Articulation types. Joints, their structure and function

Joints can be classified according to the following principles:
1) by the number of articular surfaces,
2) according to the shape of the articular surfaces and
3) by function.

According to the number of joints surfaces are:
1. Simple joint (art. simplex) having only 2 articular surfaces, such as interphalangeal joints.
2. Complex joint (art. composite) having more than two articular surfaces, such as the elbow joint. A complex joint consists of several simple joints in which movements can be performed separately. The presence of several joints in a complex joint determines the commonality of their ligaments.
3. Complex joint (art. complexa) containing intra-articular cartilage, which divides the joint into two chambers (two-chamber joint). The division into chambers occurs either completely if the intra-articular cartilage is disc-shaped (for example, in the temporomandibular joint), or incompletely if the cartilage takes the form of a semilunar meniscus (for example, in the knee joint).
4. Combined joint represents a combination of several joints isolated from each other, located separately from each other, but functioning together. Such, for example, are both temporomandibular joints, the proximal and distal radioulnar joints, etc.
Since the combined joint is a functional combination of two or more anatomically separate joints, in this way it differs from the complex and complex joints, each of which, being anatomically unified, is composed of functionally different compounds.

Form and function classification is carried out as follows.
Joint function determined by the number of axes around which movements are made. The number of axes around which movements occur in a given joint depends on the shape of its articular surfaces. So, for example, the cylindrical shape of the joint allows movement only around one axis of rotation.
In this case, the direction of this axis will coincide with the axis of the cylinder itself: if the cylindrical head is vertical, then the movement is performed around the vertical axis (cylindrical joint); if the cylindrical head lies horizontally, then the movement will take place around one of the horizontal axes coinciding with the axis of the head, for example, the frontal (block joint).

In contrast to this spherical shape and the head makes it possible to rotate around a plurality of axes coinciding with the radii of the ball (spherical joint).
Therefore, between the number of axles and form articular surfaces there is a complete correspondence: the shape of the articular surfaces determines the nature of the movements of the joint and, conversely, the nature of the movements of a given articulation determines its shape (P. F. Lesgaft).

Here we see the manifestation of the dialectical principle of the unity of form and function.
Based on this principle, we can outline the following unified anatomical and physiological classification of joints.

The figure shows:
Uniaxial joints: 1a - block-shaped talocrural joint (articulario talocruralis ginglymus)
1b - block-shaped interphalangeal joint of the hand (articulatio interpalangea manus ginglymus);
1c - cylindrical shoulder-radial joint of the elbow joint, articulatio radioulnaris proximalis trochoidea.

Biaxial joints: 2a - elliptical wrist joint, articulatio radiocarpea ellipsoidea;
2b - condylar knee joint (articulatio genus -articulatio condylaris);
2c - saddle carpometacarpal joint, (articulatio carpometacarpea pollicis - articulatio sellaris).

Triaxial joints: 3a - spherical shoulder joint (articulatio humeri - articulatio spheroidea);
3b - cup-shaped hip joint (articulatio coxae - articulatio cotylica);
3c - flat sacroiliac joint (articulatio sacroiliaca - articulatio plana).

I. Uniaxial joints

1. Cylindrical joint, art. trochoidea. The cylindrical articular surface, the axis of which is located vertically, parallel to the long axis of the articulating bones or the vertical axis of the body, provides movement around one vertical axis - rotation, rotatio; such a joint is also called rotational.

2. Block joint, ginglymus(example - interphalangeal joints of the fingers). Its block-shaped articular surface is a transversely lying cylinder, the long axis of which lies transversely, in the frontal plane, perpendicular to the long axis of the articulating bones; therefore, movements in the trochlear joint are performed around this frontal axis (flexion and extension). Guiding groove and scallop on the articulating surfaces eliminate the possibility of lateral slip and promote movement around one axis.
If the guide groove block is located not perpendicular to the axis of the latter, but at a certain angle to it, then when it is continued, a helical line is obtained. Such a block-shaped joint is considered as a helical joint (an example is the glenohumeral joint). The movement in the helical joint is the same as in the purely trochlear joint.
According to the rules of location ligamentous apparatus, in the cylindrical joint, the guide ligaments will be located perpendicular to the vertical axis of rotation, in the trochlear joint - perpendicular to the frontal axis and on its sides. This arrangement of ligaments holds the bones in their position without interfering with movement.

II. Biaxial joints

1. Elliptical joint, articulatio ellipsoidea(example - wrist joint). The articular surfaces represent segments of an ellipse: one of them is convex, oval in shape with unequal curvature in two directions, the other is respectively concave. They provide movement around 2 horizontal axes perpendicular to each other: around the frontal - flexion and extension, and around the sagittal - abduction and adduction.
Bundles in elliptical joints located perpendicular to the axes of rotation, at their ends.

2. condylar joint, articulatio condylaris(example - knee joint).
condylar joint has a convex articular head in the form of a protruding rounded process, close in shape to an ellipse, called the condyle, condylus, which is where the name of the joint comes from. The condyle corresponds to a depression on the articular surface of another bone, although the difference in size between them can be significant.

condylar joint can be considered as a kind of elliptical, representing a transitional form from a block-shaped joint to an elliptical one. Therefore, its main axis of rotation will be frontal.

From blocky condylar joint differs in that there is a large difference in size and shape between the articulating surfaces. As a result, in contrast to the block-like joint, movements around two axes are possible in the condylar joint.

From elliptical joint it differs in the number of articular heads. Condylar joints always have two condyles, located more or less sagittally, which are either in the same capsule (for example, the two condyles of the femur involved in the knee joint), or located in different articular capsules, as in the atlantooccipital articulation.

Insofar as in the condylar joint of the head do not have the correct ellipse configuration, the second axis will not necessarily be horizontal, as is typical for a typical elliptical joint; it can also be vertical (knee joint).

If a condyles are located in different articular capsules, then such a condylar joint is close in function to an elliptical joint (atlantooccipital articulation). If the condyles are close together and are in the same capsule, as, for example, in the knee joint, then the articular head as a whole resembles a recumbent cylinder (block), dissected in the middle (the space between the condyles). In this case, the condylar joint will be closer in function to the block joint.

3. saddle joint, art. sellaris(an example is the carpometacarpal joint of the first finger).
This joint is formed by 2 saddle articular surfaces, sitting "on top" of each other, of which one moves along and across the other. Due to this, movements are made in it around two mutually perpendicular axes: frontal (flexion and extension) and sagittal (abduction and adduction).
In biaxial joints it is also possible to move from one axis to another, i.e., circular motion (circumductio).

III. Multiaxial joints

1. spherical. ball joint, art. spheroidea(example - shoulder joint). One of the articular surfaces forms a convex, spherical head, the other - a correspondingly concave articular cavity. Theoretically, the movement can be performed around many axes corresponding to the radii of the ball, but in practice, three main axes are usually distinguished among them, perpendicular to each other and intersecting in the center of the head:
1) transverse (frontal), around which flexion occurs, flexio, when the moving part forms an angle with the frontal plane, open anteriorly, and extension, extensio, when the angle is open backwards;
2) anteroposterior (sagittal), around which abduction, abductio, and adduction, adductio, are performed;
3) vertical, around which rotation occurs, rotatio, inward, pronatio, and outward, supinatio.
When moving from one axis to another, a circular motion, circumductio, is obtained.

ball joint- the most free of all joints. Since the amount of movement depends on the difference in the areas of the articular surfaces, the articular fossa in such a joint is small compared to the size of the head. There are few auxiliary ligaments in typical spherical joints, which determines the freedom of their movements.

Variety spherical joint- bowl joint, art. cotylica (cotyle, Greek - bowl). Its articular cavity is deep and covers most of the head. As a result, movements in such a joint are less free than in a typical spherical joint; we have a sample of the bowl-shaped joint in the hip joint, where such a device contributes to greater stability of the joint.

2. flat joints, art. plana(example - artt. intervertebrales), have almost flat articular surfaces. They can be considered as surfaces of a ball with a very large radius, therefore, movements in them are performed around all three axes, but the range of movements due to the insignificant difference in the areas of the articular surfaces is small.
Bundles in multi-axle joints located on all sides of the joint.

Tight joints - amphiarthrosis

Under this name, a group of joints with different the shape of the articular surfaces, but similar in other ways: they have a short, tightly stretched joint capsule and a very strong, non-stretching auxiliary apparatus, in particular short reinforcing ligaments (an example is the sacroiliac joint).

As a result, the articular surfaces are in close contact with each other. friend which severely restricts movement. Such inactive joints are called tight joints - amphiarthrosis (BNA). Tight joints soften shocks and tremors between bones.

