The human body is a harmonious system. Thanks to the correct arrangement of its parts, all the functions necessary for life are carried out. The main support of the body is the skeleton. The next most important component are the joints and ligaments. Thanks to these formations, people are able to make any movements.
The joints of the upper limbs are numerous. Most of them are observed in the area of the hands and fingers. However, in order to set the entire upper limb in motion, the work of the three main joints is expended: the shoulder, elbow and wrist. The anatomy of these formations is complex, because they are composed of many parts (bones, ligaments, muscles, nerves and blood vessels).
What is the elbow joint?
Anatomy of the elbow joint, shoulder joint, as well as the wrist joint, is a well-coordinated mechanism that has several components. Each of these formations is important. Only thanks to the correct structure of the entire joint, it can carry out its functions. anomaliesor diseases of the bone tissue or ligamentous apparatus lead to impaired movement of the upper limb. The same applies to pathologies of blood vessels and nerves.
Anatomy of the elbow joint includes 3 bones, several ligaments, a capsule and muscles. For the functioning of each of these formations, blood supply and innervation are necessary. Like any part of the body, it has vessels and nerves and an elbow joint.
Its anatomy is designed so that all components jointly carry out a single function - the movement of a limb. In general, the concept of "elbow" includes not only the joint, but also the forearm. Thanks to the coordinated work of these formations, it can perform the following functions:
- Upper limb flexion.
- Pronation and supination.
- Arm extension.
- From- and adduction of the forearm.
Elbow bones and joints
Anatomy of the elbow joint is difficult because it is a complex articulation. This is primarily due to the fact that it consists of 3 bones. In addition, each of them is connected using small joints. All of them are under a special capsule - a bag.
You can visually consider this formation in a special atlas. There you can see all the joints that make up the elbow joint. Anatomy (photos in the atlas help to better understand it) of this formation is presented there in various angles and sections, so that its entire structure is clear.
The bone included in the described joint and located on top(proximal) is called the shoulder. It starts from the shoulder blade and ends at the level of the elbow. Refers to the tubular bones of the skeleton. If we consider it in a cross section, we can see that the lower part has the shape of a triangle. In this zone there is an articular surface. Its middle part is connected to the ulna and forms a small joint. It is called the humeroulnar joint.
On the side (laterally) there is a connection with the radius. There, too, there is a joint called the humeroradial joint. The two bones that make up the elbow joint on the distal side are also connected to each other. They form the third articulation - the proximal radioulnar. And all the listed formations are covered with a bag.
What ligaments form the elbow?
In addition to bones, the anatomy of the elbow joint includes a ligamentous apparatus. They are connective tissue fibers, which are also necessary for movement. Here are the following links:
- Radiation collateral. It starts from the protruding part (condyle) of the ulna, which is located on the side. Further, the ligament descends below and goes around the head of the radius. After that, it is attached to the cutout on it.
- Elbow collateral. Like the first, it originates from the condyle of the humerus (internal). After that, she goes down. This formation ends in a block-shaped notch.
- Annular ligament of the radius. She is betweenfront and back cutouts. The fibers of this ligament cover the radius, thereby attaching it to the ulna.
- Square. Helps connect the neck of the radius to the notch of the elbow.
- Interosseous membrane of the forearm. It is a dense connective tissue that is necessary for fixation. Occupies the entire space between the ulna and the radius.
Muscles that make up the elbow joint
Muscles are organs thanks to which a person can perform flexion and extension of limbs. The anatomy of the elbow joint includes striated musculature, although the muscles are not part of the articulation itself. Nevertheless, they are its integral part, since without them the joint cannot perform its function. The muscles are located in the proximal and distal region, that is, above and below the articulation itself. Among them:
- Shoulder. It is located slightly above the joint. Thanks to it, flexion movements of the forearm are carried out.
- Biceps muscle (biceps). It starts in the upper part of the humerus, is well felt when the arm is tensed. Belongs to the group of flexors.
- Three-headed. Responsible for the movement of the forearm.
- Elbow muscle. Needed for joint extension.
- Flexus carpi ulnaris
- Round pronator. Participates in forearm flexion.
- Long palmar muscle. Some people don't have it. This muscle is needed to extend the forearm and palm.
- Superficial finger flexor.
- The brachioradialis muscle. Responsible fortwists and bends.
- Supinator muscle. It is located in the bony region of the forearm.
