finger bones. Each finger consists of three phalanges connected to each other, in addition to the thumb, which is opposed to the rest, and has only two phalanges.

Skeleton of the lower limb. The skeleton of the leg, as well as the hand, consists of a limb belt and its free part.

limb skeleton

The belt of the lower extremities is formed by paired pelvic bones. They grow together from paired pubic, iliac and ischial bones. This happens by the age of 15-17, when the cartilaginous connection is replaced by a fixed bone one. Such strong articulation is necessary for the maintenance of the organs. Three bones to the left and right of the axis of the body form along the acetabulum, which is necessary for the articulation of the pelvis with the head of the femur.

The bones of the free lower limb are divided into:

Femoral. The proximal (upper) epiphysis connects to the pelvis, and the distal (lower) to the tibia.
The patella (or patella) covers, formed at the junction of the femur and tibia.
The lower leg is represented by the tibia, located closer to the pelvis, and the fibula.
Foot bones. The tarsus is represented by seven bones that make up 2 rows. One of the largest and well developed is the calcaneus. The metatarsus is the middle part of the foot, the number of bones included in it is equal to the number of fingers. They are connected to the phalanges by means of joints. Fingers. Each finger consists of 3 phalanges, except for the first, which has two.

Important! During life, the foot is subject to modifications, calluses and growths can form on it, and there is a risk of developing flat feet. Often this is due to the wrong choice of shoes.

Sex differences

The structure of a woman and a man has no major differences. Only separate parts of some bones or their sizes are subject to changes. Among the most obvious, a narrower chest and a wide pelvis in a woman are distinguished, which is associated with labor activity. The bones of men, as a rule, are longer, more powerful than women's, and have more traces of muscle attachment. Distinguishing a female skull from a male is much more difficult. The skull of men is slightly thicker than the female, it has a more pronounced contour of the superciliary arches and the occipital protuberance.

The human skeleton consists of the following parts: bones of free limbs - upper (bones of the hand and forearm, shoulder) and lower (bones of the foot and lower leg, thigh); bones of the limb belts - upper (collarbone and shoulder blade) and lower (pelvic); skeleton of the head (bones of the face and skull); bones of the body (sternum, ribs, vertebrae).

The adult human skeleton consists of more than 200 bones. The bones of the skeleton vary in shape, as mixed, flat, short and long. But such a division of bones (in form) is formal and one-sided. For example, the parietal bone belongs to the group flat bones, while in fact it is a typical integumentary bone, ossifying endesmally. In addition, pathological processes in the bones and phalanges of the wrist are completely different, despite the fact that they belong to short bones. Based on this, it was proposed to distinguish bones according to three main principles: form (structure), functions and development.

The classification of bones is as follows:

Mixed bones.

Flat bones - the bones of the belts and the bones of the skull.

Spongy bones - sesamoid, short, long.

Tubular bones - short and long.

Tubular bones are built from a compact and spongy substance, which form a tube with a bone marrow cavity. Tubular bones perform such functions as movement, protection and support. Long tubular bones include the bones of the lower leg, thigh, bones of the forearm and shoulder. They are long and persistent levers of movement, in both epiphyses they have foci of ossification. Short tubular bones include phalanges, metatarsus, and metacarpal bones. Short tubular bones are short levers of movement.

Of a spongy substance that is covered thin layer compact, predominantly spongy bones. There are short (tarsus, wrist bones, vertebrae) and long (sternum and ribs) spongy bones. Sesamoid bones are spongy bones. They look like sesame seeds, which is why they are given this name. Their main function is an auxiliary device for the work of muscles. They have endochondral development in the thickness of the tendons. Sesamoid bones are located near the joints, in whose formation they participate, and also contribute to movement in them. They are not directly connected to the bones of the skeleton.

The flat bones are flat bones of the skull(parietal and frontal), the main function of which is protective. They consist of a compact substance in the form of two thin plates. Between them there is a spongy substance - dirloe, which contains channels for veins. Such bones are integumentary, their development is based on connective tissue.

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Human skeleton: functions, departments

The skeleton is a collection of bones, cartilage belonging to them and ligaments connecting the bones.

There are more than 200 bones in the human body. The weight of the skeleton is 7-10 kg, which is 1/8 of the weight of a person.

The human skeleton has the following departments:

head skeleton(scull), torso skeleton- axial skeleton;
belt upper limbs , lower limb belt- additional skeleton.

Human skeleton front

Skeleton Functions:

Mechanical functions:

support and fastening of muscles (the skeleton supports all other organs, gives the body a certain shape and position in space);
protection - the formation of cavities (the cranium protects the brain, the chest protects the heart and lungs, and the pelvis - bladder, rectum and other organs);
movement - a movable connection of bones (the skeleton, together with the muscles, makes up the motor apparatus, the bones in this apparatus play a passive role - they are levers that move as a result of muscle contraction).

biological functions:

mineral metabolism;
hematopoiesis;
deposition of blood.