These joints also include flat joints, art. plana, in which, as noted, the flat articular surfaces are equal in area. In tight joints, movements are of a sliding nature and are extremely insignificant.

Video lesson: Classification of joints. Range of motion in the joints

Joints unite the bones of the skeleton into a single whole. More than 180 different joints help a person move. Together with bones and ligaments, they are referred to as the passive part of the motor apparatus.

Joints can be compared to hinges, the task of which is to ensure smooth sliding of bones relative to each other. In their absence, the bones will simply rub against each other, gradually breaking down, which is a very painful and dangerous process. In the human body, the joints play a triple role: they help maintain the position of the body, participate in the movement of body parts relative to each other, and are the organs of locomotion (movement) of the body in space.

Each joint has various elements that facilitate the mobility of some parts of the skeleton and ensure strong conjugation of others. In addition, there are non-osseous tissues that protect the joint and soften interosseous friction. The structure of the joint is very interesting.

The main elements of the joint:

joint cavity;

Epiphyses of the bones that form the joint. The epiphysis is a rounded, often expanded, terminal section of a tubular bone that forms a joint with an adjacent bone by articulating their articular surfaces. One of the articular surfaces is usually convex (located on the articular head), and the other is concave (formed by the articular fossa)

Cartilage is the tissue that covers the ends of bones and cushions their friction.

The synovial layer is a kind of bag that lines the inner surface of the joint and secretes synovium, a fluid that nourishes and lubricates the cartilage, since the joints do not have blood vessels.

The joint capsule is a sleeve-like, fibrous layer enveloping the joint. It gives the bones stability and prevents their excessive displacement.

The menisci are two hard cartilages shaped like crescents. They increase the area of ​​contact between the surfaces of two bones, as, for example, the knee joint.

Ligaments are fibrous formations that strengthen interosseous joints and limit the amplitude of bone movement. They are located on the outside of the joint capsule, but in some joints they are located inside for better strength, such as round ligaments in the hip joint.

The joint is an amazing natural mechanism of movable conjugation of bones, where the ends of the bones are connected in the articular bag. bag outside is a fairly strong fibrous tissue - it is a dense protective capsule with ligaments that help control and hold the joint, preventing displacement. From the inside, the articular bag is synovial membrane.

This membrane produces synovial fluid - lubrication of the joint, viscoelastic consistency, which even in a healthy person is not so much, but it occupies the entire joint cavity and is able to perform important functions:

1. It is a natural lubricant that gives the joint freedom and ease of movement.

2. It reduces the friction of the bones in the joint, and thus protects the cartilage from abrasion and wear.

3. Acts as shock absorber and shock absorber.

4. Works as a filter, providing and maintaining cartilage nutrition, while protecting it and the synovial membrane from inflammatory factors.

synovial fluid A healthy joint has all of these properties, largely due to hyaluronic acid found in the synovial fluid, as well as in cartilage tissue. It is this substance that helps your joints to fully perform their functions and allows you to lead an active life.

If the joint is inflamed or diseased, then more synovial fluid is produced in the synovial membrane of the joint capsule, which also contains inflammatory agents that increase swelling, swelling, and pain. Biological inflammatory agents destroy the internal structures of the joint.

The ends of the joints of the bones are covered with an elastic thin layer of smooth substance - hyaline cartilage. Articular cartilage does not contain blood vessels or nerve endings. The cartilage, as has been said, receives its nourishment from the synovial fluid and from the bony structure beneath the cartilage itself, the subchondral bone.

Cartilage It mainly acts as a shock absorber - it reduces pressure on the mating surfaces of the bones and ensures smooth sliding of the bones relative to each other.

Functions of cartilage

1. Reduce friction between joint surfaces

2. Absorb shocks transmitted to the bone during movement

Cartilage is made up of special cartilage cells - chondrocytes and intercellular substance matrix. The matrix consists of loosely located connective tissue fibers - the main substance of cartilage, which is formed by special compounds - glycosaminoglycans.
Namely, connected by protein bonds, glycosaminoglycans that form larger cartilage structures - proteoglycans - are the best natural shock absorbers, since they have the ability to restore their original shape after mechanical compression.

In view of the special structure, cartilage resembles a sponge - absorbing fluid in a calm state, it releases it into the articular cavity under load and thus, as it were, additionally "lubricates" the joint.

Such a common disease as arthrosis upsets the balance between the formation of new and the destruction of the old building material that forms cartilage. Cartilage (the structure of the joint) changes from strong and elastic to dry, thin, dull and rough. The underlying bone thickens, becomes more uneven, and begins to grow away from the cartilage. This contributes to the restriction of movement and causes deformation of the joints. There is a seal of the joint capsule, as well as its inflammation. The inflammatory fluid fills the joint and begins to stretch the capsule and joint ligaments. This creates a painful feeling of stiffness. Visually, you can observe an increase in the joint in volume. Pain, and subsequently deformation of the surfaces of the joints in arthrosis, leads to tight joint mobility.

Joints are distinguished by the number of articular surfaces:

• simple joint (lat. articulatio simplex) - has two articular surfaces, for example, the interphalangeal joint of the thumb;
• complex joint (lat. articulatio composita) - has more than two articular surfaces, for example, the elbow joint;
• complex joint (lat. articulatio complexa) - contains intra-articular cartilage (meniscus or disc), dividing the joint into two chambers, for example, the knee joint;
• combined joint - a combination of several isolated joints located separately from each other, for example, the temporomandibular joint.

In shape, the articular surfaces of bones are compared with geometric figures and, accordingly, joints are distinguished: spherical, ellipsoid, block-shaped, saddle-shaped, cylindrical, etc.

Joints with movement

. shoulder joint: the articulation that provides the greatest range of motion of the human body is the articulation of the humerus with the scapula using the glenoid cavity of the scapula.

. elbow joint: connection of the humerus, ulna and radius bones, allowing you to make a rotational movement of the elbow.

. Knee-joint: a complex joint that provides flexion and extension of the leg and rotational movements. The femur and tibia are articulated at the knee joint - the two longest and strongest bones, which, together with the patella, located in one of the tendons of the quadriceps muscle, are pressed by almost the entire weight of the skeleton.

. hip joint: connection of the femur with the bones of the pelvis.

. wrist joint: formed by several joints located between numerous small flat bones connected by strong ligaments.

. Ankle joint: the role of ligaments is very important in it, which not only provide movement of the lower leg and foot, but also support the concavity of the foot.

There are the following main types of movements in the joints:

• movement around the frontal axis - flexion and extension;
• movements around the sagittal axis - adduction and abduction of movement around the vertical axis, that is, rotation: inwards (pronation) and outwards (supination).

The human hand contains: 27 bones, 29 joints, 123 ligaments, 48 ​​nerves and 30 named arteries. Throughout life, we move our fingers millions of times. The movement of the hand and fingers is provided by 34 muscles, only when moving the thumb, 9 different muscles are involved.

shoulder joint

It is the most mobile in humans and is formed by the head of the humerus and the glenoid cavity of the scapula.

The articular surface of the scapula is surrounded by a ring of fibrous cartilage - the so-called articular lip. The tendon of the long head of the biceps brachii passes through the joint cavity. The shoulder joint is strengthened by a powerful coraco-shoulder ligament and surrounding muscles - deltoid, subscapular, supra- and infraspinatus, large and small round. The pectoralis major and latissimus dorsi muscles also take part in the movements of the shoulder.

The synovial membrane of the thin articular capsule forms 2 extra-articular torsion - the tendons of the biceps of the shoulder and the subscapularis. The anterior and posterior arteries enveloping the humerus and the thoracoacromial artery take part in the blood supply of this joint, the venous outflow is carried out into the axillary vein. The outflow of lymph occurs in the lymph nodes of the armpit. The shoulder joint is innervated by branches of the axillary nerve.

In the shoulder joint, movements around 3 axes are possible. Flexion is limited by the acromial and coracoid processes of the scapula, as well as the coracobrachial ligament, extension by the acromion, coracobrachial ligament, and joint capsule. Abduction in the joint is possible up to 90°, and with the participation of the girdle of the upper extremities (with the inclusion of the sternoclavicular joint) - up to 180°. The abduction stops at the moment the large tubercle of the humerus abuts against the coracoid-acromial ligament. The spherical shape of the articular surface allows a person to raise the arm, take it back, rotate the shoulder along with the forearm, the hand in and out. This variety of hand movements was a decisive step in the process of human evolution. The shoulder girdle and shoulder joint in most cases function as a single functional entity.

hip joint

It is the most powerful and heavily loaded joint in the human body and is formed by the acetabulum of the pelvic bone and the head of the femur. The hip joint is strengthened by the intra-articular ligament of the head of the femoral brush, as well as the transverse ligament acetabulum, covering the neck of the femur. Outside, a powerful ilio-femoral, pubic-femoral and ischio-femoral ligaments are woven into the capsule.

