Cartilaginous tissue: functions and features of the structure

It's no secret that athletes even in good physical condition and at a comparatively early age often give up training because of injuries. A large proportion of their problems are ligaments. The weakest part is cartilaginous tissue. The functions of damaged joints, it turns out, can be restored if timely attention is paid to the problem and to create suitable conditions for the treatment and regeneration of their cells.

Fabrics in the human body

The human body is a complex and flexible system capable of self-regulation. It consists of cells different in structure and function. They are the main metabolism. Together with non-cellular structures they are combined into tissues: epithelial, muscular, nervous, connective.

Epithelial cells form the basis of the skin. They lining the internal cavities (abdominal, thoracic, upper respiratory tract, intestinal tract). Muscular tissue enables a person to move. It also ensures the movement of internal environments in all organs and systems. The musculature is divided into the following types: smooth (walls of the cavity organs and vessels), cardiac, skeletal (transversely striated). The nerve tissue provides the transfer of impulses from the brain. Some cells are able to grow and multiply, some of them are capable of regeneration.

The connective tissue is the internal environment of the body. It is different in structure, structure and properties. It consists of strong bones of the skeleton, subcutaneous fatty tissue, liquid media: blood and lymph. It also includes cartilaginous tissue. Its functions are forming, amortization, supporting and supporting. All of them play an important role and are necessary in a complex system of the body.

Cartilage tissue: structure and function

Its characteristic feature is looseness in the arrangement of cells. Considering them separately, you can see how clearly they are separated from each other. The intercellular substance - matrix - acts as a ligament between them. And in different types of cartilage it is formed besides the main amorphous substance by various fibers (elastic and collagen). Although they have a common protein origin, but differ in properties and, depending on it, perform various functions.

All bones of the body were formed from cartilage. But as they grew, the intercellular substance was filled with crystals of salts (mainly calcium). As a result, the bones gained strength and became part of the skeleton. Cartilages also perform supporting functions. In the spine, between segments, they perceive constant loads (static and dynamic). Ears, nose, trachea, bronchi - in these areas tissue plays a more formative role.

Growth and nutrition of the cartilage is through the perichondrium. It is in the tissue is an obligatory part, except for the joints. In them, between the rubbing surfaces there is a synovial fluid. It washes, lubricates and nourishes them, diverts the exchange products.

Structure

In the cartilage there are few cells capable of division, and a lot of space around them, filled with protein substances of different properties. Because of this peculiarity, the regeneration processes are often more in the matrix.

There are two types of tissue cells: gonrotsity (mature) and chondroblasts (young). They differ in size, location and method of location. Chondrocytes have a rounded shape, and they are larger. They are arranged in pairs or in groups of up to 10 cells. Chondroblasts are usually smaller and located in the tissue along the periphery or singly.

In the cytoplasm of cells under the shell, water accumulates, there are inclusions of glycogen. Oxygen and nutrients enter the cells diffusely. There is a synthesis of collagen and elastin. They are necessary for the formation of intercellular substance. From its specifics, it depends on what type it will be cartilaginous tissue. Features of the structure and function of the larynx differ from the intervertebral discs, including the content of collagen. In the auricles, in the cartilage of the nose, the intercellular substance consists of 30% elastin.

Kinds

How is the cartilaginous tissue classified? Its functions depend on the predominance of specific fibers in the matrix. If there is more elastin in the intercellular substance, the cartilaginous tissue will be more plastic. It is almost as strong, but the fiber bundles are thinner in it. They well withstand loads not only on compression, but also on stretching, capable of deformations without critical consequences. Such cartilage is called elastic. Their tissues form the larynx, ears, nose.

If there is a large amount of collagen in the matrix around the cells with a complex structure of polypeptide chains, this cartilage is called hyaline. It often covers the inner surfaces of the joints. The greatest amount of collagen is concentrated in the surface zone. It plays the role of a skeleton. The fiber bundles in it resemble in structure the three-dimensional intertwined networks of a spiral shape.

There is one more group: fibrous, or fibrous, cartilage. They, like hyaline, contain a large amount of collagen in the intercellular substance, but it has a special structure. The bundles of their fibers do not have a complex interlacing and are located along the axis of the greatest loads. They are thicker, have a special compressive strength, are poorly restored by deformation. Intervertebral discs, joints of tendons with bones are formed from such tissue.

