Human joints: types, anatomy, structure. Auxiliary elements of the joint Complex and combined joints

With the presence of a gap between the articulating bones. A joint is a type of bone articulation; another type of articulation - a continuous connection of bones (without a joint space) - is called synarthrosis. Joints perform both supporting and motor functions.

Rice. 1. Structure of the joint: 1 - articular cartilage; 2 - fibrous membrane of the joint capsule; 3 - ; 4 - joint cavity; 5 - ends of articulating bones (epiphyses); 6 - periosteum.

Rice. 2. Types of hand joints:
1 - ellipsoidal;
2 - saddle-shaped;
3 - spherical;
4 - block-shaped.

The main elements of the joint are articular surfaces(ends) of connecting bones, articular capsules lined from the inside with synovial membrane (see), and articular cavities (Fig. 1). In addition to these main elements that form the joint, there are also auxiliary formations (discs, menisci, etc.), which are not found in all joints.

The ends of the articulating bones (epiphyses) form the solid base of the joint and, due to their structure, can withstand heavy loads. Hyaline cartilage, 0.5-2 mm thick, covering the articular surfaces and very firmly connected to the bone, ensures a more complete fit of the ends of the bones during movement and acts as a shock absorber in the supporting joints.

The articular capsule closes the joint cavity, attaching to the edges of the articular surfaces of the connecting bones. The thickness of this capsule varies. In some joints it is tight, in others it is loose. There are two layers in the capsule: the inner synovial and the outer fibrous, consisting of dense. In a number of places, the fibrous layer forms thickenings - ligaments (see). Along with the ligaments that are part of the capsule, extra-articular and intra-articular ligaments also take part in strengthening the joints. The joints are further strengthened by the passing muscles and their tendons.

The articular cavity in the form of a slit contains small quantity synovial fluid, which is produced by the synovial membrane and is a transparent, viscous, yellowish liquid. It serves as a lubricant for the articular surfaces, reducing friction during joint movements.

The auxiliary apparatus of the joint, along with ligaments, is represented by intra-articular cartilage (menisci, discs, articular labrum), which, located between the articular ends of bones or along the edge of the joint, increase the area of ​​​​contact of the epiphyses, make them more consistent with each other and play big role in joint mobility.

The blood supply to the joints occurs due to the branches of the nearest arteries; they form a dense network of anastomoses in the articular capsule. Outflow there's blood coming out along the veins into adjacent venous trunks. Lymphatic drainage occurs through a network of small lymphatic vessels into the nearest lymphatic collectors.

The innervation of the joints is provided by the spinal and sympathetic nerves.

The function of the joints is determined mainly by the shape of the articulating surfaces of the epiphyses of the bones. The articular surface of one bone is like an imprint of another; in most cases, one surface is convex - the articular head, and the other is concave - the articular cavity. These surfaces do not always completely correspond to each other; often the head has greater curvature and vastness than the cavity.

If two bones take part in the formation of a joint, then such a joint is called simple; If more bones - complex.

According to their shape, the articular surfaces of the bones are compared with geometric figures and, accordingly, joints are distinguished: spherical, ellipsoidal, block-shaped, saddle-shaped, cylindrical, etc. Movements can be carried out around one, two and three axes, forming one- (cylindrical and block-shaped), two- (ellipsoidal and saddle-shaped) and multi-axial (ball-and-socket) joints (Fig. 2). The number and position of axes determine the nature of the movements. There are movements around the frontal axis - flexion and extension, the sagittal axis - adduction and abduction, the longitudinal axis - rotation and multi-axis rotational movement.

articulationes synoviales are the most advanced types of bone connections. They are distinguished by great mobility and a variety of movements.

Joint structure

Each joint includes articular surfaces of bones covered with cartilage, an articular capsule, and an articular cavity with a small amount of synovial fluid. Some joints also have auxiliary formations in the form of articular discs, menisci and articular labrum.

The articular surfaces, fades articulares, in most cases of articulating bones correspond to each other - they are congruent (from the Latin congruens - corresponding, coinciding).

Articular cartilage, cartilago articularis, is usually hyaline, in individual joints (temporomandibular) it is fibrous, and has a thickness of 0.2-6.0 mm.

The articular capsule, capsula articularis, is attached to the articulating bones near the edges of the articular surfaces or at some distance from them; it firmly fuses with the periosteum, forming a closed articular cavity.

The articular cavity, cavum articulare, is a slit-like space between the articular surfaces covered with cartilage.

Articular discs and menisci, disci et menisci articulares, are cartilaginous plates of various shapes that are located between articular surfaces that do not completely correspond to each other (incongruent). The disc is usually a solid plate, fused along the outer edge with the articular capsule, and, as a rule, divides the articular cavity into two chambers (two floors).

Menisci

These are semi-lunar-shaped, continuous cartilaginous or connective tissue plates that are wedged between the articular surfaces.

The articular lip, labrum articulare, is located along the edge of the concave articular surface, complements and deepens it (for example, in shoulder joint). It is attached with its base to the edge of the articular surface, and with its inner concave surface facing the joint cavity.

Shapes of articular surfaces

resemble segments of the surfaces of various geometric bodies: a cylinder, an ellipse, a ball. Accordingly, joints are distinguished according to the shape of the articular surfaces: cylindrical, ellipsoidal and spherical. There are also variants of the indicated forms of joints. For example, a type of cylindrical joint would be a trochlear joint, a spherical joint would be a cup-shaped and flat joint.