Classification of bones, features of their structure. Bone as an organ

Bone- structural and functional unit of the skeleton and an independent organ. Each bone occupies an exact position in the body, has a certain shape and structure, and performs its own function. All types of tissues are involved in bone formation. Of course, the main place is occupied by bone tissue. Cartilage covers only the articular surfaces of the bone, the outside of the bone is covered with periosteum, inside it is located Bone marrow. Bone contains adipose tissue, blood and lymphatic vessels, and nerves. Bone tissue has high mechanical properties, its strength can be compared with the strength of metal. The relative density of bone tissue is about 2.0. Living bone contains 50% water, 12.5% protein organic matter (ossein and osseomucoid), 21.8% inorganic minerals (mainly calcium phosphate), and 15.7% fat.

In dried bone, 2/3 are inorganic substances, on which the hardness of the bone depends, and 1/3 are organic substances, which determine its elasticity. The content of mineral (inorganic) substances in the bone gradually increases with age, as a result of which the bones of the elderly and old people become more fragile. For this reason, even minor injuries in the elderly are accompanied by bone fractures. The flexibility and elasticity of bones in children depend on the relatively high content of organic substances in them.

Osteoporosis- a disease associated with damage (thinning) of bone tissue, leading to fractures and bone deformities. The reason is not the absorption of calcium.

The structural functional unit of the bone is osteon. Usually osteon consists of 5-20 bone plates. The diameter of the osteon is 0.3–0.4 mm.

If the bone plates are tightly adjacent to each other, then a dense (compact) bone substance is obtained. If the bone crossbars are located loosely, then a spongy bone substance is formed, in which the red bone marrow is located.

Outside, the bone is covered with periosteum. It contains blood vessels and nerves.

Due to the periosteum, the bone grows in thickness. Due to the epiphyses, the bone grows in length.

Inside the bone is a cavity filled with yellow marrow.

The internal structure of the bone

Bone classification in the form:

tubular bones- have a general structural plan, they distinguish between the body (diaphysis) and two ends (epiphyses); cylindrical or trihedral shape; length prevails over width; outside the tubular bone is covered with a connective tissue layer (periosteum):

long (femoral, shoulder);
short (phalanges of fingers).

spongy bones- formed mainly by spongy tissue, surrounded by a thin layer of solid matter; combine strength and compactness with limited mobility; the width of spongy bones is approximately equal to their length:

long (sternum);
short (vertebrae, sacrum)
sesamoid bones - located in the thickness of the tendons and usually lie on the surface of other bones (patella).

flat bones- formed by two well-developed compact outer plates, between which there is a spongy substance:

skull bones (skull roof);
flat (pelvic bone, shoulder blades, bones of the belts of the upper and lower extremities).

mixed dice- have a complex shape and consist of parts that are different in function, form and origin; due to complex structure mixed bones cannot be attributed to other types of bones: tubular, spongy, flat (thoracic vertebra, has a body, an arc and processes; the bones of the base of the skull consist of a body and scales).

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Lecture: Classification of bones according to shape and internal structure. Classification of bones.

In the skeleton, the following parts are distinguished: the skeleton of the body (vertebrae, ribs, sternum), the skeleton of the head (bones of the skull and face), the bones of the limb belts - the upper (scapula, collarbone) and lower (pelvic) and the bones of the free limbs - the upper (shoulder, bones forearms and hands) and lower (femur, bones of the lower leg and foot).

The number of individual bones that make up the skeleton of an adult is more than 200, of which 36-40 are located along the midline of the body and are unpaired, the rest are paired bones.
According to the external shape, the bones are long, short, flat and mixed.

However, such a division established back in the time of Galen according to only one feature (external form) turns out to be one-sided and serves as an example of the formalism of the old descriptive anatomy, as a result of which bones that are completely heterogeneous in structure, function and origin fall into one group.

So, the group of flat bones includes parietal bone, which is a typical integumentary bone, ossifying endesmally, and the scapula, which serves for support and movement, ossifies on the basis of cartilage and is built from ordinary spongy substance.
Pathological processes also proceed quite differently in the phalanges and bones of the wrist, although both of them belong to short bones, or in the thigh and rib, enrolled in one group of long bones.

Therefore, it is more correct to distinguish bones on the basis of 3 principles on which any anatomical classification should be built: forms (structures), functions and development.
From this point of view, the following classification of bones(M. G. Prives):
I. Tubular bones. They are built from a spongy and compact substance that forms a tube with a bone marrow cavity; perform all 3 functions of the skeleton (support, protection and movement).

Of these, long tubular bones (shoulder and bones of the forearm, femur and bones of the lower leg) are resistant and long levers of movement and, in addition to the diaphysis, have endochondral foci of ossification in both epiphyses (biepiphyseal bones); short tubular bones (carpal bones, metatarsus, phalanges) represent short levers of movement; of the epiphyses, the endochondral focus of ossification is present in only one (true) epiphysis (monoepiphyseal bones).
P. Spongy bones. They are built mainly of spongy substance, covered with a thin layer of compact.

Among them, long spongy bones (ribs and sternum) and short ones (vertebrae, carpal bones, tarsals) are distinguished. Spongy bones include sesamoid bones, that is, sesame plants similar to sesame grains, hence their name (patella, pisiform bone, sesamoid bones of the fingers and toes); their function is auxiliary devices for the work of muscles; development - endochondral in the thickness of the tendons. Sesamoid bones are located near the joints, participating in their formation and facilitating movements in them, but they are not directly connected with the bones of the skeleton.
III.

