Composition of cartilage tissue. Cartilage tissue, its types, structure and significance for the animal body

Which helps ensure its mobility, or a separate anatomical formation outside the skeleton. In direct connection with the bone are articular cartilages (the most representative group), intervertebral discs, cartilages of the ear, nose, and pubic symphysis. Individual anatomical formations make up the group of cartilage of the airways (larynx, trachea, bronchi), and the stroma of the heart.

Cartilage performs integrative-buffering, shock-absorbing, shape-supporting functions, and participates in the development and growth of bones. Biomechanical functions are carried out due to the elastic properties of cartilage.

The bulk of cartilage is represented by cartilaginous tissue. It consists of non-cellular and cellular elements. Non-cellular elements are the determining functional unit of cartilage tissue and make up the main part. This part is conventionally divided into fibrous collagen and elastic structures and. The basis of collagen structures is collagen protein, from which all fibrous structures of cartilage are built: molecules, microfibrils, fibrils, fibers. Elastic structures are present in some cartilages (auricle, epiglottis, perichondrium) in the form of elastin and elastic glycoprotein molecules, elastic fibrils and fibers, plastic glycoprotein microfibrils, amorphous elastin.

The fibrous structures and cellular elements of cartilage are surrounded by the ground substance and integrative-buffer metabolic environment connective tissue, which has a gel-like consistency. Its main components are proteoglycans and the water they retain, through which all metabolic processes are carried out. It also provides the shock-absorbing function of cartilage.

An important part of cartilage tissue is the interstitial space (interfibrous and intercellular), which represents unified system peculiar channels, the walls of which are formed by fibrous structures. This channel is filled with the main substance and is the second link of microcirculation. Interstitial fluid moves along it under the influence of mechanical pressure, capillary and osmotic forces, which also ensures the biomechanical function of cartilage tissue. The channels have the shape of tubes, slits of rounded cavities.

The cellular elements of cartilage tissue create cartilage and carry out its constant renewal and restoration. Among the cartilage cells, cambial cells are distinguished cartilage cells, chondroblasts and chondrocytes.

There are three types of cartilage - hyaline, elastic and fibrous. The basis for the isolation of hyaline cartilages is their external - resemble. This group includes cartilages of the articular, airways, and nose. Elastic cartilages are distinguished by the qualitative composition of their fibrous structures, although in appearance they are identical to hyaline cartilages. These are the cartilages of the ear and epiglottis. Fibrous cartilages are identified according to the characteristic structural organization. Their connective tissue skeleton is mainly built of collagen fibers, unlike other cartilages, where the basis is made up of collagen fibrils.

Chest damage is noted as a result of the action of physical (mechanical, thermal, etc.), chemical and other traumatic agents. With mechanical damage to the bone, the integrity of the perichondrium (see Perichondritis), part of the cartilaginous covering of the articular end of the bone, for example, transchondral (see Knee joint) may be damaged. , cartilaginous bone growth zone ( - see Fractures) , individual cartilages (nose, larynx, ear, ribs, etc.). X. can be damaged as a result of prolonged action of weak mechanical agents (see Microtrauma) .

Chest lesions are noted in many dystrophic processes (see Osteoarthritis , Osteochondrosis , Osteochondropathies (Osteochondropathies)) , metabolic disorders (for example, Kashin-Beck disease (Kashina-Beck disease) , Ochronose) . In some cases (sepsis of various etiologies) they are accompanied by damage to cartilaginous structures.

Chondroma accounts for 10-15% of all benign bone tumors. It occurs mainly at the age of 20-30 years in people of both sexes. It can be located both in the central and peripheral parts of the bone and is accordingly designated as “” and “”. Favorite - metacarpal and metatarsal bones, less often - long tubular bones and pelvic bones. In most cases, chondromas are multiple. Solitary tumors are more common in long tubular bones and pelvic bones. Chondroma causes few clinical symptoms, which is due to its slow growth. When the hands and feet are affected, there are small, slowly increasing thickenings of the bones. When localized in the distal parts of the extremities, there are pathological ones.

Osteochondroma (osteochondroma) consists of a bone outgrowth covered with a layer of cartilage. It is usually localized in the area of the metaphyses of long tubular bones, on the ribs, and pelvic bones. can be solitary or multiple, sometimes it is hereditary. They may not appear clinically. Upon reaching large sizes deformation of the affected bone and pain occur due to pressure on.