The shape of the articular surfaces determines the number of axes, around which movement occurs at a given joint. Thus, the cylindrical shape of the articular surfaces allows movement only around one axis, and the ellipsoidal shape allows movement around two axes. In joints with spherical articular surfaces, movements are possible around three or more mutually perpendicular axes.

Thus, there is a certain interdependence between the shape of the articulating surfaces and the number of axes of motion.

Biomechanical classification of joints:

1) joints with one axis of movement (uniaxial);

2) joints with two axes of movement (biaxial);

3) joints with many axes of movement, of which three are main (multiaxial, or triaxial).

Human joints are the basis of every body movement. They are found in all bones of the body (the only exception is the hyoid bone).

Their structure resembles a hinge, due to which the bones slide smoothly, preventing their friction and destruction.

A joint is a movable connection of several bones, and in the body there are more than 180 of them in all parts of the body.

They are immobile, partially movable, and the main part is represented by movable joints.

The degree of mobility depends on the following conditions:

• volume of connecting material;
• type of material inside the bag;
• shapes of bones at the point of contact;
• the level of muscle tension, as well as ligaments inside the joint;
• their location in the bag.

How is the joint structured? It looks like a bag of two layers that surrounds the junction of several bones. The bursa ensures the tightness of the cavity and promotes the production of synovial fluid.

It, in turn, acts as a shock absorber for bone movements.

Together they perform three main functions of the joints: they help stabilize the body position, are part of the process of movement in space, and ensure the movement of parts of the body in relation to each other.

Basic elements of a joint

The structure of human joints is complex and is divided into the following basic elements: cavity, capsule, surface, synovial fluid, cartilage, ligaments and muscles. We'll talk briefly about each below.

1. The joint cavity is a slit-like space, which is hermetically sealed and filled with synovial fluid.
2. Joint capsule - consists of connective tissue that envelops the connecting ends of the bones. The capsule is formed on the outside from a fibrous membrane, but inside it has a thin synovial membrane (a source of synovial fluid).
3. Articular surfaces - have special form, one of them is convex (also called the head), and the second is pit-shaped.
4. Synovial fluid. its function is to lubricate and moisturize surfaces; it also plays an important role in fluid exchange. It is a buffer zone during various movements (pushing, jerking, squeezing). Provides both sliding and divergence of bones in the cavity. A reduction in the amount of synovium leads to a number of diseases, bone deformations, loss of a person’s ability to perform normal physical activities and, as a result, even disability.
5. Cartilage tissue (thickness 0.2 - 0.5 mm). The surfaces of the bones are covered with cartilage tissue, the main function of which is shock absorption during walking and sports. The anatomy of cartilage is represented by connective tissue fibers that are filled with fluid. This, in turn, nourishes the cartilage when it is at rest, and during movement it releases fluid to lubricate the bones.
6. Ligaments and muscles are auxiliary parts of the structure, but without them the normal functionality of the entire body is impossible. With the help of ligaments, bones are fixed without interfering with movements of any amplitude due to their elasticity.

The inert protrusions around the joints also play an important role. Their main function- limitation of range of motion. As an example, consider the shoulder. IN humerus there is a bony tubercle. Due to its location next to the process of the scapula, it reduces the range of motion of the arm.

Classification and types

In the process of development of the human body, way of life, mechanisms of interaction between man and external environment, the need to perform various physical actions and the result was a variety of types of joints. The classification of joints and its basic principles are divided into three groups: the number of surfaces, the shape of the end of the bones, and functionality. We'll talk about them a little later.

The main type in the human body is the synovial joint. His main feature- connection of bones in the bag. This type includes shoulder, knee, hip and others.

There is also a so-called facet joint. Its main characteristic is the limitation of rotation to 5 degrees and tilt to 12 degrees.

The function also consists of limiting the mobility of the spine, which helps maintain the balance of the human body.

By structure

In this group, the classification of joints occurs depending on the number of bones that connect:

• A simple joint is a connection between two bones (interphalangeal bones).
• Complex – a connection of more than two bones (elbow). The characteristics of such a connection imply the presence of several simple bones, while the functions can be implemented separately from each other.
• Complex joint - or two-chamber, which contains cartilage that connects several simple joints (lower jaw, radioulnar). Cartilage can separate the joints either completely (disc shape) or partially (meniscus in the knee).
• Combined - combines isolated joints that are placed independently of each other.

According to the shape of the surfaces

The shapes of the joints and the ends of the bones have different shapes geometric shapes(cylinder, ellipse, ball).

Depending on this, movements are carried out around one, two, or three axes. There is also a direct relationship between the type of rotation and the shape of the surfaces.