Flat bones:
a) flat bones of the skull (frontal and parietal) perform mainly a protective function. They are built from 2 thin plates of a compact substance, between which there is a diploe, diploe, a spongy substance containing channels for veins. These bones develop on the basis of connective tissue (integumentary bones);
b) flat bones of the belts (scapula, pelvic bones) perform the functions of support and protection, built mainly of spongy substance; develop on the basis of cartilage tissue.

Mixed bones (bones of the base of the skull). These include bones that merge from several parts that have different functions, structure and development. The clavicle, which develops partly endosmally, partly endochondral, can also be attributed to mixed bones.

7) the structure of the bone substance.
By microscopic structure bone substance is a special type of connective tissue, bone tissue, characteristics which: hard, fibrous impregnated with mineral salts intercellular substance and stellate, equipped with numerous processes, cells.

The basis of the bone is made up of collagen fibers with their soldering substance, which are impregnated with mineral salts and are formed into plates consisting of layers of longitudinal and transverse fibers; in addition, elastic fibers are also found in the bone substance.

These plates in the dense bone substance are partly located in concentric layers around the long branching channels passing in the bone substance, partly lie between these systems, partly embrace entire groups of them or stretch along the surface of the bone. The Haversian canal, in combination with the surrounding concentric bone plates, is considered to be the structural unit of the compact bone substance, the osteon.

Parallel to the surface of these plates, they contain layers of small star-shaped voids, continuing into numerous thin tubules - these are the so-called "bone bodies", in which there are bone cells that give rise to tubules. The tubules of the bone bodies are connected to each other and to the cavity of the Haversian canals, the internal cavities and the periosteum, and thus the entire bone tissue is permeated with a continuous system of cavities and tubules filled with cells and their processes, through which the nutrients necessary for bone life penetrate.

Fine blood vessels pass through the Haversian canals; wall of the Haversian canal and outside surface blood vessels are covered with a thin layer of endothelium, and the spaces between them serve as the lymphatic pathways of the bone.

Cancellous bone does not have Haversian canals.

9) methods for studying the skeletal system.
The bones of the skeleton can be studied in a living person by X-ray examination. The presence of calcium salts in the bones makes the bones less “transparent” to X-rays than the surrounding ones. soft tissues. Due to the unequal structure of the bones, the presence in them of a more or less thick layer of compact cortex, and inside of it the spongy substance can be seen and distinguish bones on radiographs.
X-ray (X-ray) examination is based on the property of X-rays in varying degrees penetrate through body tissues.

The degree of absorption of X-ray radiation depends on the thickness, density and physico-chemical composition of human organs and tissues, therefore, denser organs and tissues (bones, heart, liver, large vessels) are visualized on the screen (X-ray fluorescent or television) as shadows, and lung tissue due to a large number air is represented by an area of \u200b\u200bbright glow.

There are the following main radiological methods of research.

1. X-ray (gr.

skopeo- consider, observe) - x-ray examination in real time. A dynamic image appears on the screen, allowing you to study the motor function of organs (for example, vascular pulsation, gastrointestinal motility); organ structure is also visible.

2. Radiography (gr. grapho- write) - X-ray examination with the registration of a still image on a special x-ray film or photographic paper.

With digital radiography, the image is fixed in the computer's memory. Five types of radiography are used.

Full size radiography.

Fluorography (small format radiography) - radiography with a reduced image size obtained on a fluorescent screen (lat.

fluor- current, flow); it is used in preventive studies of the respiratory system.

Plain radiography - an image of the entire anatomical region.

Aiming radiography - an image of a limited area of \u200b\u200bthe organ under study.

Wilhelm Conrad Roentgen (1845-1923) - German experimental physicist, founder of radiology, discovered X-rays (X-rays) in 1895.

Serial radiography - sequential acquisition of several radiographs to study the dynamics of the process under study.

Tomography (gr. tomos- segment, layer, layer) is a layer-by-layer visualization method that provides an image of a tissue layer of a given thickness using an X-ray tube and a film cassette ( x-ray tomography) or with the connection of special counting chambers, from which electrical signals are fed to a computer (computed tomography).

Contrast fluoroscopy (or radiography) - X-ray method research based on the introduction into hollow organs (bronchi, stomach, renal pelvis and ureters, etc.) or vessels (angiography) of special (radiocontrast) substances that delay x-ray radiation, as a result of which a clear image is obtained on the screen (film) fermentation of the studied organs.

10) the structure of the bone as an organ, typical bone formations.
Bone, os, ossis, as an organ of a living organism, it consists of several tissues, the most important of which is bone.

awn(os) is an organ that is a component of the system of organs of support and movement, having a typical shape and structure, characteristic architectonics of blood vessels and nerves, built mainly of bone tissue, covered on the outside with a periosteum (periosteum) and containing bone marrow (medulla osseum) inside.

Each bone has a specific shape, size and position in the human body.

The formation of bones is significantly influenced by the conditions in which the bones develop and the functional loads that the bones experience during the life of the organism. Each bone is characterized by a certain number of sources of blood supply (arteries), the presence of certain places of their localization and the characteristic intraorgan architectonics of the vessels.

These features also apply to the nerves innervating this bone.

The composition of each bone includes several tissues that are in certain ratios, but, of course, lamellar bone tissue is the main one. Consider its structure using the example of the diaphysis of a long tubular bone.