Chondroblastoma is extremely rare, predominantly in humans young. Localized in the area of the epiphyseal-cartilaginous plate of long tubular bones and the diaphysis. atypical - moderate pain, slight swelling in the area of the affected bone, (restriction of movement in the adjacent joint.

Chondromyxoid fibroma is rare. Occurs in young people. Most often located in the bones that form. Clinically, it manifests itself as minor pain, restrictions of movement, and, less commonly, palpable swelling.

The leading diagnostic method is x-ray. Recognizing multiple chondromas of the hands and feet usually does not cause difficulties. Long bone chondromas, chondroblastomas, and chondromyxoid fibromas are more difficult to diagnose. They have to be differentiated from slow-growing chondrosarcomas, giant cell tumors and other bone lesions. Diagnostic difficulties are overcome by histological examination of material obtained from the lesion. The only treatment method for these tumors is surgical. Special attention chondromas of long tubular bones and osteochondromas require, since they are more likely than other benign tumors to undergo malignancy after non-radical operations. For enchondroma of the long tubular bone, a segmental one is indicated. Small bone chondromas require removal of all affected bone. after a radical operation, favorable.

Of great importance for resolving the issue of the onset of malignancy is monitoring the dynamics of clinical and radiological signs. The main symptom of malignancy of chondroma is a sudden increase in the size of a previously long-existing tumor. In doubtful cases, repeated X-ray examinations should be carried out monthly.

Chondrosarcoma is relatively common, accounting for 12-18% of all bone sarcomas. It is observed mainly at the age of 25-60 years, in men it is 2 times more common. The predominant localization is the pelvic bones, upper limb girdles, and ribs. The proximal articular cones of the femur and humerus are often affected. In 8-10% of patients, chondrosarcoma develops secondary to previous pathological processes: chondromas, osteochondral exostoses, dyschondroplasia (Ollier), deforming osteosis (Paget's disease) .

The main symptoms of primary chondrosarcoma are the presence of a tumor and pain, which intensify as the tumor grows. In terms of clinical course and X-ray morphological manifestations, chondrosarcomas differ significantly from each other, which is due to the peculiarities of their microscopic structure. Highly differentiated tumors are characterized by long-lasting tumors with low severity of symptoms, which is typical for people over 30 years of age. In anaplastic chonrosarcomas (more often in young people), the duration of development of symptoms does not exceed 3 months.

The diagnosis is established taking into account clinical and radiological signs and morphological data. Volume surgical intervention depends on the location and degree of malignancy of the tumor. With 1-2 degrees of malignancy, segmental resection of the tubular bone with endoprosthetics is possible. In the case of the anaplastic variant, especially in young people, the limbs are indicated. For well-differentiated chondrosarcomas, the 5-year survival rate is up to 90%. In the case of the anaplastic variant, the prognosis is unfavorable - 5% of patients survive 5 years.

Bibliography: Histology, ed. Yu.I. Afanasyev and N.A. Yurina, s. 310, M., 1989; Clinical, ed. N.N. Blokhin and B.E. Peterson, p. 250, M., 1971; Knysh I.T., Korolev V.I. and Tolstopyatov B.A. from cartilage tissue, Kyiv, 1986; Pavlova V.N. etc. Cartilage. M., 1988; Pathoanatomical tumors of humans, ed. N.A. Kraevsky et al., p. 397, M., 1982; Trapeznikov N.N. and others. Bone tumors, M., 1986; Ham A. and Cormack D. Histology, . from English, vol. 3, M., 1983.

II (cartilago)

an anatomical formation consisting of cartilage tissue and performing a supporting function.

1. Small medical encyclopedia. - M.: Medical encyclopedia. 1991-96 2. First medical care. - M.: Great Russian Encyclopedia. 1994 3. Encyclopedic Dictionary medical terms. - M.: Soviet Encyclopedia. - 1982-1984.

Synonyms:

basis musculoskeletal system are cartilaginous tissues. It is also part of the facial structures, becoming the site of attachment of muscles and ligaments. Histology of cartilage is not presented a large number cellular structures, fibrous formations and nutrients. This ensures sufficient shock-absorbing function.

What does it represent?

Cartilage is a type of connective tissue. The structural features are increased elasticity and density, due to which it is able to perform a supporting and mechanical function. Articular cartilage consists of cells called chondrocytes and a ground substance containing fibers that provide the elasticity of the cartilage. Cells in the thickness of these structures form groups or are located separately. The location is usually near bones.