Functions

Due to the special biomechanical properties, the cartilage tissue is ideally suited for binding the components of the musculoskeletal system. It is able to accept the forces of compression and stretching during movements, redistribute them evenly to the load, to some extent absorb or dissipate.

Cartilages form abrasion-resistant surfaces. Together with the synovial fluid, such joints with permissible loads can for a long time normally perform their functions.

Tendons are not cartilaginous tissue. Their functions are also to bind the musculoskeletal system into a common system . They also consist of bundles of collagen fibers, but their structure and origin are different. Cartilage of the nose, respiratory organs, auricles, in addition to performing the forming and supporting functions are the place of attachment of soft tissues. But unlike the tendons, the muscles next to them do not have this load.

Special Properties

There are very few vessels in the elastic cartilages. And this is understandable, because a strong dynamic load can damage them. How does the cartilaginous connective tissue feed? These functions take on the intercellular substance. In the hyaline cartilage there are no vessels at all. Their rubbing surfaces are quite tough and dense. They are fed by the synovial fluid of the joint.

In the matrix, water moves freely. It contains all the necessary substances for metabolic processes. Proteoglycanic components in the cartilage perfectly bind the water. It as an incompressible substance provides rigidity and additional depreciation. Under loads, water takes on an influence, spreads throughout the intercellular space and smoothly removes stress, preventing irreversible critical deformations.

Development

In the adult body, up to 2% of the mass is in the cartilaginous tissue. Where is it concentrated and what functions does it perform? Cartilage and bone tissue in the embryonic period is not differentiated. There are no bones in the embryos. They develop from cartilaginous tissue and are formed at the time of birth. But some of it does not ossify. It forms ears, nose, larynx, bronchi. It is also present in the joints of the hands and feet, the joints of the pubic bones, intervertebral discs, knee menisci.

The development of cartilage occurs in several stages. First the mesenchyme cells are saturated with water, rounded, they lose their shoots and begin to produce substances for the matrix. After this, they differentiate into chondrocytes and chondroblasts. The former turn out to be tightly surrounded by the intercellular substance. In this state, they can be divided a limited number of times. After such processes an isogenic group is formed. Cells that remain on the surface of the tissue become chondroblasts. In the process of production of matrix substances, the final differentiation takes place, a structure is formed with a distinct division into a thin border and the basis of the tissue.

Age changes

The functions of the cartilage tissue of a person do not change in the course of life. However, over time, you can see signs of aging: muscles and tendons of the joints are weakened, flexibility is lost, pains are aggravated by weather change or unaccustomed exercise. Such a process is considered a physiological norm. By the age of 30-40 years, the symptoms of changes can begin to cause inconvenience to a greater or lesser extent. Aging of the articular cartilage tissue is due to the loss of its elasticity. The elasticity of the fibers is lost. The fabric dries up, loosens up.

Cracks appear on the smooth surface, it becomes rough. Smoothness and ease of sliding is no longer possible. Damaged edges expand, deposits form in them, osteophytes form in the tissue. Elastic cartilages age with accumulation in the intercellular substance of calcium, but this is almost not reflected in their functions (nose, ears).

Dysfunction of cartilage and bone tissue

When and how can this happen? To a large extent, this depends on the function of the cartilaginous tissue. In intervertebral discs, the main function of which is stabilizing and supporting, most often the disruption of the work occurs with the development of dystrophic or degenerative processes. The situation can lead to displacements, which, in turn, entails squeezing the surrounding tissues. An edema, an infringement of nerves, squeezing of vessels is inevitable.

To restore stability, the body tries to fight the problem. The vertebra in the place of deformation "adapts" to the situation, grows in the form of peculiar bone outgrowths (mustache). It also does not benefit the surrounding tissues: again swelling, pinching, squeezing. This problem is complex. Disturbances in the functioning of the osteochondral cartilage apparatus are usually called osteochondrosis.

Long-term restriction of motion (gypsum during injuries) also affects cartilage negatively. If, under excessive loads, elastic fibers degenerate into coarse fibrous bundles, then at low activity the cartilage does not normally feed. The synovial fluid is poorly mixed, the chondrocytes do not receive enough nutrients, as a result, the required amount of collagen and elastin for the matrix is not produced.

The conclusion suggests itself: for normal operation of the joints, the cartilage should receive a sufficient load for tension and compression. To ensure this, you need to exercise, lead a healthy and active lifestyle.