The main part of the diaphysis of the tubular bone, located between the outer and inner surrounding plates, is made up of osteons and intercalated plates (residual osteons).

The osteon, or Haversian system, is the structural and functional unit of the bone. Osteons can be seen on thin sections or histological preparations.

The internal structure of the bone: 1 - bone tissue; 2 - osteon (reconstruction); 3 - longitudinal section of the osteon

The osteon is represented by concentrically arranged bone plates (Haversian), which, in the form of cylinders of different diameters, nested in each other, surround the Haversian canal.

In the latter, blood vessels and nerves pass. Osteons are mostly located parallel to the length of the bone, repeatedly anastomosing with each other.

The number of osteons is individual for each bone; in the femur, it is 1.8 per 1 mm2. In this case, the Haversian channel accounts for 0.2-0.3 mm2. Between the osteons are intercalary, or intermediate, plates that go in all directions.

Intercalated plates are the remaining parts of old osteons that have undergone destruction. In the bones, the processes of neoplasm and destruction of osteons are constantly taking place.

Outside bone surround several layers of general, or common, plates, which are located directly under the periosteum (periosteum).

Perforating canals (Volkmann's) pass through them, which contain blood vessels of the same name. On the border with the medullary cavity in the tubular bones is a layer of internal surrounding plates. They are permeated with numerous channels expanding into cells. The medullary cavity is lined with endosteum, which is a thin connective tissue layer containing flattened inactive osteogenic cells.

In the bone plates, having the shape of cylinders, ossein fibrils are tightly and parallel to each other.

Between the concentrically lying bone plates of osteons are osteocytes. The processes of bone cells, spreading along the tubules, pass towards the processes of neighboring osteocytes, enter into intercellular junctions, forming a spatially oriented lacunar-tubular system involved in metabolic processes.

The osteon contains up to 20 or more concentric bone plates.

In the canal of the osteon, 1-2 vessels of the microvasculature pass, unmyelinated nerve fibers, lymphatic capillaries, accompanied by layers of loose connective tissue containing osteogenic elements, including perivascular cells and osteoblasts.

The osteon channels are interconnected, with the periosteum and the medullary cavity by perforating channels, which contributes to the anastomosis of the bone vessels as a whole.

Outside, the bone is covered with a periosteum formed by fibrous connective tissue. It distinguishes between the outer (fibrous) layer and the inner (cellular) layer.

In the latter, cambial progenitor cells (preosteoblasts) are localized. The main functions of the periosteum are protective, trophic (due to the blood vessels passing through here) and participation in regeneration (due to the presence of cambial cells).

The periosteum covers the outside of the bone, with the exception of those places where articular cartilage is located and muscle tendons or ligaments are attached (on the articular surfaces, tubercles and tuberosities). The periosteum separates the bone from surrounding tissues.

It is a thin, durable film, consisting of dense connective tissue, in which blood and lymphatic vessels and nerves are located. The latter from the periosteum penetrate into the substance of the bone.

External structure of the humerus: 1 - proximal (upper) epiphysis; 2 - diaphysis (body); 3 - distal (lower) epiphysis; 4 - periosteum

The periosteum plays an important role in the development (growth in thickness) and nutrition of the bone.

Its inner osteogenic layer is the site of bone formation. The periosteum is richly innervated, therefore it is highly sensitive. The bone, deprived of the periosteum, becomes unviable, dies.

At surgical interventions on the bones for fractures, the periosteum must be preserved.

Almost all bones (with the exception of most bones of the skull) have articular surfaces for articulation with other bones.

The articular surfaces are covered not by the periosteum, but by articular cartilage (cartilage articularis). The articular cartilage in its structure is more often hyaline and less often fibrous.

Inside most bones in the cells between the plates of the spongy substance or in the medullary cavity (cavitas medullaris) is the bone marrow.

It comes in red and yellow. In fetuses and newborns, the bones contain only red (hematopoietic) bone marrow. It is a homogeneous mass of red color, rich in blood vessels, shaped elements blood and reticular tissue.

The red bone marrow also contains bone cells, osteocytes. The total amount of red bone marrow is about 1500 cm3.

In an adult, the bone marrow is partially replaced by yellow, which is mainly represented by fat cells. Only the bone marrow located within the marrow cavity is subject to replacement. It should be noted that the inside of the medullary cavity is lined with special shell, called the endosteum.

1. Long tubular (os thigh, lower leg, shoulder, forearm).

2. Short tubular (os metacarpus, metatarsus).

3. Short spongy (vertebral bodies).

4. Spongy (sternum).

5. Flat (shoulder blade).

6. Mixed (os skull base, vertebrae - spongy bodies, and processes are flat).

7. Air (upper jaw, ethmoid, wedge-shaped).

The structure of the bones .

Bone living person is a complex organ, occupies a certain position in the body, has its own shape and structure, performs its characteristic function.

Bone is made up of:

Bone tissue (occupies the main place).

2. Cartilaginous (covers only the articular surfaces of the bone).

3. Fat (yellow bone marrow).

Reticular (red bone marrow)

Outside, the bone is covered with periosteum.

Periosteum(or periosteum) - a thin two-layer connective tissue plate.

The inner layer consists of loose connective tissue, it contains osteoblasts.