Types of cartilage

Depending on the characteristics of the structure and localization in the human body, there is the following classification of cartilage tissue:

Hyaline cartilage contains chondrocytes arranged in the form of rosettes. The intercellular substance is larger in volume than the fibrous substance, and the threads are represented only by collagen.
Elastic cartilage contains two types of fibers - collagen and elastic, and the cells are arranged in columns or columns. This type of fabric has less density and transparency, but has sufficient elasticity. This matter makes up the cartilage of the face, as well as the structures of the secondary formations in the bronchi.
Fibrous cartilage is a connective tissue that functions as strong shock-absorbing elements and contains a significant amount of fibers. The localization of the fibrous substance is throughout the musculoskeletal system.

Properties and structural features of cartilage tissue

The histological specimen shows that the tissue cells are loosely located, surrounded by an abundance of intercellular substance.

All types of cartilage tissue are capable of absorbing and counteracting the compressive forces that arise during movement and load. This ensures an even distribution of gravity and reduces the load on the bone, which stops its destruction. Skeletal areas where friction processes constantly occur are also covered with cartilage, which helps protect their surfaces from excessive wear. The histology of this type of tissue differs from other structures in the large amount of intercellular substance, and the cells are loosely located in it, form clusters or are found separately. The main substance of the cartilage structure is involved in the processes of carbohydrate metabolism in the body.

This type of material in the human body, like others, contains cells and intercellular substance of cartilage. Feature in not large quantities cellular structures, which ensures the properties of the tissue. Mature cartilage is a loose structure. Elastic and collagen fibers perform a supporting function in it. The general structural plan includes only 20% of cells, and the rest is fibers and amorphous matter. This is due to the fact that, due to dynamic load, the vascular bed of the tissue is weakly expressed and therefore it is forced to be nourished by the main substance of the cartilaginous tissue. In addition, the amount of moisture contained in it performs shock-absorbing functions, smoothly relieving tension in bone tissue.

What are they made of?

The trachea and bronchi are composed of hyaline cartilage.

Each type of cartilage has unique properties, which is caused by the difference in location. The structure of hyaline cartilage differs from the rest in the smaller number of fibers and greater filling with amorphous substance. In this regard, it is not able to withstand heavy loads, since its tissues are destroyed by the friction of bones, however, it has a rather dense and solid structure. Therefore, it is characteristic that the bronchi, trachea and larynx consist of this type of cartilage. Skeletal and musculoskeletal structures are formed predominantly by fibrous matter. Its variety includes part of the ligaments connected to hyaline cartilage. The elastic structure occupies an intermediate location relative to these two tissues.

Cellular composition

Chondrocytes do not have a clear and ordered structure, but are more often located completely chaotically. Sometimes their clusters resemble islands with large areas of absence of cellular elements. In this case, a mature type of cell and a young one, called chondroblasts, are located together. They are formed by the perichondrium and have interstitial growth, and during their development they produce various substances.

Chondrocytes are the source of components of the intercellular space, it is thanks to them that such chemical table elements in the composition of an amorphous substance:

Hyaluronic acid is contained in an amorphous substance.

proteins;
glycosaminoglycans;
proteoglycans;
hyaluronic acid.

During the embryonic period, most bones are hyaline tissue.

The structure of the intercellular substance

It consists of two parts - fibers and an amorphous substance. In this case, fibrillar structures are located chaotically in the tissue. The histology of cartilage is influenced by its production by cells chemicals, responsible for density, transparency and elasticity. The structural features of hyaline cartilage consist in the presence of only collagen fibers in its composition. If an insufficient amount of hyaluronic acid is released, it destroys tissues due to degenerative processes in them.

Blood flow and nerves

The structures of cartilage tissue do not have nerve endings. Pain reactions in them are represented only with the help of bone elements, while the cartilage will already be destroyed. This causes a large number of untreated diseases of this tissue. There are few nerve fibers on the surface of the perichondrium. The blood supply is poor and the vessels do not penetrate deep into the cartilage. That's why nutrients enter cells through the main substance.

Functions of structures

The auricle is formed from this tissue.

Cartilage is the connecting part of the human musculoskeletal system, but is sometimes found in other parts of the body. The histogenesis of cartilage tissue goes through several stages of development, due to which it is able to provide support while at the same time being completely elastic. They are also part of the external formations of the body such as the cartilage of the nose and ears. Ligaments and tendons are attached to them to the bone.