The blood supply to this joint is carried out through the arteries that envelop the femur, branches of the obturator and (inconsistently) branches of the superior perforating, gluteal and internal pudendal arteries. The outflow of blood occurs through the veins surrounding the femur, into the femoral vein and through the obturator veins into the iliac vein. Lymph drainage is carried out to the lymph nodes located around the external and internal iliac vessels. The hip joint is innervated by the femoral, obturator, sciatic, superior and inferior gluteal, and pudendal nerves.
The hip joint is a type of ball-and-socket joint. It allows movements around the frontal axis (flexion and extension), around the sagittal axis (abduction and adduction) and around the vertical axis (external and internal rotation).

This joint is under heavy load, so it is not surprising that its lesions occupy the first place in the general pathology of the articular apparatus.

Knee-joint

One of the largest and most complex human joints. It is made up of 3 bones: the femur, tibia, and fibula. Stability of the knee joint is provided by intra- and extra-articular ligaments. The extra-articular ligaments of the joint are the peroneal and tibial collateral ligaments, the oblique and arcuate popliteal ligaments, the patellar ligament, and the medial and lateral patella ligaments. The intraarticular ligaments include the anterior and posterior cruciate ligaments.

The joint has many auxiliary elements, such as menisci, intra-articular ligaments, synovial folds, synovial bags. Each knee joint has two menisci, one external and one internal. The menisci have the form of crescents and perform a shock-absorbing role. The auxiliary elements of this joint include synovial folds, which are formed by the synovial membrane of the capsule. The knee joint also has several synovial bags, some of which communicate with the joint cavity.

Everyone had to admire the performances of gymnasts and circus performers. People who can climb into small boxes and bend unnaturally are said to have gutta-percha joints. Of course, this is not so. The authors of The Oxford Handbook of Body Organs assure readers that "in such people the joints are phenomenally flexible" - in medicine this is called joint hypermobility syndrome.

The shape of the joint is a condylar joint. It allows movements around 2 axes: frontal and vertical (with a bent position in the joint). Flexion and extension occur around the frontal axis, and rotation occurs around the vertical axis.

The knee joint is very important for human movement. With each step, by bending, it allows the foot to step forward without hitting the ground. Otherwise, the leg would be brought forward by raising the hip.

According to the World Health Organization, every 7th inhabitant of the planet suffers from joint pain. Between the ages of 40 and 70, joint disease occurs in 50% of people and in 90% of people over 70 years of age.
According to www.rusmedserver.ru, meddoc.com.ua

Joint- the place where the bones of a person are connected. Joints are necessary for the mobility of bone joints, and they also provide mechanical support.

The joints are formed by the articular surfaces of the epiphyses of the bones, which are covered with hyaline cartilage, the articular cavity, which contains a small amount of synovial fluid, as well as the articular bag and synovial membrane. In addition, the knee joint contains menisci, which are cartilage formations that have a shock-absorbing effect.

The articular surfaces are coated with hyaline or fibrous articular cartilage, which is 0.2 to 0.5 mm thick. Smoothness is achieved through constant friction, while the cartilage acts as a shock absorber.

The articular capsule (joint bag) is covered with an outer fibrous membrane and an inner synovial membrane and has a connection with the connecting bones at the edges of the articular surfaces, while it seals the articular cavity, thereby protecting it from external influences. The outer layer of the joint capsule is much stronger than the inner one, as it consists of dense fibrous connective tissue, the fibers of which are arranged longitudinally. In some cases, the joint capsule is connected by ligaments. The inner layer of the joint capsule consists of the synovial membrane, the villi of which produce synovial fluid, which provides moisture to the joint, reduces friction and nourishes the joint. This part of the joint has the most nerves.

Joints surround the periarticular tissues, which include muscles, ligaments, tendons, blood vessels, and nerves.

Ligaments of joints consist of dense tissue, they are necessary to control the range of motion of the joints and are located on the outside of the joint capsule, with the exception of the knee and hip joints, where the connections are also inside, providing additional strength.

Blood supply to the joints occurs along the articular arterial network, which includes from 3 to 8 arteries. The innervation of the joints is provided by the spinal and sympathetic nerves. All elements of the joint have innervation, with the exception of hyaline cartilage.

Joints are classified functionally and structurally.

The structural classification of the joints divides the joints according to the type of bone connections, and the functional classification of the joints divides the joints according to the ways of motor functions.

The structural classification of the joints divides them according to the type of connective tissue.

There are three types of joints according to the structural classification:

• Fibrous joints- have a dense regular connective tissue rich in collagen fibers.
• cartilaginous joints- connections are formed by cartilage tissue.
• synovial joints- the bones in this type of joints have cavities and are connected by a dense irregular connective tissue that forms a joint capsule, which usually has additional ligaments.

Functional classification of joints divides joints into the following types:

• Synarthrosis joints- joints that are almost completely devoid of mobility. Most of the synarthrosis joints are fibrous joints. For example, they connect the bones of the skull.
• Amphiarthrosis joints- joints that provide moderate mobility of the skeleton. Such joints include, for example, intervertebral discs. These joints are cartilaginous joints.


• diarthritic joints- joints that provide free movement of joints. These joints include the shoulder joint, hip joint, elbow joint, and others. These joints have a synovial connection. At the same time, diarthrotic joints are divided into six subgroups depending on the type of movement: spherical joints, nut-shaped (cup-shaped) joints, block-shaped (hinge) joints, swivel joints, condylar joints, joints connecting by mutual reception.

Joints are also divided according to the number of axes of motion: monoaxial joints, biaxial joints and multiaxial joints. Joints are also divided into one, two and three degrees of freedom. Also, the joints are divided according to the type of articular surfaces: flat, convex and concave.

There is a division of joints according to their anatomical structure or biomechanical properties. In this case, the joints are divided into simple and complex, it all depends on the number of bones that are involved in the structure of the joint.

• simple joint- has two movable surfaces. Simple joints include the shoulder joint and the hip joint.
• compound joint A joint that has three or more movable surfaces. Such a joint can be attributed to the wrist joint.
• Composite joint- this joint has two or more movable surfaces, as well as an articular disc or meniscus. One such joint is the knee joint.

Anatomically, the joints are divided into the following groups:

• Hand joints
• Wrist joints
• Elbow joints
• Axillary joints
• Sternoclavicular joints
• Vertebral joints
• Temporomandibular joints
• sacroiliac joints
• Hip joints
• knee joints
• Foot joints

Joint diseases

Joint disease is called arthropathy. When a joint disorder is accompanied by inflammation of one or more joints, this is called arthritis. Moreover, when several joints are included in the inflammatory process, the disease is called polioarthritis, and when one joint becomes inflamed, this is called monoarthritis.

Arthritis is the leading cause of disability in people over 55 years of age. Arthritis comes in several forms, each with different causes. The most common form of arthritis is osteoarthritis or a degenerative joint disease that occurs as a result of joint injury, infection, or old age. Also, according to the studies, it became known that incorrect anatomical development is also the cause of the early development of osteoarthritis.

Other forms of arthritis such as rheumatoid arthritis t and psoriatic arthritis are the result of autoimmune diseases.

Septic arthritis caused by joint infection.

Gouty arthritis is caused by the deposition of uric acid crystals in the joint, which causes subsequent inflammation of the joint.

pseudogout characterized by the formation with deposition of diamond-shaped crystals of calcium pyrophosphate in the joint. This form of arthritis is less common.

There is also such a pathology as hypermobility joints. This disorder occurs most often in young women and is characterized by increased joint mobility as a result of sprained articular ligaments. In this case, the movement of the joint can fluctuate beyond its anatomical limits. This violation is associated with a structural change in collagen. It loses strength and becomes more elastic, which leads to its partial deformation. It is believed that this disorder is hereditary.

anatomus.ru

Types of human joints

They can be classified according to functionality:

A joint that does not allow movement is known as synarthrosis. Skull sutures and gomphos (connection of teeth to the skull) are examples of synarthroses. Connections between bones are called syndesmoses, between cartilage - synchordroses, bone tissue - synthostoses. Synarthroses are formed with the help of connective tissue.

Amphiarthrosis allows little movement of the connected bones. Examples of amphiarthrosis are the intervertebral discs and the pubic symphysis.

