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 is joints and ligaments. Thanks to these formations, people are able to make any movements.
Joints of the upper limbs are numerous. Most of them are observed in the area of the hands and fingers. Nevertheless, in order to bring the entire upper limb into motion, the work of three main joints is required: the shoulder, elbow and wrist. The anatomy of these formations is complex, because they include many parts (bones, ligaments, muscles, nerves and blood vessels).
What is the elbow joint?
The anatomy of the elbow joint, shoulder joint, as well as the wrist, is a coordinated mechanism that has several components. Each of these entities is important. Only thanks to the correct structure of the entire joint, it can carry out its functions. Anomalies or diseases of the bone tissue or ligamentous apparatus lead to impaired movements of the upper limb. The same applies to vascular and nerve pathologies.
The 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 blood vessels and nerves and an elbow joint.
Its anatomy is created so that all components together carry out a single function - limb movement. In general, the term “elbow” includes not only the joint, but also the forearm. Thanks to the coordinated work of these entities, it can carry out the following functions:
- Flexion of the upper limb.
- Pronation and supination.
- Extension of the arm.
- From - and bringing the forearm.
Bones and joints of the elbow
The anatomy of the elbow joint is difficult, as it relates to complex joints. 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 clearly see this formation in a special atlas. There you can see all the joints that make up the elbow joint. The anatomy (photos located in the atlas help to better understand it) of this education is presented there in various angles and sections, so that its entire structure is understood.
The bone entering the described joint and located on top (proximal) is called the humerus. It starts from the scapular cavity and ends at the level of the elbow. Refers to the tubular bones of the skeleton. If you look at it in a cross section, you can see that the lower part has the shape of a triangle. In this area there is a joint surface. Its middle part is connected to the ulna and forms a small joint. It is called the shoulder-elbow joint.
On the side (lateral) is the connection with the radius. There is also a joint called the brachioradial joint. The two bones that make up the elbow joint on the distal side are also interconnected. They form the third joint - the proximal radiolactic. And all together the listed formations are covered with a bag.
What are the ligaments formed elbow?
In addition to the bones, the anatomy of the elbow joint includes the ligamentous apparatus. They are connective tissue fibers, which are also necessary for the implementation of movements. Here are the following bundles:
- Beam collateral. It starts from the protruding part (condyle) of the ulnar bone, which is located on the side. Further, the ligament descends below and goes around the head of the radius. After that, she attaches to the tenderloin on it.
- Elbow collateral. Like the first, originates from the condyle of the humerus (internal). After that, she goes down. This formation ends in a blocky notch.
- The annular ligament of the radius It is located between the front and back of the tenderloin. The fibers of this ligament cover the radius, thereby attaching it to the ulnar.
- Square. Promotes the connection of the neck of the radius with the elbow.
- Interosseous membrane of the forearm. It is a dense connective tissue, which is necessary for fixation. It occupies the entire space between the ulnar and radius.
The muscles that make up the elbow joint
Muscles are organs through which a person can perform flexion and extension of the limbs. The anatomy of the elbow joint includes the striated muscles, although the muscles are not part of the joint itself. Nevertheless, they are its integral part, since without them the joint cannot carry out its function. The muscles are located in the proximal and distal region, that is, above and below the joint. Among them:
- Shoulder. It is located slightly above the joint. Thanks to her, the flexion movements of the forearm are carried out.
- Biceps muscle (biceps). It begins in the upper part of the humerus, is well palpated with tension on the arm. Refers to a group of flexors.
- Three-headed. It is responsible for the movement of the forearm.
- Ulnar muscle. It is necessary for extension of the joint.
- Elbow flexor of the wrist.
- Round pronator. Involved in flexion of the forearm.
- Long palmar muscle. Some people do not have it. This muscle is necessary for extension of the forearm and palm.
- Superficial finger flexor.
- The brachioradialis muscle. Responsible for turns and bending.
- Muscular arch support. It is located in the bony region of the forearm.
- Long and short beam extensor.
Thanks to all of them, the upper limb carries out movements. Therefore, they should also be attributed to the anatomical formations of the elbow. After all, muscles participate in the movement of the forearm.
What are Elbow Bags: Anatomy
All anatomical formations of the elbow joint are enclosed in a so-called bag. It consists of a synovial membrane, inside of which there is a liquid. The cavity of the bag includes all 3 joints 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 ligamentous apparatus from damage. And the fluid inside the bag is needed to lubricate the articular surfaces. Thanks to the synovial fluid, the bones and joints are not damaged in a collision (during movement).
What 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 using three large vessels. Among them: brachial, ulnar and radial arteries. Each of them, in turn, has branches. In general, the elbow joint is supplied with 8 arteries, departing from the three main ones. Some of them provide oxygen to muscles. Other blood supply to the bones and joints.
All these vessels form a network - anastomosis. As a result, when one of them is damaged, blood still flows to the organ. Nevertheless, anastomoses between arteries do not always help with injuries. This is because severe bleeding from a network of vessels is difficult to stop.
All arteries are located on the surface of the joint bag. Thanks to them, the entire joint is powered by oxygen.
Veins 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 joint is carried out by vessels of the same name (with arteries). That is, blood rich in carbon dioxide from the joint returns to the cardiac system. The following vessels that carry out outflow are distinguished:
- lower and upper ulnar collateral - they are branches from the brachial vein;
- return elbow - it has 2 branches (front and back). Both of them are part of the ulnar vein;
- interosseous return;
- return radiation - 1 branch is involved in the blood supply to the elbow;
- median and radial collateral.
These vessels carry out the outflow of blood into the pools of the three main veins. They are called the same as arteries: radial, ulnar and brachial. All of them flow into a large axillary vein.
Elbow joint anatomy: lymphatic drainage (vessels and nodes)
The lymphatic system consists of vessels and ducts. Also in the body there are several groups of large peripheral nodes. Among them: axillary, ulnar, inguinal and other accumulations of lymphoid tissue. In addition, there are small nodes.
The outflow of lymph is carried out in deep vessels. They pass near the arteries and veins of the upper limb. Lymphatic vessels of the arm begin with the palmar network, pass along the bones and flow into the elbow nodes. Further, the outflow continues at shoulder level. Then the fluid collects in the axillary lymph nodes. After this, 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 how the forearm moves, 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 entities. They, in turn, are divided into small branches.
On the front side of the elbow are the radial and median nerve. The first - 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 posterior side of the forearm and half of the hand. The median nerve runs through almost the entire upper limb. Basically, it drives the flexor muscles of the palm and fingers, as well as the round pronator. The third major nerve is the ulnar. In the distal section, he passes into the palmar branch, which sets in motion 4 and 5 fingers. Its proximal part innervates the muscles of the forearm.
Anatomical features of the structure of the elbow in children
The anatomy of the elbow joint in children does not differ 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 the stretching of the arm in babies, a radial head of the radial bone occurs . Basically, this phenomenon is observed at the age of 1 to 3 years. And it is more common in girls.
How is the elbow joint in dogs
The anatomy of a dog’s elbow joint is similar to that of a human. This joint is problematic for animals and veterinarians. A characteristic of the elbow in dogs is the predisposition of articular tissue to dysplasia. This disease is common among many breeds. It refers to congenital malformations. With dysplasia, a gradual destruction of tissues occurs, as a result of which pathology leads the animal to lameness.