Age-related changes and diseases

The structure of cartilage tissue changes with age. The reasons for this lie in the insufficient supply of nutrients to it; as a result of disturbances in trophism, diseases arise that can destroy fibrous structures and cause cell degeneration. A young body has a much larger supply of fluid, so these cells have sufficient nutrition. However age-related changes cause “drying out” and ossification. Inflammation due to bacterial or viral agents can cause cartilage degeneration. Such changes are called “chondrosis”. At the same time, it becomes less smooth and is unable to perform its functions, as its nature changes.

Signs that the tissue has been destroyed are visible during histology analysis.

How to eliminate inflammatory and age-related changes?

To cure cartilage, drugs are used that can restore the independent development of cartilage tissue. These include chondroprotectors, vitamins and products that contain hyaluronic acid. Important proper diet with a sufficient amount of protein, because it is a stimulator of body regeneration. It is indicated to keep the body in good shape, because excess body weight and insufficient physical activity cause destruction of structures.

Cartilaginous tissue (textus cartilaginus) forms articular cartilage, intervertebral discs, cartilage of the larynx, trachea, bronchi, and external nose. Cartilage tissue consists of cartilage cells (chondroblasts and chondrocytes) and dense, elastic intercellular substance.

Cartilage tissue contains about 70-80% water, 10-15% organic matter, 4-7% salts. About 50-70% of the dry matter of cartilage tissue is collagen. The intercellular substance (matrix), produced by cartilage cells, consists of complex compounds that include proteoglycans. hyaluronic acid, glycosaminoglycan molecules. There are two types of cells in cartilage tissue: chondroblasts (from the Greek chondros - cartilage) and chondrocytes.

Chondroblasts are young round or ovoid cells capable of mitotic division. They produce components of the intercellular substance of cartilage: proteoglycans, glycoproteins, collagen, elastin. The cytolemma of chondroblasts forms many microvilli. The cytoplasm is rich in RNA, a well-developed endoplasmic reticulum (granular and non-granular), Golgi complex, mitochondria, lysosomes, and glycogen granules. The chondroblast nucleus, rich in active chromatin, has 1-2 nucleoli.

Chondrocytes are mature large cells of cartilage tissue. They are round, oval or polygonal, with processes and developed organelles. Chondrocytes are located in cavities - lacunae, surrounded by intercellular substance. If there is one cell in a lacuna, then such a lacuna is called primary. Most often, the cells are located in the form of isogenic groups (2-3 cells) occupying the cavity of the secondary lacuna. The walls of the lacuna consist of two layers: the outer layer, formed by collagen fibers, and the inner layer, consisting of aggregates of proteoglycans that come into contact with the glycocalyx of cartilage cells.

The structural and functional unit of cartilage is the chondrone, formed by a cell or an isogenic group of cells, a pericellular matrix and a lacuna capsule.

Nutrition of cartilage tissue occurs through the diffusion of substances from the blood vessels of the perichondrium. Nutrients penetrate into the tissue of articular cartilage from the synovial fluid or from the vessels of the adjacent bone. Nerve fibers are also localized in the perichondrium, from where individual branches of the soft nerve fibers can penetrate into the cartilage tissue.

In accordance with the structural features of cartilage tissue, three types of cartilage are distinguished: hyaline, fibrous and elastic cartilage.

Hyaline cartilage, from which in humans the cartilage of the respiratory tract, thoracic ends of the ribs and articular surfaces of bones is formed. In a light microscope, its main substance appears homogeneous. Cartilage cells or isogenic groups of them are surrounded by an oxyphilic capsule. In differentiated areas of cartilage, a basophilic zone adjacent to the capsule and an oxyphilic zone located outside it are distinguished; Collectively, these zones form the cellular territory, or chondrin ball. The complex of chondrocytes with the chondrinic ball is usually taken to be the functional unit of cartilage tissue - the chondrone. The main substance between chondrons is called interterritorial spaces.
Elastic cartilage(synonym: reticular, elastic) differs from hyaline in the presence of branching networks of elastic fibers in the ground substance. The cartilage of the auricle, epiglottis, Wrisberg and Santorini cartilages of the larynx are built from it.
Fibrous cartilage(synonym for connective tissue) is located in the places of transition of dense fibrous connective tissue into hyaline cartilage and differs from the latter in the presence of real collagen fibers in the main substance.