1. Cylindrical joint - the surface has the shape of a cylinder, rotates around one vertical axis(parallel to the axis of the connected bones and the vertical axis of the body). This species may have a rotational name.
2. Block joint - a cylinder-shaped joint (transverse), one axis of rotation, but in the frontal plane, perpendicular to the connected bones. Characteristic movements are flexion and extension.
3. Helical is a variation of the previous type, but the axes of rotation of this form are located at an angle other than 90 degrees, forming helical rotations.
4. Ellipsoidal - the ends of the bones have the shape of an ellipse, one of them is oval, convex, the second is concave. Movements occur in the direction of two axes: bend-unbend, abduct-adduct. The ligaments are perpendicular to the axes of rotation.
5. Condylar is a type of ellipsoidal. The main characteristic is the condyle (a rounded process on one of the bones), the second bone is in the form of a depression, and can differ significantly in size from each other. the axis of rotation is represented by the frontal one. The main difference from the block-shaped one is the strong difference in the size of the surfaces, from the ellipsoidal one - the number of heads of connecting bones. This type has two condyles, which can be located either in the same capsule (similar to a cylinder, similar in function to the trochlear one) or in different capsules (similar to the ellipsoidal one).
6. Saddle-shaped - formed by connecting two surfaces as if “sitting” on each other. One bone moves lengthwise, while the second moves across. Anatomy involves rotation around perpendicular axes: flexion-extension and abduction-adduction.
7. Ball-and-socket joint - the surfaces are shaped like balls (one convex, the other concave), due to which people can make circular movements. Basically, rotation occurs along three perpendicular axes, the intersection point being the center of the head. The peculiarity is a very small number of ligaments, which does not interfere with circular rotations.
8. Cup-shaped - the anatomical appearance suggests deep depression one bone that covers most of the area of ​​the head of the second surface. As a result, there is less free mobility compared to the spherical one. Necessary for greater joint stability.
9. Flat joint - flat ends of bones of approximately the same size, interaction along three axes, the main characteristic is a small range of movements and surrounded by ligaments.
10. Tight (amphiarthrosis) - consists of bones of different sizes and shapes that are closely connected to each other. Anatomy - inactive, the surfaces are represented by tight capsules, non-elastic short ligaments.

By nature of movement

In view of their physiological characteristics joints perform many movements along their axes.

In total, there are three types in this group:

• Uniaxial - which rotate around one axis.
• Biaxial - rotation around two axes.
• Multi-axis - mainly around three axes.

In addition, there are also different types joint movements:

• Flexion and extension.
• Rotation in and out.
• Abduction and adduction.
• Circular movements (surfaces move between axes, the end of the bone draws a circle, and the entire surface draws the shape of a cone).
• Sliding movements.
• Removal from one another (for example, peripheral joints, distance of fingers).

The degree of mobility depends on the difference in the size of the surfaces: than larger area one bone over another, the greater the range of motion.

Ligaments and muscles can also inhibit range of motion.

Their presence in each type is determined by the need to increase or decrease the range of motion of a certain part of the body.

"An Illustrative Review of Anatomy"

In the next video you can visually study the anatomy and see how the joints on the skeleton work.

Source: https://prospinu.com/anatomija/stroenie-sustava.html

Structure and functions of joints

Joint- is a movable articulation of two or more skeletal bones.

Joints unite the bones of the skeleton into a single whole. More than 180 help a person move various joints. Together with bones and ligaments, they are classified as the passive part of the musculoskeletal system.

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 collapsing, which is a very painful and dangerous process.

In the human body, joints play a triple role: they help maintain body position, participate in the movement of body parts relative to each other, and are organs of locomotion (movement) of the body in space.

The main elements that are present in all so-called true joints are:

• articular surfaces (ends) of connecting bones;
• joint capsule;
• articular cavity.

The joint cavity is filled with synovial fluid, which is a kind of lubricant and promotes free movement of the articular ends.

Based on the number of articular surfaces, they are distinguished:

1. a simple joint having only 2 articular surfaces, e.g. interphalangeal joints;
2. a complex joint that has more than two articulating surfaces, such as the elbow joint. A complex joint consists of several simple joints in which movements can be performed separately;
3. a complex joint containing intra-articular cartilage that divides the joint into 2 chambers (bicameral joint).

Classification of joints is carried out according to the following principles:

• by the number of articular surfaces;
• according to the shape of the articular surfaces;
• by function.

The articular surface of the bone is formed by hyaline (less often fibrous) articular cartilage. Articular cartilage is tissue filled with fluid.

The surface of the cartilage is smooth, strong and elastic, capable of absorbing and releasing liquid well.

The thickness of articular cartilage is on average 0.2-0.5 millimeters.

The joint capsule is formed by connective tissue. It surrounds the articulating ends of the bones and on the articular surfaces passes into the periosteum.

The capsule has a thick outer fibrous fibrinous membrane and an inner thin synovial membrane, which secretes synovial fluid into the joint cavity.

The ligaments and tendons of the muscles strengthen the capsule and promote movement of the joint in certain directions.

The auxiliary formations of the joint include intra-articular cartilage, discs, menisci, lips and intracapsular ligaments.

The blood supply to the joint comes from a widely anastomosing (branched) articular arterial network formed by 3-8 arteries.

The innervation (supply of nerves) of the joint is carried out by a nervous network formed by sympathetic and spinal nerves. All articular elements, except hyaline cartilage, have innervation.

They contain significant amounts of nerve endings that carry out pain perception, as a result of which they can become a source of pain.

Joints are usually divided into 3 groups:

1. synarthrosis - motionless (fixed);
2. amphiarthrosis (half-joints) - partially mobile;
3. diarthrosis (true joints) - mobile. Most joints are movable joints.

According to the World Health Organization, every 7th person on the planet suffers from joint pain. Between the ages of 40 and 70 years, joint diseases are observed in 50% of people and in 90% of people over 70 years of age.

A synovial joint is a joint in which the ends of the bones meet in the articular capsule. These include most human joints, including weight-bearing joints - the knee and hip joints.