They are involved in the growth of the bone in thickness and the restoration of its integrity after fractures.

The outer layer is composed of dense fibrous fibers. The periosteum is rich in blood vessels and nerves, which through thin bone tubules penetrate deep into the bone, supplying and innervating it.

Located inside the bone Bone marrow.

Bone marrow is of two types:

red bone marrow- an important organ of hematopoiesis and bone formation.

Saturated with blood vessels and blood elements. It is formed by reticular tissue, which contains hematopoietic elements (stem cells), osteoclasts (destroyers), osteoblasts.

In the prenatal period and in newborns, all bones contain red marrow.

In an adult, it is found only in the cells of the spongy substance of flat bones (sternum, skull bones, ilium), in spongy (short bones), epiphyses of tubular bones.

As blood cells mature, they enter the bloodstream and are carried throughout the body.

The yellow bone marrow is represented mainly by fat cells and degenerate cells of the reticular tissue.

Lipocytes give bone yellow. Yellow bone marrow is located in the cavity of the diaphysis of tubular bones.

Bone plates are formed from bone tissue.

If the bone plates are tightly adjacent to each other, then it turns out dense or compact bone substance.

If the bone crossbars are located loosely, forming cells, then spongy bone substance, which consists of a network of thin anastomosed bone elements - trabeculae.

Bone crossbars are not arranged randomly, but strictly regularly along the lines of compression and tension forces.

Osteon is the structural unit of bone.

Osteons consist of 2-20 cylindrical plates inserted one into the other, inside which a (Haversian) canal passes.

A lymphatic vessel, an artery and a vein pass through it, which branch out to capillaries and approach the lacunae of the Haversian system. They provide inflow and outflow of nutrients, metabolic products, CO2 and O2.

On the outer and inner surfaces of the bone, the bone plates do not form concentric cylinders, but are located around them.

These areas are pierced by Volkmann's canals through which blood vessels pass, which connect with the vessels of the Haversian canals.

Living bone contains 50% water, 12.5% protein organic matter (ossein and osseomucoid), 21.8% inorganic minerals (mainly calcium phosphate), and 15.7% fat.

Organic substances cause elasticity bones, and inorganic hardness.

Tubular bones are made up of body (diaphysis) and two ends (epiphyses). Epiphyses are proximal and distal.

On the border between the diaphysis and the epiphysis is located metaepiphyseal cartilage due to which the bone grows in length.

Complete replacement of this cartilage with bone occurs in women by the age of 18-20, and in men by the age of 23-25. From that time on, the growth of the skeleton, and hence the person, stops.

The epiphyses are built of spongy bone substance, in the cells of which there is red bone marrow. Outside, the epiphyses are covered articular hyaline cartilage.

The diaphysis consists of a compact bone substance.

Inside the diaphysis is medullary cavity It contains yellow bone marrow. Outside, the diaphysis is covered periosteum. The periosteum of the diaphysis gradually passes into the perichondrium of the epiphyses.

Spongy bone consists of 2 compact bone plates, between which there is a layer of spongy substance.

Red bone marrow is located in spongy cells.

Bones united in the skeleton (skeletos) - from Greek, means dried.

3.
Types of bones and their connections

The human skeleton contains over 200 bones.
All bones of the skeleton are divided into four types according to their structure, origin and functions: Tubular (shoulder, ulna, radius, femur, tibia, fibula) long bones in the form of a tube, having a canal inside with yellow bone marrow.

Provide fast and diverse limb movements.
Spongy (long: ribs, sternum; short: bones of the wrist, tarsus) - bones, mainly consisting of a spongy substance covered with a thin layer of compact substance. They contain red bone marrow, which provides the function of hematopoiesis.
Flat (shoulder blades, skull bones) - bones, the width of which prevails over the thickness for protection internal organs.

They consist of plates of compact substance and a thin layer of spongy substance.
Mixed - consist of several parts that have different structure, origin and functions (the vertebral body is a spongy bone, and its processes are flat bones).

Various types of bones provide the functions of parts of the skeleton.
A fixed (continuous) connection is a fusion or fastening of connective tissue to perform protective function(the connection of the bones of the roof of the skull to protect the brain).
A semi-movable connection through elastic cartilage pads form bones that perform both protective and motor function(connections of the vertebrae by intervertebral cartilaginous discs, ribs with the sternum and thoracic vertebrae)
Mobile (discontinuous) connection due to the joints have bones that provide movement of the body.

Different joints provide different directions of movement.

articular surfaces of articulating bones; articular (synovial) fluid.
The articular surfaces correspond to each other in shape and are covered with hyaline cartilage.

The joint bag forms a sealed cavity with synovial fluid. This promotes gliding and protects the bone from abrasion.
Illustrations:
http://www.ebio.ru/che04.html

What does arthrology study? The section of anatomy devoted to the doctrine of the connection of bones is called arthrology (from the Greek. arthron - “joint”). Bone joints unite the bones of the skeleton into a single whole, holding them close to each other and providing them with more or less mobility. Bone joints have a different structure and have such physical properties, as strength, elasticity and mobility, which is associated with the function they perform.

CLASSIFICATION OF BONE JOINTS. Although bone joints vary greatly in structure and function, they can be divided into three types:
1.