The third functional class is free-moving diarthrosis. They have the highest range of motion. Examples: elbows, knees, shoulders and wrists. Almost always these are synovial joints.

The joints of the human skeleton can also be classified according to their structure (according to the material of which they are composed):

Fibrous joints are made up of tough collagen fibers. These include the sutures of the skull and the joint that joins the ulna and radius bones of the forearm together.

Cartilaginous joints in humans are made up of a group of cartilages that connect bones together. Examples of such connections would be the joints between the ribs and costal cartilage, as well as between the intervertebral discs.

The most common type, the synovial joint, is a fluid-filled space between the ends of the bones being bonded. It is surrounded by a capsule of rigid dense connective tissue covered with a synovial membrane. The synovial membrane that makes up the capsule produces an oily synovial fluid whose function is to lubricate the joint, reducing friction and wear.

There are several classes of synovial joints, such as ellipsoid, trochlear, saddle and ball joint.

Ellipsoid joints connect smooth bones together and allow them to slide past each other in any direction.

Throat joints, such as the human elbow and knee, restrict movement in only one direction so that the angle between the bones can be increased or decreased. Limited movement in the trochlear joints provides more strength and strength to the bones, muscles and ligaments.

Saddle joints, such as those between the first metacarpal and the trapezium, allow the bones to rotate 360 ​​degrees.

The human shoulder and hip joints are the only ball-and-socket joints in the body. They have the freest range of motion, they are the only ones that can turn on their axis. However, the disadvantage of ball joints is that the free range of motion makes them more susceptible to dislocation than less mobile human joints. In these places, fractures are more common.

Some synovial types of human joints must be considered separately.

trochlear joint

Block joints are a class of synovial. These are the ankles, knee and elbow joints of a person. Typically, a trochlear joint is a ligament of two or more bones where they can only move in one axis to flex or straighten.

The simplest block-like joints in the body are interphalangeal, they are located between the phalanges of the fingers and toes.

Because they have little body mass and mechanical strength assigned to them, they are made up of simple synovial material with tiny extra ligaments for reinforcement. Each bone is covered with a thin layer of smooth hyaline cartilage, designed to reduce friction in the joints. The bones are also surrounded by a capsule of tough fibrous connective tissue covered by a synovial membrane.

The structure of the human joint is always different. For example, the elbow joint is more complex, being formed between the humerus, radius and ulna of the forearm. The elbow is subjected to more severe stress than the joints of the fingers and toes, therefore it contains several strong additional ligaments and unique bone structures that strengthen its structure.

The ulna and radius collateral ligaments help support the ulna and radius and strengthen the joints. Human legs also consist of several large block-like joints.

The elbow-like ankle joint is located between the tibia and fibula in the lower leg and the talus in the leg. Branches of the tibia fibula form a bony socket around the talus to limit movement of the leg in one axis. Four additional ligaments, including the deltoid, hold the bones together and strengthen the joint to support the weight of the body.

Located between the thigh and the tibia and fibula of the lower leg, the knee joint is the largest and most complex trochlear joint in the human body.

The elbow joint and ankle joint, whose anatomy is similar, are most often prone to osteoarthritis.

Ellipsoid joint

An ellipsoid joint, also known as a flat joint, is the most common form of synovial joint. They are formed near bones that have a smooth or almost smooth surface. These joints allow the bones to slide in any direction - up and down, left and right, diagonally.

Due to their structure, ellipsoid joints are flexible, while their movement is limited (to prevent injury). Ellipsoid joints are lined with a synovial membrane that produces a fluid that lubricates the joint.

Most ellipsoid joints are found in the appendicular skeleton between the carpal bones of the wrist, between the carpal joints and metacarpal bones of the hand, between the bones of the ankle.

Another group of ellipsoid joints is located between the faces of twenty-six vertebrae in the intervertebral joints. These connections allow us to flex, extend, and rotate the torso while maintaining the strength of the spine, which supports the weight of the body and protects the spinal cord.

Condylar joints

There is a separate type of ellipsoid joints - the condylar joint. It can be considered a transitional form from a block-shaped joint to an ellipsoid one. The condylar joint differs from the block joint in a large difference in the shape and size of the articulating surfaces, as a result of which movement around two axes is possible. The condylar joint differs from the ellipsoid joint only in the number of articular heads.

saddle joint

The saddle joint is a type of synovial joint where one of the bones is shaped like a saddle and the other bone rests on it like a rider on a horse.

Saddle joints are more flexible than ball or ellipsoid joints.

The best example of a saddle joint in the body is the carpometacarpal joint of the thumb, which is formed between the trapezoid bone and the first metacarpal bone. In this example, the trapezium forms a rounded saddle on which the first metacarpal sits. The carpometacarpal joint allows a person's thumb to easily cooperate with the other four fingers of the hand. The thumb is, of course, extremely important to us, as it is what allows our hand to grip objects firmly and use many tools.

ball joint

Ball joints are a special class of synovial joints that have the highest freedom of movement in the body due to their unique structure. The human hip and shoulder joint are the only ball-and-socket joints in the human body.

The two main components of the ball joint are the bone with the ball head and the bone with the cup-shaped notch. Consider the shoulder joint. Human anatomy is so arranged that the spherical head of the humerus (upper arm bone) fits into the glenoid cavity of the scapula. The glenoid cavity is a small and shallow depression that gives the shoulder joint the greatest range of motion in the human body. It is surrounded by a ring of hyaline cartilage, which is the flexible reinforcement of the bone, while muscles—the cuffs of the rotator cuff—hold the humerus within the socket.

The hip joint is somewhat less mobile than the shoulder, but is a stronger and more stable joint. Additional stability of the hip joint is needed to support the weight of the person's body on their feet while performing activities such as walking, running, etc.

At the hip joint, the rounded, almost spherical head of the femur (femur) fits snugly against the acetabulum, a deep recess in the pelvic bone. A sufficiently large number of rigid ligaments and strong muscles hold the head of the femur in place and resist the most severe stresses in the body. The acetabulum also prevents hip dislocations by limiting the movement of the bone within it.

Based on the above, you can make a small table. The structure of the human joint will not be included in it. So, in the first column of the table the type of joint is indicated, in the second and third - examples and their location, respectively.

Human joints: table

To make it clearer what the human joints are, we will describe some of them in more detail.

elbow joint

Human elbow joints, the anatomy of which has already been mentioned, require special attention.

The elbow joint is one of the most complex joints in the human body. It is formed between the distal end of the humerus (more precisely, its articular surfaces - the block and condyle), the radial and block-shaped notches of the ulna, as well as the head of the radius and its articular circumference. It consists of three joints at once: the humeroradial, humeroulnar and proximal radioulnar.

The humeroulnar joint is located between the trochlear notch of the ulna and the block (articular surface) of the humerus. This joint belongs to the block-shaped and is uniaxial.

The shoulder joint is formed between the condyle of the humerus and the head of the humerus. Movements in the joint are made around two axes.

The promaximal radioulnar connects the radial notch of the ulna and the articular circumference of the head of the radius. It is also uniaxial.

There are no lateral movements in the elbow joint. In general, it is considered a trochlear joint with a helical sliding shape.

The largest of the upper body are the elbow joints. Human legs also consist of joints, which simply cannot be ignored.

hip joint

This joint is located between the acetabulum on the pelvic bone and the femur (its head).

This head is covered with hyaline cartilage almost throughout, except for the fossa. The acetabulum is also covered with cartilage, but only near the lunate surface, the rest of it is covered with synovial membrane.

The following ligaments belong to the hip joint: ischio-femoral, ilio-femoral, pubic-femoral, circular zone, as well as a ligament of the femoral head.

The iliofemoral ligament originates at the inferior anterior iliac bone and ends at the intertrochanteric line. This ligament is involved in maintaining the trunk in an upright position.

The next ligament, the ischio-femoral, begins at the ischium and is woven into the capsule of the hip joint itself.

A little higher, at the top of the pubic bone, the pubic-femoral ligament begins, which goes down to the capsule of the hip joint.

Inside the joint itself is a ligament of the femoral head. It starts at the transverse ligament of the acetabulum and ends at the fossa of the femoral head.

The circular zone is made in the form of a loop: it is attached to the lower anterior iliac bone and surrounds the neck of the femur.

The hip and shoulder joints are the only ball joints in the human body.

Knee-joint

This joint is formed by three bones: the patella, the distal end of the femur and the proximal end of the tibia.

The capsule of the knee joint is attached to the edges of the tibia, femur and patella. It is attached to the femur under the epicondyles. On the tibia, it is fixed along the edge of the articular surface, and the capsule is attached to the patella in such a way that its entire anterior surface is outside the joint.