Joints are divided into simple and complex. Simple bones are formed by 2 bones, while complex bones are formed by more than 2 bones. If several independent joints are involved in the movement, as in the lower jaw when chewing, such joints are called combined.

A combined joint is a combination of several joints isolated from each other, located separately, but functioning together.

These are, for example, both temporomandibular joints, proximal and distal radioulnar joints, and others.

In shape, the articular surfaces resemble segments of the surfaces of geometric bodies: a cylinder, an ellipse, a ball. Depending on this, cylindrical, ellipsoidal and spherical joints are distinguished.

The shape of the articular surfaces determines the volume and direction of movements around 3 axes: sagittal (runs from front to back), frontal (runs parallel to the plane of support) and vertical (perpendicular to the plane of support).

Circular motion is a sequential movement around all axes. In this case, one end of the bone describes a circle, and the entire bone - a cone shape.

Sliding movements of the articular surfaces are also possible, as well as moving them away from each other, as is, for example, observed when stretching the fingers.

The function of a joint is determined by the number of axes around which movements occur.

The following main types of joint movements are distinguished:

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

The human hand contains: 27 bones, 29 joints, 123 ligaments, 48 ​​nerves and 30 named arteries. We move our fingers millions of times throughout our lives. 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 articular cavity of the scapula.

The articular surface of the scapula is surrounded by a ring of fibrocartilage - the so-called articular lip. The tendon of the long head of the biceps brachii muscle passes through the joint cavity.

The shoulder joint is strengthened by the powerful coracohumeral ligament and surrounding muscles - deltoid, subscapularis, supra- and infraspinatus, teres major and minor.

The pectoralis major and latissimus dorsi muscles also take part in shoulder movements.

The synovial membrane of the thin articular capsule forms 2 extra-articular inversions - the tendons of the biceps brachii and subscapularis.

The anterior and posterior circumflex humeral arteries and the thoracoacromial artery take part in the blood supply to this joint. venous drainage carried out into the axillary vein.

Lymph drainage occurs in lymph nodes axillary region. The shoulder joint is innervated by branches of the axillary nerve.

1. humerus;
2. shoulder blade;
3. collarbone;
4. joint capsule;
5. folds of the joint capsule;
6. acromioclavicular joint.

The shoulder joint is capable of movement around 3 axes. Flexion is limited by the acromion 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 belt upper limbs(when the sternoclavicular joint is included) - up to 180°. Abduction stops when the greater tuberosity of the humerus rests on the coracoacromial ligament.

The spherical shape of the articular surface allows a person to raise his arm, move it back, and rotate the shoulder along with the forearm and 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 formation.

Hip joint

It is the most powerful and heavily loaded joint in the human body and is formed by the acetabulum. pelvic bone and the head of the femur.

The hip joint is strengthened by the intra-articular ligament of the femoral head, as well as transverse ligament acetabulum, which surrounds the neck of the femur.

From the outside, the powerful iliofemoral, pubofemoral and ischiofemoral ligaments are woven into the capsule.

The blood supply to this joint is through the circumflex femoral arteries, branches of the obturator and (variably) 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. Lymphatic drainage occurs in 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 experiences a lot of stress, so it is not surprising that its lesions occupy first place in the general pathology of the articular apparatus.

Knee joint

One of the largest and most complex human joints. It is formed by 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 fibular and tibial collateral ligaments, the oblique and arcuate popliteal ligaments, the patellar ligament, and the medial and lateral suspensory ligaments of the patella.

The intra-articular ligaments include the anterior and posterior cruciate ligaments.

The joint has many auxiliary elements, such as menisci, intra-articular ligaments, synovial folds, and bursae. Each knee joint has 2 menisci - external and internal.

The menisci look like crescents and play 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 bursae, some of which communicate with the joint cavity.

Everyone had to admire the performances artistic gymnasts and circus performers. People who are able to climb into small boxes and bend unnaturally are said to have gutta-percha joints.

• femur
• tibia
• synovial fluid
• internal and external menisci
• medial ligament
• lateral ligament
• cruciate ligament
• patella

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 carried forward by raising the hip.

Source: http://meddoc.com.ua/stroenie-i-funkcii-sustavov/

Human joints

The basis of the structure of a living organism is the skeleton, which includes movable joints, as well as bone and cartilage tissue.

Human joints are important and necessary in order to walk and perform complex and 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.

Types, their anatomy and structure

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

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

Functions and tasks

The joints provide shock absorption during motor activity person.

Different types of human joints and their varied anatomical design are of fundamental importance for a number of functional responsibilities carried out bone joints. All actions are divided into performing functions such as:

• The combination of bones, teeth and cartilage with each other makes them a strong shock absorber of movement.
• Preventing 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 is successfully depicted in the table.

It did not include the continuous intercartilaginous connections of the ribs, starting from the 6th to the 9th.

View	Characteristic	Type	Location Features
Fibrous	Connective tissue with collagen	Suture	Skull sutures
Syndesmoses	Connects the radius and ulna of the forearm
Nail-shaped	Teeth
Cartilaginous	The structure contains hyaline cartilage or disc	Synchondrosis	Joint of rib and manubrium of sternum
Symphyseal or semi-joints	Pubic symphysis, intervertebral joints
Synovial	The joint connects the cavity, capsule, accessory ligaments, synovial fluid, bursa, tendon sheaths	Flat (sliding)	Sacroiliac
Block-shaped	Elbow, knee, humeroulnar (helical joint)
Ball	Sternocostal (cup-shaped)
Hinged (cylindrical joint)	Connects the tooth epistotheus and atlas
Condylar	Metacarpophalangeal fingers
Saddle	Metacarpal thumb
Elliptical	Radiocarpal

Connection types

Joints are also divided according to the following criteria:

Joints can be classified according to the degree of mobility.