Continuous connections (synarthrosis) are characterized by the fact that the bones are connected by a continuous layer of connective tissue (dense connective, cartilage or bone). There is no gap or cavity between the connecting surfaces.

2. Semi-discontinuous connections (hemiarthrosis), or symphyses - this is a transitional form from continuous connections to discontinuous ones.

They are characterized by the presence in the cartilaginous layer located between the connecting surfaces, a small gap filled with fluid.

Such compounds are characterized by low mobility.

3. Discontinuous connections (diarrhosis), or joints, are characterized by the fact that there is a gap between the connecting surfaces and the bones can move relative to each other.

Such compounds are characterized by significant mobility.

Continuous connections (synarthrosis). Continuous connections have greater elasticity, strength and, as a rule, limited mobility.

Depending on the type of connective tissue located between the articulating surfaces, there are three types of continuous connections:
Fibrous connections, or syndesmoses, are strong bone connections with the help of dense fibrous connective tissue, which fuses with the periosteum of the connecting bones and passes into it without a clear boundary.

Syndesmoses include: ligaments, membranes, sutures and driving in (Fig. 63).

Ligaments serve mainly to strengthen the joints of bones, but they can limit movement in them. Ligaments are built from dense connective tissue rich in collagen fibers.

However, there are bundles that contain significant amount elastic fibers (for example, yellow ligaments located between the arches of the vertebrae).

Membranes (interosseous membranes) connect adjacent bones for a considerable length, for example, they are stretched between the diaphyses of the bones of the forearm and lower leg and close some bone openings, for example, the obturator foramen of the pelvic bone.

Often, the interosseous membranes serve as the site of the beginning of the muscle.

seams- a kind of fibrous connection, in which there is a narrow connective tissue layer between the edges of the connecting bones. The connection of bones by seams is found only in the skull. Depending on the configuration of the edges, there are:
- jagged sutures (in the roof of the skull);
- scaly suture (between the scales of the temporal bone and parietal bone);
- flat sutures (in the facial skull).

Impaction is a dento-alveolar connection, in which between the root of the tooth and the dental alveolus there is a narrow layer of connective tissue - the periodontium.

Cartilaginous joints, or synchondrosis, are joints of bones with the help of cartilaginous tissue (Fig.

64). This type of connection is characterized by high strength, low mobility and elasticity due to the elastic properties of cartilage.

Synchondroses are permanent and temporary:
1.

Permanent synchondrosis is such a type a connection in which cartilage exists between the connecting bones throughout life (for example, between the pyramid of the temporal bone and the occipital bone).
2.

Temporary synchondrosis is observed in cases where the cartilaginous layer between the bones is preserved until a certain age (for example, between the bones of the pelvis), in the future, the cartilage is replaced by bone tissue.

Bone joints, or synostoses, are the joints of bones with the help of bone tissue.

Synostoses are formed as a result of the replacement of bone tissue with other types of bone joints: syndesmoses (for example, frontal syndesmosis), synchondroses (for example, sphenoid-occipital synchondrosis) and symphyses (mandibular symphysis).

Semi-discontinuous connections (symphyses). Semi-discontinuous joints, or symphyses, include fibrous or cartilaginous joints, in the thickness of which there is a small cavity in the form of a narrow slit (Fig.

65), filled with synovial fluid. Such a connection is not covered by a capsule from the outside, and the inner surface of the gap is not lined with a synovial membrane.

In these joints, small displacements of the articulating bones relative to each other are possible. Symphyses meet in the sternum - symphysis of the handle of the sternum, in spinal column- intervertebral symphysis and in the pelvis - pubic symphysis.

Lesgaft, the formation of a particular joint is also due to the function assigned to this part of the skeleton. In the links of the skeleton, where mobility is necessary, diarthroses are formed (on the limbs); where protection is needed, synarthrosis (connection of the bones of the skull) is formed; in places experiencing a support load, continuous connections are formed, or inactive diarthrosis (joints of the pelvic bones).

Discontinuous connections (joints). Discontinuous joints, or joints, are the most perfect types of connection of bones.

They are distinguished by great mobility, a variety of movements.

Mandatory elements of the joint (Fig. 66):

1. Surface joint. At least two articular surfaces are involved in the formation of a joint. In most cases, they correspond to each other, i.e.

are congruent. If one articular surface is convex (head), then the other is concave (articular cavity). In a number of cases, these surfaces do not correspond to each other either in shape or in size - they are incongruent. The articular surfaces are usually covered with hyaline cartilage. Exceptions are the articular surfaces in the sternoclavicular and temporomandibular joints - they are covered with fibrous cartilage.

Articular cartilage smooths out the roughness of the articular surfaces, and also absorb shocks during movement. The greater the load experienced by the joint under the influence of gravity, the greater the thickness of the articular cartilage.

2. The articular capsule is attached to the articulating bones near the edges of the articular surfaces. It is firmly fused with the periosteum, forming a closed articular cavity.

The joint capsule consists of two layers. The outer layer is formed by a fibrous membrane, built from dense fibrous connective tissue.

In some places, it forms thickenings - ligaments that can be located outside the capsule - extracapsular ligaments and in the thickness of the capsule - intracapsular ligaments.