- Extensor radialis long and short.
Thanks to all of them, the upper limb moves. Therefore, they should also be attributed to the anatomical formations of the elbow. After all, muscles are involved in the movement of the forearm.
What are bags of the elbow joint: anatomy
All anatomical formations of the elbow joint are enclosed in the so-called bag. It consists of a synovial membrane, inside of which there is a fluid. The cavity of the bag includes all 3 articulations of the bones. As a result, a single joint is formed - the elbow.
In turn, each of the three small joints is also enclosed in bags. By the way, this shell is present in all joints of our body. It protects the bones and ligaments from damage. And the fluid inside the bag is necessary to lubricate the articular surfaces. Thanks to synovial fluid, bones and joints are not damaged by collision (during movement).
Which arteries supply the elbow
In order for all the formations that make up the elbow to function, blood flow is necessary. It is carried out with the help of three large vessels. Among them: the brachial, ulnar and radial arteries. Each of them, in turn, has branches. In general, the elbow joint is supplied with blood by 8 arteries extending from the three main ones. Some of them provide oxygen to the muscles. Others supply blood to bones and joints.
All these vessels formnetwork - anastomosis. As a result, if one of them is damaged, blood still flows to the organ. However, anastomoses between arteries do not always help with injuries. This is because heavy bleeding from the vascular network is difficult to stop.
All arteries are located on the surface of the joint bag. Thanks to them, the entire joint is fed with oxygen.
Venas of the elbow joint
The venous system is distributed throughout the body. The anatomy of the elbow joint is no exception. Venous outflow from the formations that make up this articulation is carried out by vessels of the same name (with arteries). That is, blood rich in carbon dioxide from the joint area returns to the cardiac system. The following vessels are distinguished that carry out the outflow:
- lower and upper ulnar collaterals - they are branches from the brachial vein;
- return elbow - it has 2 branches (anterior and posterior). Both are part of the cubital vein;
- interosseous return;
- recurrent radial - 1 of its branches is involved in the blood supply of the elbow;
- median and radial collateral.
These vessels carry out the outflow of blood into the pools of the three main veins. They are named the same as the arteries: radial, ulnar and brachial. They all flow into the large axillary vein.
Anatomy of the elbow joint: lymph drainage (vessels and nodes)
The lymphatic system consists of vessels and ducts. also inthe body has several groups of large peripheral nodes. Among them: axillary, elbow, inguinal and other accumulations of lymphoid tissue. In addition, there are also small knots.
Lymph outflow is carried out through deep vessels. They pass next to the arteries and veins of the upper limb. The lymphatic vessels of the hand start from the palmar network, run along the bones and flow into the ulnar nodes. Further, the outflow continues at shoulder level. The fluid then collects in the axillary lymph nodes. After that, there is an outflow to the subclavian trunk. Further - to the right and left lymphatic ducts.
Innervation of the shoulder and elbow joints
To understand exactly how the movements of the forearm are carried out, it is necessary to study such a section as the anatomy of the elbow joint. The innervation of this joint is represented by three main formations. They, in turn, subdivide into small branches.
The radial and median nerves run along the front of the elbow. The first one performs 2 functions. It sets in motion the extensor muscles of the elbow and wrist joint, and is also responsible for the sensitivity of the back of the forearm and half of the hand. The median nerve runs through almost the entire upper limb. Basically, it activates the flexor muscles of the palm and fingers, as well as the pronator round. The third major nerve is the ulnar. In the distal section, it passes into the palmar branch, which sets the 4th and 5th fingers in motion. Its proximal part innervates the muscles of the forearm.
Anatomical features of the structure of the elbow in children
Anatomy of the elbow joint in children is no different from adults. However, this joint in a child is more prone to injury. And most often there are dislocations of the elbow joint. This is due to the fact that the synovial tissue in children is not sufficiently formed, unlike adults. As a result of stretching the arm in babies, the head of the radial bone is displaced. Basically, this phenomenon is observed at the age of 1 to 3 years. And it is more common in girls.
How the elbow joint in dogs works
The anatomy of the elbow joint of a dog is similar to that of a human. This articulation is problematic for animals and veterinarians. A feature of the elbow in dogs is the predisposition of the articular tissue to dysplasia. This disease is common in many breeds. It refers to congenital developmental anomalies. With dysplasia, there is a gradual destruction of tissues, as a result of which the pathology leads the animal to lameness.