7. Bone tissue - location, structure, functions

Bone tissue is a type of connective tissue and consists of cells and intercellular substance, which contains a large amount of mineral salts, mainly calcium phosphate. Minerals make up 70% of bone tissue, organic substances – 30%.

Functions of bone tissue:

1) supporting;

2) mechanical;

3) protective (mechanical protection);

4) participation in the mineral metabolism of the body (calcium and phosphorus depot).

Bone cells - osteoblasts, osteocytes, osteoclasts. The main cells in formed bone tissue are osteocytes. These are process-shaped cells with a large nucleus and weakly expressed cytoplasm (nuclear-type cells). Cell bodies are localized in bone cavities (lacunae), and processes are located in bone tubules. Numerous bone tubules, anastomosing with each other, penetrate the bone tissue, communicating with the perivascular space, forming a bone tissue drainage system. This drainage system contains tissue fluid, through which metabolism is ensured not only between cells and tissue fluid, but also in the intercellular substance.

Osteocytes are the definitive form of cells and do not divide. They are formed from osteoblasts.

Osteoblasts found only in developing bone tissue. In formed bone tissue they are usually contained in an inactive form in the periosteum. In developing bone tissue, osteoblasts cover the periphery of each bone plate, tightly adjacent to each other.

The shape of these cells can be cubic, prismatic and angular. The cytoplasm of osteoblasts contains a well-developed endoplasmic reticulum, lamellar Golgi complex, many mitochondria, which indicates the high synthetic activity of these cells. Osteoblasts synthesize collagen and glycosaminoglycans, which are then released into the intercellular space. Due to these components, the organic matrix of bone tissue is formed.

These cells provide mineralization of the intercellular substance by secreting calcium salts. Gradually releasing intercellular substance, they become immured and turn into osteocytes. In this case, intracellular organelles are significantly reduced, synthetic and secretory activity is reduced, and the functional activity characteristic of osteocytes is preserved. Osteoblasts, localized in the cambial layer of the periosteum, are in an inactive state, and their synthetic and transport organelles are poorly developed. When these cells are irritated (in case of injuries, bone fractures, etc.), granular EPS and lamellar complex quickly develop in the cytoplasm, active synthesis and release of collagen and glycosaminoglycans occurs, the formation of an organic matrix (bone callus), and then the formation of definitive bone fabrics. In this way, due to the activity of osteoblasts of the periosteum, bone regeneration occurs when they are damaged.

Osteoclasts– bone-destructive cells are absent in formed bone tissue, but are contained in the periosteum and in places of destruction and restructuring of bone tissue. Since local processes of bone tissue restructuring are continuously carried out during ontogenesis, osteoclasts are also necessarily present in these places. During the process of embryonic osteohistogenesis, these cells play a very important role and are present in large numbers. Osteoclasts have a characteristic morphology: these cells are multinucleated (3 – 5 or more nuclei), have a fairly large size (about 90 µm) and characteristic shape– oval, but the part of the cell adjacent to the bone tissue has a flat shape. In the flat part, two zones can be distinguished: the central (corrugated part, containing numerous folds and processes, and the peripheral part (transparent) in close contact with the bone tissue. In the cytoplasm of the cell, under the nuclei, there are numerous lysosomes and vacuoles of various sizes.

The functional activity of the osteoclast is manifested as follows: in the central (corrugated) zone of the cell base, carbonic acid and proteolytic enzymes are released from the cytoplasm. The released carbonic acid causes demineralization of bone tissue, and proteolytic enzymes destroy the organic matrix of the intercellular substance. Fragments of collagen fibers are phagocytosed by osteoclasts and destroyed intracellularly. Through these mechanisms, resorption (destruction) of bone tissue occurs, and therefore osteoclasts are usually localized in the recesses of bone tissue. After the destruction of bone tissue, due to the activity of osteoblasts moving out of the connective tissue of blood vessels, new bone tissue is built.

Intercellular substance bone tissue consists of a basic (amorphous) substance and fibers that contain calcium salts. The fibers consist of collagen and are folded into bundles, which can be arranged in parallel (ordered) or disorderly, on the basis of which the histological classification of bone tissue is based. The main substance of bone tissue, like other types of connective tissues, consists of glycosaminergic and proteoglycans.