Extracapsular ligaments are part of the capsule, making up with it one inseparable whole (for example, the coraco-brachial ligament). Sometimes there are more or less isolated ligaments, such as the collateral peroneal ligament of the knee joint.

Intracapsular ligaments lie in the joint cavity, moving from one bone to another.

They consist of fibrous tissue and are covered by a synovial membrane (for example, the ligament of the femoral head). Ligaments, developing in certain places of the capsule, increase the strength of the joint, depending on the nature and amplitude of movements, playing the role of brakes.

The inner layer is formed by the synovial membrane, built from loose fibrous connective tissue.

It lines the fibrous membrane from the inside and continues to the surface of the bone, not covered by articular cartilage. The synovial membrane has small outgrowths - synovial villi, which are very rich in blood vessels that secrete synovial fluid.

3. The articular cavity is a slit-like space between the articular surfaces covered with cartilage. It is bounded by the synovial membrane of the joint capsule and contains synovial fluid.

Inside the articular cavity, negative atmospheric pressure prevents the divergence of the articular surfaces.

4. Synovial fluid is secreted by the synovial membrane of the capsule. It is a viscous transparent liquid that lubricates the articular surfaces of bones covered with cartilage and reduces their friction against each other.

Auxiliary elements of the joint (Fig.

67):

1. Articular discs and menisci are cartilage plates various shapes located between not fully corresponding to each other (incongruent) articular surfaces.

Disks and menisci are able to move with movement. They smooth the articulating surfaces, make them congruent, absorb shocks and shocks when moving. There are discs in the sternoclavicular and temporomandibular joints, and menisci in the knee joint.

2. articular lips located along the edge of the concave articular surface, deepening and supplementing it. With their base they are attached to the edge of the articular surface, and with their inner concave surface they face the joint cavity.

Articular lips increase the congruence of the joints and contribute to a more even pressure of one bone on another. Articular lips are present in the shoulder and hip joints.

3. Synovial folds and bags. In places where the articulating surfaces are incongruent, the synovial membrane usually forms synovial folds (for example, in the knee joint).

In the thinned places of the articular capsule, the synovial membrane forms bag-like protrusions or eversion - synovial bags, which are located around the tendons or under the muscles lying near the joint. Being filled with synovial fluid, they facilitate the friction of tendons and muscles during movement.

Main part musculoskeletal system human - a skeleton consisting of more than two hundred different bones. It enables people to move, supports internal organs. In addition, they are a concentration of minerals, as well as a shell that contains bone marrow.

Skeleton Functions

The various types of bones that make up the human skeleton primarily act as a means of supporting and supporting the body. Some of them serve as a receptacle for certain internal organs, such as the brain, located in the bones of the skull, lungs and heart, located in the chest, and others.

We also owe the ability to make various movements and move around to our own skeleton. In addition, human bones contain up to 99% of the calcium found in the body. Red bone marrow is of great importance in human life. It is located in the skull, spine, sternum, collarbone and some other bones. Bone marrow produces blood cells: erythrocytes, platelets and leukocytes.

The structure of the bone

The anatomy of a bone has extraordinary properties that determine its strength. The skeleton must withstand a load of 60-70 kg - this is the average weight of a person. In addition, the bones of the trunk and limbs work as levers that allow us to move and perform various activities. This is achieved due to their amazing composition.

Bones consist of organic (up to 35%) and inorganic (up to 65%) substances. The former include protein, mainly collagen, which determines the firmness and elasticity of tissues. Inorganic substances - calcium and phosphorus salts - are responsible for hardness. The combination of these elements gives the bones a special strength, comparable, for example, with cast iron. They can be perfectly preserved for many years, as evidenced by the results of various excavations. can disappear as a result of calcination of tissues, as well as when they are exposed to sulfuric acid. Minerals are very resistant to external influences.

Human bones are permeated with special tubules through which blood vessels pass. In their structure, it is customary to distinguish between compact and spongy substances. Their ratio is determined by the location of the bone in the human body, as well as the functions it performs. In areas where resistance to heavy loads, the main one is a dense compact substance. Such a bone consists of many cylindrical plates placed one inside the other. The spongy substance in its appearance resembles a honeycomb. In its cavities is red bone marrow, and in adults it is also yellow, in which fat cells are concentrated. The bone is covered by a special connective tissue sheath - the periosteum. It is permeated with nerves and blood vessels.

Bone classification

There are various classifications that cover all types of bones of the human skeleton, depending on their location, structure and functions.

1. By location:

cranial bones;
body bones;
limb bones.

2. The following types of bones are distinguished by development:

primary (appear from connective tissue);
secondary (formed from cartilage);
mixed.

3. The following types of human bones are distinguished by structure:

tubular;
spongy;
flat;
mixed.

Thus, different types of bones are known to science. The table makes it possible to more clearly present this classification.

tubular bones

Tubular long bones are composed of both dense and spongy matter. They can be divided into several parts. The middle of the bone is formed by a compact substance and has an elongated tubular shape. This area is called the diaphysis. Its cavities first contain red bone marrow, which is gradually replaced by yellow, containing fat cells.

At the ends of the tubular bone is the epiphysis - this is the area formed by the spongy substance. Red bone marrow is placed inside it. The area between the diaphysis and the epiphysis is called the metaphysis.