Ligaments of this joint can be divided into two groups: extracapsular and intracapsular. Also in the joint there are two lateral - tibial and peroneal collateral ligaments.

Ankle joint

It is formed by the articular surface of the talus and the articular surfaces of the distal ends of the fibula and tibia.

The articular capsule is attached almost throughout its entire length to the edge of the articular cartilage and recedes from it only on the anterior surface of the talus. On the lateral surfaces of the joint are its ligaments.

The deltoid, or medial ligament, consists of several parts:

- posterior tibio-talar, located between the posterior edge of the medial malleolus and the posterior medial parts of the talus;

- anterior tibio-talar, located between the anterior edge of the medial malleolus and the posteromedial surface of the talus;

- tibiocalcaneal part, extends from the medial malleolus to the support of the talus;

- tibia-navicular part, originates from the medial malleolus and ends at the dorsum of the navicular bone.

The next ligament, calcaneofibular, extends from the outer surface of the lateral malleolus to the lateral surface of the neck of the talus.

Not far from the previous one is the anterior talofibular ligament - between the anterior edge of the lateral malleolus and the lateral surface of the neck of the talus.

And last, the posterior talofibular ligament originates at the posterior edge of the lateral malleolus and ends at the lateral tubercle of the process of the talus.

In general, the ankle joint is an example of a trochlear joint with helical motion.

So, now we definitely have an idea of ​​what human joints are. The anatomy of the joints is more complicated than it seems, and you can see for yourself.

fb.ru

shoulder joint

It is the most mobile in humans and is formed by the head of the humerus and the glenoid cavity of the scapula.

The articular surface of the scapula is surrounded by a ring of fibrous cartilage - the so-called articular lip. The tendon of the long head of the biceps brachii passes through the joint cavity. The shoulder joint is strengthened by a powerful coraco-shoulder ligament and surrounding muscles - deltoid, subscapular, supra- and infraspinatus, large and small round. The pectoralis major and latissimus dorsi muscles also take part in the movements of the shoulder.

The synovial membrane of the thin articular capsule forms 2 extra-articular torsion - the tendons of the biceps of the shoulder and the subscapularis. The anterior and posterior arteries enveloping the humerus and the thoracoacromial artery take part in the blood supply of this joint, the venous outflow is carried out into the axillary vein. The outflow of lymph occurs in the lymph nodes of the armpit. The shoulder joint is innervated by branches of the axillary nerve.

In the shoulder joint, movements around 3 axes are possible. Flexion is limited by the acromial and coracoid processes of the scapula, as well as the coracobrachial ligament, extension by the acromion, coracobrachial ligament, and joint capsule. Abduction in the joint is possible up to 90°, and with the participation of the girdle of the upper extremities (with the inclusion of the sternoclavicular joint) - up to 180°. The abduction stops at the moment the large tubercle of the humerus abuts against the coracoid-acromial ligament. The spherical shape of the articular surface allows a person to raise the arm, take it back, rotate the shoulder along with the forearm, the hand in and out. This variety of hand movements was a decisive step in the process of human evolution. The shoulder girdle and shoulder joint in most cases function as a single functional entity.

hip joint

It is the most powerful and heavily loaded joint in the human body and is formed by the acetabulum of the pelvic bone and the head of the femur. The hip joint is strengthened by the intra-articular ligament of the head of the femoral brush, as well as the transverse ligament acetabulum, covering the neck of the femur. Outside, a powerful ilio-femoral, pubic-femoral and ischio-femoral ligaments are woven into the capsule.

The blood supply to this joint is carried out through the arteries that envelop the femur, branches of the obturator and (inconsistently) branches of the superior perforating, gluteal and internal pudendal arteries. The outflow of blood occurs through the veins surrounding the femur, into the femoral vein and through the obturator veins into the iliac vein. Lymph drainage is carried out to the lymph nodes located around the external and internal iliac vessels. The hip joint is innervated by the femoral, obturator, sciatic, superior and inferior gluteal, and pudendal nerves.
The hip joint is a type of ball-and-socket joint. It allows movements around the frontal axis (flexion and extension), around the sagittal axis (abduction and adduction) and around the vertical axis (external and internal rotation).

This joint is under heavy load, so it is not surprising that its lesions occupy the first place in the general pathology of the articular apparatus.

Knee-joint

One of the largest and most complex human joints. It is made up of 3 bones: the femur, tibia, and fibula. Stability of the knee joint is provided by intra- and extra-articular ligaments. The extra-articular ligaments of the joint are the peroneal and tibial collateral ligaments, the oblique and arcuate popliteal ligaments, the patellar ligament, and the medial and lateral patella ligaments. The intraarticular ligaments include the anterior and posterior cruciate ligaments.

The joint has many auxiliary elements, such as menisci, intra-articular ligaments, synovial folds, synovial bags. Each knee joint has two menisci, one external and one internal. The menisci have the form of crescents and perform a shock-absorbing role. The auxiliary elements of this joint include synovial folds, which are formed by the synovial membrane of the capsule. The knee joint also has several synovial bags, some of which communicate with the joint cavity.

Everyone had to admire the performances of gymnasts and circus performers. People who can climb into small boxes and bend unnaturally are said to have gutta-percha joints. Of course, this is not so. The authors of The Oxford Handbook of Body Organs assure readers that "in such people the joints are phenomenally flexible" - in medicine this is called joint hypermobility syndrome.

The shape of the joint is a condylar joint. It allows movements around 2 axes: frontal and vertical (with a bent position in the joint). Flexion and extension occur around the frontal axis, and rotation occurs around the vertical axis.

The knee joint is very important for human movement. With each step, by bending, it allows the foot to step forward without hitting the ground. Otherwise, the leg would be brought forward by raising the hip.

According to the World Health Organization, every 7th inhabitant of the planet suffers from joint pain. Between the ages of 40 and 70, joint disease occurs in 50% of people and in 90% of people over 70 years of age.
According to www.rusmedserver.ru, meddoc.com.ua

See also:

7 early signs of arthritis

8 ways to ruin your knees

www.liveinternet.ru

General subtleties

In general, the joint is formed by two joints: the first, main, femoral-tibial, the second is formed by the femur and patella. The joint is complex, it is condylar in type. The joint moves in three mutually perpendicular planes, the first, which is also the most important, is the sagittal one, in which flexion and extension occur, which is carried out in the range from 140 to 145 degrees.

In the frontal plane, there is abduction, adduction, it is insignificant, it is only 5 degrees. In the horizontal plane, rotation occurs inside, outside, small movements are possible in a bent position. From a normal or neutral, bent position, rotation is possible no more than 15-20 degrees.
Additionally, there are two more types of movements, which are represented by sliding, rolling of the articular surfaces of the condyles of the tibia in relation to the femur, occur from the front, back, and vice versa.

Biomechanics

The anatomy of the joint is impossible without an understanding of biomechanics, the treatment is based on this. It is complex, its essence lies in the simultaneous movement in several planes. If a person tries to straighten the leg from 90 to 180 degrees, then due to the ligaments, there is a rotation, displacement in front or to the other side of any part of the tibial plateau.

The structure is such that the condyles of both bones are not ideal in relation to each other, so the range of motion increases significantly. Stabilization occurs due to the presence of many ligaments, complemented by adjacent muscles.
Inside the cavity there are menisci, strengthening occurs due to the capsular-ligamentous apparatus, which is covered on top with a muscle-tendon complex.

Soft tissue structures

This is a complex of soft tissues, which, performing a specific function, provide range of motion. These include a large number of formations that have their own structure. In general, children's and adult joints do not differ in their structure.

menisci

These formations consist of connective tissue cartilage, roughly speaking, this is a gasket located between the smooth surfaces of the condyles of the femur, tibia. Their anatomy is such that they contribute to the elimination of incongruence. In addition, their structure involves depreciation, redistribution of the load on the entire surface of the bones. Due to all of the above, the human knee is stabilized, the synovial fluid evenly moves through the joint.

Along their periphery, the menisci are tightly connected to the capsule with the help of ligaments. They differ in strength, because the maximum load falls on the periphery.
During movement, the menisci move along the surface of the tibial plateau, this process does not occur during rupture, therefore, treatment is required. The menisci are reinforced with collateral, cruciate ligaments.

The free edge of the meniscus faces the center, the children's joint, unlike the adult, contains blood vessels. The menisci of an adult have them only along the periphery, which is no more than 1/4. The capsule surrounds everything, which has folds, bags, liquid is produced in them. It is nutrition, a lubricant for cartilage, its total amount does not exceed a teaspoon. Folds replace the cavities of the knee, create additional cushioning.