Bone tissue contains less chondroitinsulfuric acids, but more citric acids and others, which form complexes with calcium salts. During the development of bone tissue, an organic matrix is first formed - the main substance and collagen fibers, and then calcium salts are deposited in them. They form crystals - hydroxyapatites, which are deposited both in the amorphous substance and in the fibers. Providing bone strength, calcium phosphate salts are also a depot of calcium and phosphorus in the body. Thus, bone tissue takes part in the mineral metabolism of the body.

When studying bone tissue, the concepts of “bone tissue” and “bone” should also be clearly distinguished.

Bone- this is the organ that is the main structural component which are bone tissue.

Classification of bone tissue

Hello my friends!

In this article we will look at what it is cartilage knee joint . Let's look at what cartilage is made of and what its function is. As you understand, in all joints of our body the cartilage tissue is the same, and everything described below also applies to other joints.

The ends of our bones in the knee joint are covered with cartilage; between them lie two menisci - these are also cartilages, but only slightly different in composition. Read about menisci in the article "". I will only say that cartilages and menisci differ in the type of cartilage tissue: bone cartilage is hyaline cartilage, and the menisci – fibrocartilage. This is what we will look at now.

The thickness of the cartilage covering the ends of the bone is on average 5-6 mm, it consists of several layers. Cartilage is dense and smooth, which allows bones to easily slide against each other during flexion and extension movements. Possessing elasticity, cartilage acts as a shock absorber during movements.

In a healthy joint, depending on its size, fluid is from 0.1 to 4 ml, the distance between cartilages (articular space) is from 1.5 to 8 mm, acid-base balance is 7.2-7.4, water is 95% , protein 3%. The composition of cartilage is similar to blood serum: 200-400 leukocytes per 1 ml, of which 75% are lymphocytes.

Cartilage is one of the types of connective tissue in our body. The main difference between cartilage tissue and others is the absence of nerves and blood vessels that directly feed this tissue. The blood vessels would not be able to withstand the stress and constant pressure, and the presence of nerves there would cause pain with every movement.

Cartilage is designed to reduce friction where bones connect. Cover both heads of the bone and the inside of the patella (kneecap). Constantly washed by synovial fluid, they ideally reduce friction in the joints to zero.

Cartilage does not have access to blood vessels and nutrition, respectively, and if there is no nutrition, then there is no growth or repair. But cartilage also consists of living cells and they also need nutrition. They receive nutrition from the same synovial fluid.

The meniscus cartilage is riddled with fibers, which is why it is called fibrocartilage and is denser and harder in structure than hyaline, therefore it has greater tensile strength and can withstand pressure.

Cartilage differs in its fiber ratio: . All this gives the cartilage not so much hardness as elasticity. Working like a sponge under load, cartilage and menisci are compressed, unclenched, flattened, stretched as you wish. They constantly absorb a new portion of liquid and give away the old one, forcing it to constantly circulate; at the same time, the liquid is enriched with nutrients and again carries them to the cartilage. We'll talk about synovial fluid later.

Main components of cartilage

Articular cartilage - This is a complex fabric in its structure. Let's look at the main components of this fabric. make up almost half of the intercellular space in articular cartilage. Collagen in its structure consists of very large molecules intertwined in triple helices. This structure of collagen fibers allows cartilage to resist any type of deformation. Collagen gives tissue elasticity. give elasticity, the ability to return to its original state.

The second element of cartilage that is of great importance is water, which is found in large quantities in the intercellular space. Water is a unique natural element; it is not subject to any deformation; it can neither be stretched nor compressed. This adds rigidity and elasticity to the cartilage tissue. In addition, the more water, the better and more functional the interarticular fluid. It spreads and circulates easily. With a lack of water, the joint fluid becomes more viscous, less fluid and, of course, performs its role in providing nutrition to the cartilage worse. !

Glycosamines– substances produced by the cartilage tissue of the joints are also part of the synovial fluid. By its structure, glucosamine is a polysaccharide and serves as an important component of cartilage.

Glucosamine is a precursor of glycosaminoglycans (the main component of articular cartilage), so it is believed that its additional external use can promote the restoration of cartilage tissue.

In our body, glucosamine binds cells and is part of cell membranes and proteins, making fabrics stronger and more resistant to stretching. Thus, glucosamine supports and strengthens our joints and ligaments. With a decrease in the amount of glucosamines, the resistance of cartilage tissue to stress also decreases, and the cartilage becomes more sensitive to damage.