• Mobility:
  • synarthrosis - immovable;
  • amphiarthrosis - inactive;
  • diarthrosis - mobile.
• Axes of motion:
  • uniaxial joints;
  • biaxial;
  • triaxial.
• Biomechanical properties:
  • simple;
  • difficult;
  • complex.

Major joints in the human body

Hip

The articulation connects the femur to the pelvic bone.

Connects the parts of the pelvis with the head of the femur, which are covered with cartilage and synovial membrane. Ball-and-socket, paired, multi-axial joint of the lower extremities.

Axes of movement - frontal, sagittal, vertical, circular rotation. The articular capsule is attached in such a way that the acetabular lip and femoral neck are located in the articular cavity.

The connecting component element is represented by the ligament of the femoral head, pubofemoral, iliofemoral, ischiofemoral and circular zone.

Knee design diagram

Complex, condylar, most large joint on the limbs of the lower girdle it is arranged with the participation of the patella, the proximal edge of the tibia and the distal edge of the femur. Anatomical ligaments knee joint presented in three groups:

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

Provides rotation and movement in the frontal axis. It has a number of synovial bursae, the number and size of which are individual.

Folds of the synovial membrane accumulate adipose tissue. The surfaces of the joint are covered with a cartilaginous layer.

A distinctive feature is the presence of outer and inner crescent-shaped parts of the cartilage, which are called menisci.

Ankle

The joint is more often injured in people actively involved in sports.

A movable joint in which the distal epiphyses (bottom) of the small and tibia with the human foot, namely the talus.

Block-shaped, involved in movements of the frontal and sagittal axes. The ligaments are represented by two groups: the lateral, which includes the talofibular and calcaneofibular ligaments, and the medial, or deltoid ligament.

The ankle joint is the main area of ​​injury in athletes who move continuously.

Saddle

A type of synovial anastomosis, reminiscent of a rider on a horse - consistent with the name. Another bone is mounted on a bone similar in shape to a saddle. They are more flexible than others.

A striking example of a joint that has musculoskeletal system human, is the metacarpal joint of the thumb. Here the trapezium bone acts as a saddle, and the 1st metacarpal bone is located on it.

Opposed thumb on the upper limbs - distinguishing feature a person, which sets him apart from the animal world, and thanks to which he has the opportunity to do work, including mastering new professions.

Paired elbow

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

1. brachioradial - a spherical joint, responsible for movements in two axes along with the elbow;
2. humeroulnar - block-shaped, screw-shaped;
3. proximal radioulnar - type 1 rotator joint.

The joint has a complex structure and has the most large size in the upper limbs.

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 are impossible in it.

Auxiliary elements are represented by two collateral ligaments - radial and ulnar.

Globular

This includes the hip and shoulder joints of the bones (multi-axial structures), which have the greatest mobility. The name of this group is determined by mandatory 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 general structural elements are represented by a spherical head at the end of one bone and a cup-shaped depression on the second. The shoulder joint has the greatest range free movements in the skeleton, it is simple in structure, and the femoral one is less mobile, but stronger and more resilient.

Block-shaped

Types of joints that are classified as synovial. This includes the knee, elbow, ankle and less complex departments with good mobility - interphalangeal joints of the arms and legs.

These joints, to the extent of their characteristics, are endowed with less force and hold a small mass, which is standard for their structure - small ligaments, hyaline cartilage, a capsule with a synovial membrane.

Elliptical

The wrist joint is of the ellipsoidal type.

The type of joint, also known as planar, is formed by bones with an almost smooth surface.

In the joint space, the synovium, which is produced by the membrane, constantly functions. These moving joints contribute to limited range of motion in all directions.

Representatives of the group are the intervertebral, carpal, and 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, and from the ellipsoidal one - the number of heads of the structure.

There are two examples of such joints in the body - the temporomandibular and the knee, the latter moves around 2 axes.

Diagnosis of joint diseases

Based on the following methods and techniques:

Goniometry allows you to determine how much a person can move a joint.

• Complaints.
• History of the disease.
• General examination, palpation.
• Goniometry is a characteristic of the free range of motion.
• Mandatory laboratory tests:
  • general blood test;
  • blood biochemistry, C-reactive protein, erythrocyte sedimentation reaction, antinuclear antibodies, uric acid are especially important;
  • General urine test.
• Radiation research methods:
  • X-ray;
  • arthrography;
• Radionuclide.

Treatment of ailments

Therapy is effective only if the diagnosis is correctly made and if the diagnosis is not late. The table of main diseases highlights the cause that should be treated. When there are foci of infection, antibiotics are prescribed.

At autoimmune process use immunosuppressants - monoclonal antibodies, corticosteroids, cytostatics. Degenerative conditions are corrected with chondroprotectors.

Take nonsteroidal anti-inflammatory drugs that affect calcium levels and bone strength. Rehabilitation is provided physical therapy and physiotherapy.

Surgical treatment is used after exhaustion conservative methods, but it does not guarantee complete blocking of any pathological process.