Ligament apparatus

In the cavity of the knee joint there are formations - cruciate, paired ligaments. They are separated from the cavity with the help of the synovial membrane. Thickness 10 mm, length 35 mm. The anatomy of the human anterior cruciate ligaments is such that they begin with a wide base on the inner or medial surface of the femoral condyle located outwards. Further, their structure differs in that they go from top to bottom inwards, attaching to the anterior surface of the intercondylar eminence on the tibia.

The structure of the ligaments is based on a large number of fibers, which, when combined, form two main bundles. During movement, the load is experienced by each individual bundle of ligaments. Thus, not only the muscles are involved in strengthening the joint, preventing dislocation of the bones. Normally, the anterior cruciate ligament, by its tension, prevents even minimal subluxation of the external condyle, the plateau of the tibia, when the joint is in the most vulnerable position.

The posterior cruciate ligament is 15 mm thick and up to 30 mm long. The beginning takes in the anterior part of the inner condyle of the thigh, following down, outward, is attached to the posterior surface of the intercondylar eminence behind the tuberosity. The structure of the posterior ligament involves the interweaving of part of the fibers into the joint capsule.

The posterior cruciate ligament does not allow the tibia to move backwards, its hyperextension. When a ligament is ruptured in a person, this kind of movement becomes possible, the degree of rupture determines the treatment. The bundle also includes two bundles of fibers.

Extra-articular ligaments

On the inside, the knee is strengthened not only by muscles, but also by the internal collateral ligament. It contains two portions - superficial, deep. The first portion plays the role of a joint stabilizer, consisting of long fibers that fan out from the inner condyle of the thigh, gradually pass to the tibia. The second portion is formed by short fibers, partially woven into the area of ​​the menisci of the human joint. With a complete rupture of the ligament, the treatment is reduced to surgery.

On the outer surface, the human joint is strengthened by external or lateral collateral ligaments. Partially, the fibers of this ligament pass to the back surface, where they participate in additional strengthening. A child's joint contains more elastic fibers in the ligaments of the joint.

muscles

In dynamic terms, in addition to ligaments, muscles are involved in stabilizing the joint. They surround the joint on both sides, complicating its structure. With a partial rupture, the muscles of the knee in a person contribute to its additional stabilization. All muscles have their strength. But the most powerful is the quadriceps, which is involved in the formation of the patellar ligaments.

With pathology, the muscles, especially the quadriceps, begin to atrophy, strength decreases. During the rehabilitation period, treatment is aimed at restoring its function, as the most important.

When it is necessary to repair the posterior instability of the knee, the main treatment is to strengthen the joint after damage to any part of the posterior cruciate ligament. The composition of the posterior muscle group includes semimembranosus, semitendinosus, tender, which are located on the inside of a person, the biceps is located on the outer surface of the thigh.

Norm and pathology of the knee

Understanding the processes occurring in the joint optimizes the treatment, making it more effective. It is not enough to know the structure of a human joint, how it functions matters. An adult, children's joint has articular surfaces that are covered with highly differentiated hyaline cartilage. It consists of chondrocytes, collagen fibers, ground substance, growth layer.
The load that falls on the cartilage is evenly distributed between all components. The structure according to this principle allows you to transfer the load by pressure or shearing nature.

The structure of the knee can be significantly affected by an injury, the mechanism of which largely depends on the treatment. Cartilage can be damaged as a result of excessive impact during sudden braking at the moment of rotation. When the ligaments are damaged, the joint becomes unstable, it begins to shift to the sides. An additional factor complicating treatment can be hemarthrosis, in which blood accumulates in the cavity of the knee joint. The dead cells lead to the release of a large number of lysosomal enzymes, which ultimately leads to the destruction of joint structures.

Basically, in the joint, as a result of external causes, its cartilage is damaged. The degree of damage depends on the strength, duration of the damaging factor. Cracks appear, which are the gates for further destruction of collagen fibers. Vessels sprout from any part of the bone, they lead to a decrease in restorative capacity. The bone is also subject to destruction processes.

The joint has a complex macroscopic, microscopic structure, function, understanding of which helps to treat it correctly.

drpozvonkov.ru

Anatomy and joint movement

Every movement in a person's life is regulated by the central nervous system, then the signal is transmitted to the required muscle group. In turn, it sets the required bone in motion. Depending on the freedom of movement of the axis of the joint, an action is performed in one direction or another. The cartilages of the articular surfaces increase the diversity of movement functions.

A significant role is played by muscle groups that contribute to the movement of the joints. Ligaments by structure consist of dense tissue, they provide additional strength and shape. The blood supply passes through the large main vessels of the arterial network. Large arteries branch into arterioles and capillaries, bringing nutrients and oxygen to the articulation and periarticular tissues. Outflow occurs through the venous vascular system.

There are three main directions of movement, they determine the functions of the joints:

1. Sagittal axis: performs the function of abduction - adduction;
2. Vertical axis: performs the function of supination - pronation;
3. Frontal axis: performs the function of flexion - extension.

The structure and forms of joints in medicine are usually divided into classes in a simple way. Joint classification:

• Uniaxial. Block type (phalanges of fingers), cylindrical joint (radio-elbow joint).
• Biaxial. Saddle joint (carpometacarpal), elliptical type (radiocarpal).
• Multi-axis. Spherical joint (hip, shoulder), flat type (sternoclavicular).

Types of joints

For convenience, all joints of the human body are usually divided into types and types. The most popular division is based on the structure of human joints, it can often be found in the form of a table. The classification of individual types of human joints is presented below:

• Rotary (cylindrical type). The functional basis of movement in the joints is supination and pronation around one vertical axis.
• Saddle type. Articulation refers to this type of connection, when the ends of the surfaces of the bones sit astride each other. The amount of movement occurs axially along its ends. Often there are such joints at the base of the upper and lower extremities.
• Spherical type. The structure of the joint is represented by a convex head on one bone and a hollow on the other. This articulation belongs to multiaxial joints. The movements in them are the most mobile of all, and are also the freest. It is represented in the human body by the hip and shoulder joints.
• Complex joint. In humans, this is a very complex joint, which is a complex of the body of two or more simple joints. Between them, the articular layer (meniscus or disc) is substituted on ligaments. They hold the bone one near the other, preventing movements to the sides. Types of joints: kneecap.
• Combined joint. This connection consists of a combination of several different in shape and isolated from one another joints that perform joint functions.
• Amphiarthrosis, or tight joint. It has a group of strong joints. The articular surfaces sharply limit the movements in the joints for greater density, there are practically no movements. In the human body, they are represented where movements are not needed, but a fortress is needed for protective functions. For example, the sacral joints of the vertebrae.
• Flat type. This form of joints in humans is represented by smooth, perpendicularly placed joint surfaces in the articular bag. The axes of rotation are possible around all planes, which is explained by the insignificant dimensional difference of the articulating surfaces. These are the bones of the wrist, for example.
• Condylar type. Joints whose anatomy has at its base a head (condyle), similar in structure to an ellipse. This is a kind of transitional form between the block-shaped and elliptical types of the structure of the joints.
• block type. The articulation here is a cylindrically located process against the lying cavity on the bone and is surrounded by the articular bag. It has a better connection, but less axial mobility than the spherical type of connection.

The classification of joints is quite complicated, because there are a lot of joints in the body and they have a variety of shapes, perform certain functions and tasks.

Connection of cranial bones

The human skull has 8 paired and 7 non-paired bones. They are interconnected by dense fibrous sutures, except for the bones of the lower jaws. The development of the skull occurs as the organism grows. In newborns, the bones of the skull roof are represented by cartilaginous tissue, and the sutures still bear little resemblance to a connection. With age, they get stronger, gradually turning into hard bone tissue.

The bones of the front part adjoin to each other smoothly and are connected by even seams. Unlike them, the bones of the brain section are connected by scaly or jagged sutures. The lower jaw is attached to the base of the skull with a complex elliptical complex biaxial combined joint. Which allows you to move the jaw along all three types of axes. This is due to the daily process of eating.

Joints of the spinal column

The spine is made up of vertebrae, which form articulations with their bodies. The atlas (the first vertebra) is attached to the base of the skull with the help of the condyles. It is similar in structure to the second vertebra, which is called the epistopheus. Together they create a unique mechanism that is unique to humans. It promotes tilting and turning of the head.

The classification of the joints of the thoracic region is represented by twelve vertebrae, which, with the help of spinous processes, are attached to each other and to the ribs. The articular processes are directed frontally, for better articulation with the ribs.

The lumbar region consists of 5 large vertebral bodies, which have a great variety of ligaments and joints. In this department, intervertebral hernias most often occur, due to improper loads and poor muscle development in this area.