The issues of restoration of cartilage tissue and the production of necessary compounds and substances are dealt with chondrocytes.

Chondrocytes, by their nature, do not differ from other cells in terms of development and regeneration, their metabolic rate is quite high. But the problem is that there are very few of these same chondrocytes. In articular cartilage, the number of chondrocytes is only 2-3% of the mass of the cartilage. Therefore, the restoration of cartilage tissue is so limited.

So, nutrition of cartilage is difficult, renewal of cartilage tissue is also a very long-term process, and restoration is even more problematic. What to do?

Considering all of the above, we come to the conclusion that in order for the cartilage of the knee joint to recover, it is necessary to achieve a high number and activity of chondrocyte cells. And our task is to provide them with adequate nutrition, which they can only receive through synovial fluid. But, even if the nutrition is the richest, it will not achieve its goal without moving the joint. That's why, If you move more, your recovery will be better!

With prolonged immobilization of a joint or the entire leg (plaster, splints, etc.), not only the muscles decrease and atrophy; It has been established that cartilage tissue also decreases, since it does not receive enough nutrition without movement. I will repeat myself for the hundredth time, but this is yet another proof of the need for constant movement. Man is created by nature in such a way that he must constantly run for food and run away from the mammoth, like other animals. Excuse me if I offend some of the “Crowns of Nature” by this. To scale evolutionary development, we have come too far for the body to behave differently; it has not yet adapted to other conditions of existence. And if the body feels that something in its composition is not needed or does not work well, it gets rid of it. Why feed something that is not beneficial? They stopped walking with their legs - their legs atrophied, the bodybuilder stopped pumping (using all his muscle mass) - he immediately deflated. Well, I got distracted.

In other articles, we will, of course, touch on issues (surgical methods and conservative ones), their nutrition and movement. This is what I, with my cartilage injury, am trying to implement. I'll tell you too.

In the meantime, my instructions: , COMPLETE VARIED NUTRITION,.

You can start right now.

All the best, don't get sick!

Many human organs have cartilage tissue in their structure, which performs a number of functions essential functions. This special type of connective tissue has a different structure depending on its location in the body, and this explains its different purposes.

The structure and functions of cartilage tissue are closely interrelated, each type plays a specific role.

Cartilage tissue under a microscope

Like any tissue in the body, cartilage contains two main components. This is the main intercellular substance, or matrix, and the cells themselves. The structural features of human cartilage tissue are that the mass fraction of the matrix is much greater than the total cellular weight. This means that during histological examination (examination of a tissue sample under a microscope), cartilage cells occupy little space, and the main area of the field of view is the intercellular substance. In addition, despite the high density and hardness of cartilage tissue, the matrix contains up to 80% water.

The structure of the intercellular substance of cartilage

The matrix has a heterogeneous structure and is divided into two components: the main, or amorphous, substance, with a mass fraction of 60%, and chondrin fibers, or fibrils, occupying 40% of the total weight of the matrix. These fibers are similar in structure to the collagen formations that make up, for example, human skin. But they differ from it in the diffuse, disordered arrangement of fibrils. Many cartilaginous formations have a kind of capsule called perichondrium. It plays a leading role in the restoration (regeneration) of cartilage.

Composition of cartilage

Cartilage tissue chemical composition is represented by various protein compounds, mucopolysaccharides, glycosaminoglycans, complexes of hyaluronic acid with proteins and glycosaminoglycans. These substances are the basis of cartilage tissue, the reason for its high density and strength. But at the same time, they ensure the penetration into it of various compounds and nutrients necessary for metabolism and cartilage regeneration. With age, the production and content of hyaluronic acid and glycosaminoglycans decreases, as a result, degenerative-dystrophic changes begin in the cartilage tissue. To slow down the progression of this process, replacement therapy is necessary, which ensures the normal functioning of cartilage tissue.

Cellular composition of cartilage

The structure of human cartilage tissue is such that cartilage cells, or chondrocytes, do not have a clear and ordered structure. Their localization in the intercellular substance is more reminiscent of single islands, consisting of one or several cellular units. Chondrocytes can vary in age, and are divided into young and undifferentiated cells (chondroblasts), and fully mature ones, called chondrocytes.