Based on the number of articular surfaces, they are distinguished:

1. Simple joint (art. simplex), which has only 2 articular surfaces, for example interphalangeal joints.

2. Complex joint (art. composite), which has more than two articular surfaces, for example the elbow joint. A complex joint consists of several simple joints in which movements can be performed separately. Availability in complex joint several joints are determined by the commonality of their ligaments.

3. Complex joint (art. complexa), containing intra-articular cartilage, which divides the joint into two chambers (bichamber joint). Division into chambers occurs either completely if the intra-articular cartilage has the shape of a disc (for example, in the temporomandibular joint), or incompletely if the cartilage takes the shape of a semilunar meniscus (for example, in the knee joint).

4. A combined joint is a combination of several isolated joints, located separately from each other, but functioning together. These are, for example, both temporomandibular joints, proximal and distal radioulnar joints, etc. Since a combined joint represents a functional combination of two or more anatomically separate joints, this differs from complex and complex joints, each of which, being anatomically unified, composed of functionally different compounds.

By form and by function classification is carried out as follows. The function of a joint is determined by the number of axes around which movements occur. The number of axes around which movements occur in a given joint depends on the shape of its articular surfaces. For example, the cylindrical shape of a joint allows movement only around one axis of rotation. In this case, the direction of this axis will coincide with the axis of location of the cylinder itself: if the cylindrical head is vertical, then the movement occurs around the vertical axis (cylindrical joint); if the cylindrical head lies horizontally, then the movement will occur around one of the horizontal axes coinciding with the axis of the head, for example, the frontal one (trochlear joint). In contrast, the spherical shape of the head makes it possible to rotate around multiple axes that coincide with the radii of the ball (ball-and-socket joint). Consequently, there is complete correspondence between the number of axes and the shape of the articular surfaces: 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 joint determines its shape (P.F. Lesgaft).

Joints with one axis of motion

1. A cylindrical joint (articulatio trochoidea) is a congruent joint in which the shape and size of the articulated surfaces correspond to each other and represent a segment of the surface of a body of rotation with one axis. A classic example is the articulation between the ulna and radius, where the axis of rotation extends from the head radius to the head ulna. Around this axis rotation occurs inward (pronatio) and outward (supinatio).
2. The trochlear joint (ginglymus) is the surface of a cylinder with a recess for connection with the ridge of the glenoid cavity of another bone. The presence of a recess and a cushion in the joint provides greater strength and movements are made only along one axis passing along the length of this block. Block joints include, for example, the ankle and interphalangeal joints.
3. The screw-shaped joint (articulatio cochlearis) is a type of block joint. The difference from the latter is that the guide roller and the corresponding recess form a helical direction on the cylindrical surface of the helical joint. These joints include the elbow.

Joints with two axes of motion

1. The condylar joint (articulatio condylaris) is an intermediate form of the ellipsoidal and trochlear joints. The knee and temporomandibular joints have this shape. In the knee joint, movements are possible in two axes only when the knee joint is bent.
2. Ellipsoid joint (articulatio ellipsoidea) - the articular head and socket are shaped like an egg. Movements are performed along two axes passing transversely to the length of the ellipse. The joint between the occipital bone and the first cervical vertebra has this shape.
3. The saddle joint (articulatio sellaris) is characterized by the fact that it is impossible to distinguish between the articular head and the cavity. These saddle-shaped surfaces are equivalent and lie perpendicular to each other. Movements in such a joint are performed along two mutually perpendicular axes. In humans there is a saddle joint between the I metacarpal bone The first finger of the hand and the trapezoid bone of the wrist, as well as the calcaneocuboid joint.

Joints with multiple axes of motion

1. Ball joint (articulatio spheroidea), in which the articular head forms a segment of the ball. The area of ​​the corresponding glenoid cavity is much smaller. The difference in the area of ​​the articular surfaces provides the range of movements in the joint: they are performed along three mutually perpendicular axes, which can be carried out in different planes, so the number of movements can be infinite. As a rule, in ball-and-socket joints the capsule is extensive and not strengthened by ligaments, which contributes to good mobility of the joint. For example, the shoulder joint, formed by the head of the humerus and the glenoid cavity of the scapula, has no ligaments.
2. The cup joint is a type of ball and socket joint. It is built so that the head of the bone is located in a deep articular cavity. At its edges there is a lip made of fibrous connective tissue, which further encloses the head of the bone. Movements occur in all axes, but to a lesser extent than in a ball-and-socket joint (for example, the hip joint).
3. A flat joint (articulatio plana) has slightly curved articular surfaces that correspond to each other. These surfaces represent segments of a large ball, so movements in flat joints are performed along all axes in the form of sliding with insignificant volume. Flat joints form articulations of articular processes between the vertebrae. Minor displacements of many intervertebral joints, combining, provide a large range of motion of the spine, which allows for circular movement (circumductio).
4. A semi-mobile joint (amphiarthrosis) is formed by equal articular surfaces. In such joints they are congruent. The joints are strengthened by short, strong ligaments, which limits the range of motion to 4-7°. Shocks and shocks are significantly attenuated in these joints.

Joint structure

Synovial joints (joints), articulationes synoviales, are the most advanced types of bone connections. They are distinguished by great mobility and a variety of movements. Each joint includes articular surfaces of bones covered with cartilage, an articular capsule, and an articular cavity with a small amount of synovial fluid. Some joints also have auxiliary formations in the form of articular discs, menisci and articular labrum.