Next, follow the coccygeal and sacral sections. In the prenatal state, they are cartilaginous tissue, divided into a large number of parts. By the eighth week they merge, and by the ninth they begin to ossify. At the age of 5–6 years, the coccygeal region begins to ossify.

The entire spine in the sacral region is formed by the age of 28. At this time, separate vertebrae fuse into one department.

The structure of the joints of the belt of the lower extremities

Human legs are made up of many joints, both large and small. They are surrounded by a large number of muscles and ligaments, have a developed network of blood and lymphatic vessels. The structure of the lower limb:

1. The legs have many ligaments and joints, of which the most mobile is the spherical hip joint. It is him, in childhood, that little gymnasts and gymnasts begin to confidently develop. The largest ligament here is the femoral head. In childhood, it stretches unusually, and this is the reason for the early age of gymnast competitions. At an early level of pelvic formation, the ilium, pubic and ischium bones are laid. They are connected at first by the joints of the girdle of the lower extremities into a bone ring. Only by the age of 16-18 they ossify and fuse into a single pelvic bone.
2. In medicine, the knee is the most complex and heaviest in structure. It consists of three bones at once, which are in a deep interlacing of joints and ligaments. The knee capsule of the joint itself forms a series of synovial bags, which are located along the entire length of adjacent muscles and tendons that do not communicate with the cavity of the joint itself. The ligaments located here are divided into those that enter the joint cavity and those that do not. At its core, the knee is a condylar type of joint. When it acquires an unbent position, it already works as a block type. When the ankle is bent, rotational movements already occur in it. The knee joint claims to be the most complex joint. At the same time, it must be carefully protected, not zealous with overloads on the legs, because it is very, very difficult to restore it, and at a certain stage it is even impossible.
3. Concerning the ankle joint, it must be borne in mind that the ligaments lie on its lateral surfaces. It combines a large number of large and small bones. The ankle joint is a blocky type in which helical movement is possible. If we talk about the foot itself, then it is divided into several parts, and does not represent any complex articular joints. In its composition, it has typical block-like joints located between the bases of the phalanges of the fingers. The articular capsules themselves are free and are located along the edges of the articular cartilage.
4. The foot in human life is the subject of daily stress, and also has an important depreciation effect. It is made up of many small joints.

The structure of the joints of the belt of the upper limbs

The hand includes many joints and ligaments that are able to very finely regulate the actions and motor skills of the smallest movements. One of the most difficult joints here is the shoulder. It has many fastenings and weaves of ligaments that are difficult to adjust one on one. The main three large ligaments that are responsible for abduction, adduction, raising the arms to the sides, anteriorly and upwards.

Raising the arm above the shoulder, sets in motion the muscles and ligaments of the scapula. The shoulder is connected to the scapula with a powerful fibrous ligament, which allows a person to perform various complex and difficult actions with weights.

The classification of the elbow joint in its structure is very similar to the construction of the knee joint. Includes three joints surrounded by one base. The heads at the base of the bones in the elbow joint are covered with hyaline cartilage, which improves gliding. In the cavity of a single joint, blocking of the fullness of movement is distinguished. Due to the fact that the elbow joint involves the movement of the humerus and ulna, lateral movements are not fully performed. They are inhibited by collateral ligaments. The interosseous membrane of the forearm also takes part in the movement of this joint. Overlying nerves and blood vessels pass through it to the end of the arm.

The muscles of the wrist and metacarpus take their beginning of fastening near the wrist joint. Many thin ligaments regulate the motor skills of movement both on the back of the hand and on the sides.

The thumb joint was inherited from monkeys. Human anatomy is similar to the structure of our ancient relatives with this particular joint. Anatomically, it is due to grasping reflexes. This articulation of bones helps to interact with many objects in the environment.

Joint diseases

In humans, the joints are perhaps the most commonly affected by disease. Hypermobility should be singled out among the main pathologies. This is such a process when there is an increased activity of the joints of the bones, which goes beyond the limits of the permissible axes. An unwanted stretching of the ligaments occurs, allowing the joint to make a deep movement, which is extremely bad for the tissues adjacent to the heads of the bones. After some time, such movements lead to deformation of the joint surfaces. This disease is inherited, in what way, it remains to be seen by doctors and scientists.

Hypermobility is often detected in young girls and is genetically determined. It leads to deformation of the connective tissues and, above all, the joints of the bones.

With this type of illness, it is highly recommended not to choose a job in which you have to be in the same position for a long time. In addition, it is necessary to exercise carefully, as there is a risk of even greater overstretching of the ligaments. Which, in turn, ends with varicose veins or arthrosis.

The most common localization of diseases:

1. Diseases of the shoulder girdle often occur in people in old age, especially in those who are used to earning a living by hard physical labor. In the critical zone are also people who go to the gym very often. Subsequently, old age is accompanied by pain in the shoulders (brachial arthritis) and osteochondrosis of the cervical spine. Often, doctors find osteoarthritis or arthritis of the shoulder joint in people of this category.
2. Elbow diseases are also common among athletes (epicondylitis). By old age, a person's joints experience discomfort and limited mobility. They are caused by deforming osteoarthritis, arthritis and inflammation of the muscles of the hand. Therefore, it is necessary to remember the correct technique and time of classes.
3. The joints of the hands, fingers, and hands become inflamed in rheumatoid arthritis. The disease is manifested by the syndrome of "tight gloves". Its peculiarity is the defeat of both hands. Cases of arthrosis with acute damage to the tendons occur in professions associated with fine motor skills: musicians, jewelers, as well as those who daily type texts on the keyboard for a long time.
4. In the hip region, coxarthrosis is most often isolated. A characteristic disease in the elderly is osteoporosis (softening of the structure of the femur). Bursitis and tendonitis of the hip joint are found in runners and football players.
5. Diseases in the knee are detected in people of all age groups, as this is a very complex complex. Its restoration in 90% of cases is impossible without surgical intervention, which, in turn, does not guarantee a complete cure for this compound.
6. Arthrosis and subluxation are characteristic of the ankle. Pathologies are professional in dancers, women who often use high heels. Osteoarthritis affects people who are obese.

Healthy joints are a luxury in our time, which is difficult to notice until a person is faced with their problem. When every movement in a certain joint is done with pain, then a person is able to give a lot to restore health.

It would be difficult to imagine human life without precise and confident movements. Concerning any profession where the physical skill of a person is involved, one must pay tribute to the help of joints and ligaments. They are activated reflexively, and we almost never notice how the slightest movements decide our fate, from driving a car to complex surgical operations. In all this, we are helped by the joints, which can turn life the way you want.

The basis of the structure of a living organism is the skeleton, which includes mobile joints, as well as bone and cartilage tissues. Human joints are important and necessary in order to walk, perform complex and well-coordinated movements in everyday work and professional activities. Arthrology is a complex science that studies all types of anastomoses with bones, a brief general explanation of which is mandatory for everyone.

Species, their anatomy and structure

A good example of studying the structure of bone anastomoses in the human body is the synovial joint. Clinical human anatomy divides all structural components into 2 types:

• Main elements:
  • articular surfaces - areas on the bones with which they are in contact (head and cavity);
  • articular cartilage - protects against destruction due to friction;
  • capsule - is a protection, is responsible for the production of synovia;
  • cavity - a gap between surfaces filled with liquid;
  • synovia - softens the friction of bones, nourishes cartilage, supporting metabolism.
• Auxiliary formations:
  • cartilaginous disc - a plate that divides the cavity into two halves.
  • menisci - play the role of a shock absorber, are located in the knee;
  • articular lip - a border of cartilage around the articular cavity;
  • ligamentous connecting apparatus - controls movements;
  • large and small muscles.

The joints and ligaments of the limbs have received the most complete development, since they take on the main functional abilities of a person in life and adaptation in society. In the process of evolution, the human hand was formed from the forelimb of mammals.

Functions and tasks

Different types of human joints, their diverse anatomical design are of fundamental importance for a number of functional duties performed by bone joints. All actions are divided into the performance of such functions as:

• The combination of bones, teeth and cartilage with each other makes them a strong shock absorber.
• Prevention of bone destruction.
• Performing axial movements, including:
  • frontal - flexion, extension;
  • sagittal - adduction, abduction;
  • vertical - supination (outward movement), pronation (inward);
  • circular movements - moving the stroke from axis to axis.
• Physical activity of a person, which ensures the correct structure of the joint.
• Maintaining the position of the skeleton.
• Influence on the growth and development of the body.