During the period of active growth of children and adolescents, it contains cartilage, due to which the bone grows. Over time, the anatomy of the bone changes, the metaphysis completely turns into bone tissue. The long ones include the thigh, shoulder, bones of the forearm. Tubular small bones have a slightly different structure. They have only one true epiphysis and, accordingly, one metaphysis. These bones include the phalanges of the fingers, the bones of the metatarsus. They function as short levers of movement.

Spongy types of bones. Pictures

The name of the bones often indicates their structure. For example, spongy bones are formed from a spongy substance covered with a thin layer of compact. They do not have developed cavities, so the red bone marrow is placed in small cells. Spongy bones are also long and short. The former include, for example, the sternum and ribs. Short spongy bones are involved in the work of muscles and are a kind of auxiliary mechanism. These include vertebrae.

flat bones

These types of human bones, depending on their location, have a different structure and perform certain functions. The bones of the skull are primarily protection for the brain. They are formed by two thin plates of dense substance, between which is located spongy. It has openings for veins. The flat bones of the skull develop from connective tissue. The scapula and also belong to the type of flat bones. They are formed almost entirely from a spongy substance that develops from cartilage tissue. These types of bones perform the function of not only protection, but also support.

mixed dice

Mixed bones are a combination of flat and short spongy or tubular bones. They develop different ways and perform those functions that are necessary in a particular part of the human skeleton. Such types of bones as mixed are found in the body of the temporal bone, vertebrae. These include, for example, the clavicle.

cartilage tissue

Cartilage has an elastic structure. It forms the auricles, nose, some parts of the ribs. It is also located between the vertebrae, as it perfectly resists the deforming force of loads. It has high strength, excellent resistance to abrasion and crushing.

Connection of bones

There are different ones that determine the degree of their mobility. The bones of the skull, for example, have a thin layer of connective tissue. However, they are absolutely immobile. Such a connection is called fibrous. Between the vertebrae are also areas of connective or cartilaginous tissue. Such a connection is called semi-movable, since the bones, although limited, can move a little.

Joints that form synovial joints have the highest mobility. The bones in the joint bag are held by ligaments. These fabrics are both flexible and durable. In order to reduce friction, a special oily fluid is located in the joint - synovia. It envelops the ends of the bones, covered with cartilage, and facilitates their movement.

There are several types of joints. As the name of the bones is determined by their structure, so the name of the joints depends on the shape of the bones that they connect. Each type allows you to perform certain movements:

Ball joint. With this connection, the bones move in many directions at once. These joints include the shoulder and hip joints.
Block joint (elbow, knee). Assumes movement exclusively in one plane.
Cylindrical joint allows the bones to move relative to each other.
Flat joint. It is inactive, provides movements of a small scope between two bones.
Ellipsoidal joint. Thus connected, for example, radius with the bones of the wrist. They can move from side to side within the same plane.
Thanks to saddle joint thumb hands can move in different planes.

The impact of physical activity

Degree physical activity has a significant effect on the shape and structure of bones. At different people the same bone can have its own characteristics. With constant impressive physical exertion, the compact substance thickens, and the cavity, on the contrary, shrinks in size.

Negatively affects the condition of the bones long stay in bed, sedentary lifestyle. Fabrics become thinner, lose their strength and elasticity, become brittle.

Changes under the influence of physical activity and the shape of the bones. Those places where muscles act on them can become flatter. With particularly intense pressure, small depressions may even occur over time. In areas of strong stretching, where ligaments act on the bones, thickenings, various irregularities, and tubercles can form. Especially such changes are typical for people professionally involved in sports.

A variety of injuries, especially those received in adulthood, also affect the shape of the bones. When the fracture grows together, all kinds of deformations can occur, which often adversely affect the effective management of one's body.

Age-related changes in bones

In different periods of a person's life, the structure of his bones is not the same. In infants, almost all bones consist of a spongy substance, which is covered with a thin layer of compact. Their continuous, up to a certain time, growth is achieved due to an increase in the size of cartilage, which is gradually replaced by bone tissue. This transformation continues until the age of 20 in women and up to about 25 in men.

The younger the person, the more organic matter is contained in the tissues of his bones. Therefore, in early age they are elastic and flexible. In an adult, the volume of mineral compounds in bone tissue is up to 70%. At the same time, from a certain point, a decrease in the amount of calcium and phosphorus salts begins. Bones become brittle, so older people often experience fractures even as a result of a minor injury or a careless sudden movement.

These fractures take a long time to heal. There is a special disease characteristic of the elderly, especially women - osteoporosis. For its prevention, upon reaching the age of 50, it is necessary to consult a doctor for some research to assess the condition of the bone tissue. With appropriate treatment, the risk of fractures is significantly reduced and the healing time is shortened.

Examples of flat human bones. Bones are categorized according to their shape and structure.

Types of bones in the adult body

How many bones are in the human body?

Functions of the human skeleton

Departments of the skeleton

limb skeleton

Sex differences

Lecture: Classification of bones according to shape and internal structure. Classification of bones.

3. Types of bones and their connections

Skeleton Functions

The structure of the bone

Bone classification

tubular bones

Spongy types of bones. Pictures

flat bones

mixed dice

cartilage tissue

Connection of bones

The impact of physical activity

Age-related changes in bones

Recent Entries

3.
Types of bones and their connections