Chondroblasts are produced by the perichondrium and, gradually moving into the deeper layers of cartilage tissue, differentiate and mature. At the beginning of their development, they are not located in groups, but singly, have a round or oval shape and have a huge nucleus compared to the cytoplasm. Already at the initial stage of their existence, chondroblasts undergo active metabolism aimed at producing components of the intercellular substance. New proteins, glycosaminoglycans, and proteoglycans are formed, which then diffusely penetrate into the matrix.

Hyaline and elastic cartilage

The most important distinguishing feature chondroblasts, located immediately under the perichondrium, lies in their ability to divide and form their own kind. This feature is being actively studied by scientists, as it provides enormous opportunities for implementation. the newest way treatment of joint pathologies. By accelerating and regulating the division of chondroblasts, it is possible to completely restore cartilage tissue damaged by disease or injury.

Adult differentiated cartilage cells, or chondrocytes, are localized in the deep layers of cartilage. They are located in groups of 2-8 cells, and are called “isogenic groups”. The structure of chondrocytes is different from that of chondroblasts; they have a small nucleus and massive cytoplasm, and no longer know how to divide and form other chondrocytes. Their metabolic activity is also much reduced. They are capable of supporting metabolic processes in the cartilage tissue matrix only at a very moderate level.

Arrangement of elements in cartilage

Histological examination shows that the isogenic group is located in the cartilaginous lacuna and is surrounded by a capsule of interwoven collagen fibers. The chondrocytes in it are close to each other, separated only by protein molecules, and can have a variety of shapes: triangular, oval, round.

In diseases of cartilage tissue appears new look cells: chondroclasts. They are much larger than chondroblasts and chondrocytes, as they are multinucleated. These cells are not involved in either metabolism or cartilage regeneration. They are destroyers and “devourers” of normal cells and provide destruction and lysis of cartilage tissue during inflammatory or dystrophic processes in it.

Types of cartilage tissue

The intercellular substance of cartilage can have a different structure, depending on the type and location of the fibers. Therefore, there are 3 types of cartilage:

Hyaline, or glassy.
Elastic or mesh.
Fibrous or connective tissue.

Types of cartilage

Each type is characterized by a certain degree of density, hardness and elasticity, as well as localization in the body. Hyaline cartilaginous tissue lines the articular surfaces of bones, connects the ribs to the sternum, and is found in the trachea, bronchi, and larynx. Elastic cartilage is component small and medium bronchi, larynx, and human auricles are made from it. Connective cartilaginous tissue, or fibrous tissue, is so called because it connects ligaments or tendons of muscles with hyaline cartilage (for example, at the points of attachment of tendons to the bodies or processes of the vertebrae).

Blood supply and innervation of cartilage tissue

The structure of cartilage is very dense; it is not penetrated by even the smallest blood vessels (capillaries). All nutrients and oxygen necessary for the functioning of cartilage tissue enter it from the outside. In a diffuse manner, they penetrate from nearby blood vessels, from the perichondrium or bone tissue, and from the synovial fluid. Decay products are also removed diffusely and are removed from the cartilage through venous vessels.

Young and mature cartilage

Nerve fibers penetrate into the superficial layers of cartilage from the perichondrium only in separate single branches. This explains the fact that nerve impulses from cartilage tissue do not arrive during diseases, and pain syndrome appears during the reaction of bone structures, when the cartilage is practically destroyed.

Functions of cartilage tissue

The main function of cartilage tissue is musculoskeletal, which is to ensure strong connections between various parts of the skeleton and a wide variety of movements. Thus, hyaline cartilage, which is the most important structural part of the joints and lines the bone surfaces, makes possible the entire range of human movements. Thanks to its physiological sliding, they occur smoothly, comfortably and painlessly, with appropriate amplitude.

Cartilage of the knee joint

Other connections between bones that do not involve active movements in them are also made using durable cartilage tissue, in particular the hyaline type. These may be low-moving bone fusions that perform a supporting function. For example, in the places where the ribs meet the sternum.

The functions of connective cartilage tissue are explained by its localization and consist in ensuring the mobility of various parts of the skeleton. It makes possible a strong and elastic connection of muscle tendons with bone surfaces covered with hyaline cartilage.

Other functions of human cartilage tissue are also important, as they form the appearance, voice, and ensure normal breathing. First of all, this applies to the cartilage tissue that forms the basis of the ears and the tip of the nose. The cartilage that makes up the trachea and bronchi makes them mobile and functional, and the cartilaginous structures of the larynx are involved in the formation of the individual timbre of the human voice.