Classification, its principles

There are many compounds in the body, each has its own characteristics and performs specific functions. The most convenient in clinical practice is the classification of joints into types and types, which the table successfully depicts. It did not include continuous intercartilaginous connections of the ribs, ranging from the 6th to the 9th.

The combined type should be noted separately, it includes the joint of the rib head and costovertebral joints. In the latter, the tubercle of the rib connects with the transverse process of the vertebra and makes it not very mobile.

Connection types

Joints are also divided according to the following criteria:

• Mobility:
  • synarthrosis - immovable;
  • amphiarthrosis - inactive;
  • diarthrosis - mobile.
• Movement axes:
  • uniaxial joints;
  • biaxial;
  • triaxial.
• Biomechanical properties:
  • simple;
  • complicated;
  • complex.

Major joints in the human body

Hip

Connects parts of the pelvis with the head of the femur, which are covered with cartilage and synovial membrane. Spherical, paired, multiaxial joint of the lower extremities. Axes of movement - frontal, sagittal, vertical, circular rotations. The joint capsule is attached in such a way that the acetabular lip and the femoral neck are located in the joint cavity. The connecting component is represented by the ligament of the femoral head, pubic-femoral, ilio-femoral, ischio-femoral and circular zone.

Knee design diagram

The complex, condylar, largest joint on the limbs of the lower girdle is arranged with the participation of the patella, the proximal edge of the tibia and the distal -. Anatomical ligaments of the knee joint are represented by three groups:

• Lateral - collateral small and tibial.
• Extracapsular (posterior) - patellar ligament, arcuate, supporting lateral-medial, popliteal.
• Intracapsular - transverse knee ligament and cruciate.

Provides rotation and movement in the frontal axis. It has a number of synovial bags, the number and size of which are individual. The folds of the synovial membrane accumulate adipose tissue. The surfaces of the joint are covered with cartilage. A distinctive feature is the presence of external and internal sickle-shaped parts of cartilage, which are called menisci.

Ankle

A mobile joint in which the distal epiphyses (bottom) of the fibula and tibia are connected to the human foot, namely the talus. Block-shaped, involved in the movements of the frontal and sagittal axes. The ligaments are represented by two groups: the lateral, which includes the talofibular and calcaneal-fibular ligaments, and the medial or deltoid ligament. - the main area of ​​injury in athletes who move continuously.

saddle

A kind of synovial anastomosis, reminiscent of a rider on a horse - matching the name. Another bone is impaled on a saddle-shaped bone. They are flexible compared to others. A striking example of a joint that the human musculoskeletal system has is the metacarpal joint of the thumb. Here the trapezoid bone acts as a saddle, and the 1st metacarpal bone is placed on it. The opposed thumb on the upper limbs is a distinctive feature of a person, which distinguishes him from the animal world, and thanks to which it is possible to do work, including mastering new professions.

Paired elbow

A complex movable articulation of the humerus with the radius and ulna, which consists of 3 joints at once, surrounded by one capsule. Among them:

• humeroradial - a spherical joint, responsible for movements in two axes along with the elbow;
• humeroulnar - block-shaped, helical;
• proximal radioulnar - rotational joint of the 1st type.

The largest joint of the upper half of the body, which provides movement of the upper limbs and corresponds to their number. Anatomically, it is considered block-shaped with helical slides, lateral movements in it are impossible. Auxiliary elements are represented by two collateral ligaments - radial and ulnar.

Globular

This includes the hip and shoulder connection of the bones (multiaxial structures), which have the greatest mobility. The name of this group was determined by an obligatory bone element resembling a ball: in the 1st example it is the head of the humerus, in the 2nd example it is the head of the femur. The common elements of the structure are represented by a spherical head at the end of one bone and a bowl-shaped depression on the second. The shoulder joint has the greatest range of free motion in the skeleton, it is simple in structure, and the hip joint is less mobile, but stronger and more resilient.

blocky

Types of joints that are synovial. This includes the knee, elbow, ankle and less complex sections with good mobility - the interphalangeal joints of the arms and legs. These joints, to the extent of their characteristics, are endowed with work of lesser strength and hold an insignificant mass, which is standard for their structure - small ligaments, hyaline cartilage, a capsule with a synovial membrane.

elliptical

A type of joint, also known as a flat joint, is formed by bones with an almost smooth surface. In the joint space, the synovium is constantly functioning, which is produced by the membrane. These mobile joints contribute to a limited range of motion in all directions. Representatives of the group are intervertebral, carpal, carpometacarpal joints in the human body.

Condylar

A separate subspecies of the ellipsoid class. It is considered a transitional type from block-shaped. A distinctive feature from the 1st is the discrepancy between the shape and size of the connecting surfaces, from the ellipsoidal one - by the number of heads of the structure. There are two examples of such joints in the body - temporomandibular and knee, the latter moves around 2 axes.

Common diseases, their causes and symptoms

Diagnosis of joint diseases

Based on the following methods and techniques:

• Complaints.
• Disease history.
• General examination, palpation.
• Goniometry is a characteristic of free range of motion.
• Mandatory laboratory tests:
  • general blood analysis;
  • blood biochemistry, C-reactive protein, erythrocyte sedimentation reaction, antinuclear antibodies, uric acid are especially important;
  • general urinalysis.
• Radiation research methods:
  • radiological;
  • arthrography;
• Radionuclide.

Treatment of ailments

Therapy is effective only with a correct diagnosis and if the diagnosis is not late. The table of the main diseases highlights the cause, which should be treated. When there are foci of infection, antibiotics are prescribed. In the autoimmune process, immunosuppressants are used - monoclonal antibodies, corticosteroids, cytostatics. Degenerative conditions are corrected by chondroprotectors. Take non-steroidal anti-inflammatory drugs that affect calcium levels and bone strength. Rehabilitation is provided by physical therapy and physiotherapy. Surgical treatment is used after the exhaustion of conservative methods, but it does not guarantee the complete blocking of any pathological process.

joints- movable joints of the bones of the skeleton- are its integral components and represent two or more contact surfaces. There are different types of joints; some of them are immobile, but most joints in the human body are mobile or semi-mobile, and each performs a specific function. There are about 200 joints in the human body, thanks to which it is possible to move various parts of the body and move around.

In some cases, along the edge of the joint, the ends of the bones do not fit tightly to each other, forming gaps. These gaps are filled with additional cartilaginous liners - menisci. They perform a stabilizing joint and shock-absorbing function. The largest menisci are found in the knee joints. However, there are other joints that contain menisci, such as the temporomandibular, sternoclavicular, or acromioclavicular joints.

Depending on the building joints can be divided into two types: simple and complex.

Simple joints- joints of the bones of the skeleton without intra-articular inclusions. For example, the head of the humerus and the articular fossa of the scapula are connected by a simple joint, in the cavity of which there are no inclusions.

Compound joints- joints of the bones of the skeleton, in which there are intra-articular inclusions in the form of discs (temporomandibular joint), menisci (knee joint) or small bones (carpal and tarsal joints).

According to the degree of mobility There are three main types of joints: fixed, semi-movable and movable.

Stiff joints (synarthrosis). Fixed joints are securely connected to the bones and consist of two or more components; their main task is to form a protective layer for soft tissues - for example, the joints of the bones of the skull protect the brain.

Semi-mobile joints (amphiarthrosis). The bony surfaces are not exactly connected to each other, but are separated by a fibrocartilaginous tissue that allows only slight movement of the bones, as happens with vertebrae separated by intervertebral discs: since each joint is slightly mobile, the entire spine can tilt forward or sideways.

Movable joints (diarrhoea). Can perform various movements; to this type of joints belong the joints of the limbs: shoulder, hip, elbow and knee. According to the shape and location of the associated bone segments, different types of mobile joints are distinguished: each joint is responsible for specific types of movements.

According to the structure and type of connection bone segments distinguish types of joints:

Globular: consists of a bone spherical segment, as if included in the notch; such a joint can be moved in any direction - for example, the hip joint, in which the femur is connected to the hip.

Condylar: consists of a bone segment with a rounded or elliptical head, which is included in another concave bone segment, for example, the joint of the radius with the humeral condyle.

Blocky: formed by the union of a block-shaped bone segment stretched toward the center and another ridge-like bone segment that penetrates deeply into the first bone segment, such as the joint in the ulna, the junction of the ulna and humerus.

Single axis: the surfaces in contact are smooth and even, therefore they can only slide one over the other - for example, the first two cervical vertebrae atlas and axis.

In mobile joints, in addition to bone segments, there are also tissues and essential elements necessary for the functionality of the joint.

The shoulder joint is one of the most mobile joints in the human body, so a person can perform many movements with his hand.