Articular surfaces, fades articulares, in most cases, the articulating bones correspond to each other - they are congruent (from the Latin congruens - corresponding, coinciding).

Articular cartilage, cartilago articularis, as a rule, hyaline, in some joints (temporomandibular) - fibrous, has a thickness of 0.2-6.0 mm. It consists of three layers (zones): superficial,zone superficidlis; intermediate,zone intermedia, And deep,zone profunda.

Joint capsule, capsule articularis, attaches to articulating bones near the edges of the articular surfaces or at some distance from them; it firmly fuses with the periosteum, forming a closed articular cavity. The capsule has two layers: outer - fibrous membrane,membrane fibrosa (stratum fibrosum), and internal - synovial membrane,membrane synovialis (stratum synoviale).

Articular cavity, cavum articulare, It is a slit-like space between the articular surfaces covered with cartilage. It is limited by the synovial membrane of the joint capsule and contains a small amount of synovial fluid.

Articular discs and menisci, disci et menisci articulares, - these are cartilaginous plates of various shapes that are located between articular surfaces that do not fully correspond to each other (incongruent). The disc is usually a solid plate, fused along the outer edge with the articular capsule, and, as a rule, divides the articular cavity into two chambers (two floors). Menisci are semi-lunar-shaped, continuous cartilaginous or connective tissue plates that are wedged between the articular surfaces.

Articular labrum, labrum articulare, located along the edge of the concave articular surface, complements and deepens it (for example, in the shoulder joint). It is attached with its base to the edge of the articular surface, and with its inner concave surface facing the joint cavity.

Joints are located in the skeleton where distinct movements occur: flexion (lat. flexio) and extension (lat. extensio), abduction (lat. abductio) and casting (lat. adductio), pronation (lat. pronatio) and supination (lat. supinatio), rotation (lat. circumflexio). As an integral organ, the joint takes an important part in supporting and motor functions. All joints are divided into simple, formed by two bones, and complex, which is an articulation of three or more bones.

Structure

Each joint is formed by the articular surfaces of the epiphyses of the bones, covered with hyaline cartilage, an articular cavity containing a small amount of synovial fluid, articular capsule and synovial membrane. In the cavity of the knee joint there are menisci - these cartilaginous formations increase the congruence (compliance) of the articular surfaces and are additional shock absorbers that soften the effect of shocks.

Main elements of the joint:

• epiphyses of bones forming a joint
• joint capsule
• joint cavity

Articular surfaces

Articular surfaces(lat. facies articulares) articulating bones are covered with hyaline (less often fibrous) articular cartilage 0.2-0.5 mm thick. Constant friction maintains smoothness, facilitating the sliding of the articular surfaces, and the cartilage itself, thanks to its elastic properties, softens shocks, acting as a buffer.

Joint capsule

Articular cavity

Articular cavity- a slit-like hermetically sealed space limited by the synovial membrane and articular surfaces. The articular cavity of the knee joint contains the menisci.

Periarticular tissues

Periarticular tissues- these are the tissues directly surrounding the joint: muscles, tendons, ligaments, blood vessels and nerves. They are sensitive to any internal and external negative influences; disturbances in them immediately affect the condition of the joint. The muscles surrounding the joint provide direct movement of the joint and strengthen it from the outside. Numerous connective tissue intermuscular layers pass through nerve pathways, circulatory and lymphatic vessels, nourishing the joints.

Joint ligaments

Joint ligaments- strong, dense formations that strengthen the connections between bones and limit the range of motion in the joints. The ligaments are located on outside articular capsule, in some joints (knee, hip) are located inside to provide greater strength.

The blood supply to the joint is carried out from a widely anastomosing (branched) articular arterial network formed by 3-8 arteries. The joint is innervated by its nervous network formed by sympathetic and spinal nerves.

All articular elements (except for hyaline cartilage) have innervation, in other words, they contain significant numbers of nerve endings that, in particular, carry out pain perception, and therefore can become a source of pain.

Classification of joints

According to the current anatomical and physiological classification, joints are distinguished:

• By number of articular surfaces,
• By shape of articular surfaces And
• By functions.

By number of articular surfaces:

• Simple joint (lat. articulatio simplex) - has two articular surfaces, for example the interphalangeal joint of the thumb
• Compound joint (lat. articulatio composite) - 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 Temporomandibular joint
• Combined joint - a combination of several isolated joints located separately from each other, for example the temporomandibular joint

By function and shape of articular surfaces:

• Uniaxial joints:

1. Cylindrical joint (lat. art.cylindrica), for example atlanto-axial median
2. Trochlear joint (lat. art.ginglymus), for example interphalangeal joints of the fingers
3. A helical joint, as a type of trochlear joint, for example the humeroulnar joint

• Biaxial joints:

1. Elliptical (lat. art.ellipsoidea), for example wrist joint
2. Condylar (lat. art.condylaris), for example knee joint
3. Saddle-shaped (lat. art.sellaris), for example, the carpometacarpal joint of the first finger

• Multi-axis joints:

1. spherical (lat. art.spheroidea), for example Shoulder joint
2. Cup-shaped, like a type of ball-shaped, such as the hip joint
3. Flat (lat. art.plana), for example intervertebral joints.

Cylindrical joint

Cylindrical joint (rotator cuff) - a cylindrical articular surface, the axis of which is located in the vertical axis of the body or parallel to the long axis of the articulating bones and provides movement around one (vertical) axis - rotation (lat. rotation) .

Trochlear joint

Trochlear joint- the articular surface is a cylinder lying in the frontal plane, located perpendicular to the long axis of the articulating bones.

Elliptical joint

Elliptical joint- articular surfaces have the form of elliptical segments (one convex and the other concave), which provide movement around two mutually perpendicular axes.

Condylar joint

Condylar joint- has a convex articular head, in the form of a protruding process (condyle), close in shape to an ellipse. The condyle corresponds to a depression on the articular surface of another bone, although their surfaces may differ significantly from each other. The condylar joint can be considered as a transitional form from the trochlear joint to the ellipsoid joint.

Saddle joint

Saddle joint- formed by two saddle-shaped articular surfaces sitting “astride” each other, one of which moves along and across the other, making movement in two mutually perpendicular axes possible.

Ball and socket joint

Ball and socket joint- one of the articular surfaces is convex spherical the head, and the other, a correspondingly concave articular cavity. Theoretically, movement in this type of joint can be carried out around many axes, but in practice only three are used. The ball and socket joint is the loosest of all joints.

Flat joint

Flat joint- have practically flat articular surfaces (a ball surface with a very large radius), so movements are possible around all three axes, but the range of movements due to the slight difference in the areas of the articular surfaces is insignificant.

Tight joint

Tight joint (amphiarthrosis) - represent a group of joints with various shapes articular surfaces with a tightly stretched capsule and a very strong auxiliary ligamentous apparatus, closely adjacent articular surfaces sharply limit the range of movements in this type of joint. Tight joints smooth out shocks and soften shocks between bones.

Joint diseases

Joint hypermobility- increased joint mobility; stretching of the articular ligaments, allowing the joint to make more extensive movements beyond the limits of its anatomical capabilities. As a result, elements of contacting cartilaginous surfaces can produce characteristic clicks. This extensibility of the articular ligaments occurs as a result of a structural change in collagen, which becomes less strong and more elastic and becomes capable of partial deformation. This factor is of hereditary origin, but the mechanism of development of this connective tissue inferiority still remains unknown.

Hypermobility is detected mostly in women, and young ones at that. The genetic determination of hypermobility leads to changes in many tissues. First of all, joints, but also those organs that contain a lot of altered collagen. For example, such people have thin, stretchable and vulnerable skin; stretch marks easily appear on it, and they appear even in very young girls or women who have never given birth. With joint hypermobility, vascular incompetence is also observed, because their walls also consist of collagen. If it is extensible, then the blood vessels stretch very quickly under the pressure of blood. Hence, such people have early varicose veins (at 25 or even 20 years old).

People with hypermobility are not recommended to choose a job where they need to long time stay in the same position (this is especially true for teachers, salespeople, surgeons, hairdressers who stand for several hours at a time). People in these professions have a very high risk of developing varicose veins and arthrosis, and if they have hypermobility, the risk is almost one hundred percent. In addition, you need to be careful when playing sports so as not to cause even more hyperextension of the ligaments.

See also

• Hip joint (acetabulum)

Notes

Literature

• Prives M. G., Lysenkov N. K. Human anatomy. - 11th revised and expanded. - Hippocrates. - 704 p. - 5000 copies. - ISBN 5-8232-0192-3

• Vorobiev V. P. Atlas of human anatomy. - Leningrad: Medgiz, 1940. - T. Volume one. - 382 s. - 25,000 copies.

Arthrology
Continuous connections: Syndesmosis Synchondrosis Synostosis
Joints (diarthrosis):
Single axis:
Biaxial:
Multi-axis:
Torso
Scull
Hand
Leg

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Synonyms:

See what “Joint” is in other dictionaries:

JOINT, in anatomy, the place where BONES join. In movable joints such as the knees, elbows, spine, fingers and toes, the bones are separated from each other by pads of CARTILAGE. In immobile joints, cartilage may be present in... ... Scientific and technical encyclopedic dictionary

Diarthrosis, joint, knee Dictionary of Russian synonyms. joint noun, number of synonyms: 10 ankles (2) ... Dictionary of synonyms

- (articulatio), diarthrosis (diarthrosis), a structure that provides movable articulation of vertebrate bones. Simple S. are formed by two bones, complex S. by several. Basic elements of a typical C: surfaces of articulating bones, covered with cartilaginous... ... Biological encyclopedic dictionary

A movable connection between bones that allows them to move relative to each other. Auxiliary formations of ligaments, menisci and other structures... Big Encyclopedic Dictionary

JOINT, joint, man. A movable joint (see joint in 3 meanings), the place where the ends of bones are connected by cartilaginous plates and ligaments. Ushakov's explanatory dictionary. D.N. Ushakov. 1935 1940 … Ushakov's Explanatory Dictionary

JOINT, huh, husband. Movable connection of the ends of bones in humans and animals. Joint pain. | adj. articular, oh, oh. C. rheumatism. Ozhegov's explanatory dictionary. S.I. Ozhegov, N.Yu. Shvedova. 1949 1992 … Ozhegov's Explanatory Dictionary

Etc. see compose. Dahl's Explanatory Dictionary. V.I. Dahl. 1863 1866 … Dahl's Explanatory Dictionary

See COMPOSITION V. V. Vinogradov. History of words, 2010 ... History of words