Human musculoskeletal system
The support and locomotor system is an organ system in the anatomy. It ensures that the body remains in a fixed form, but can still be moved purposefully. For that he is composed of fixed and movable organs.
The bony skeleton provides for the shaping of the body. It is moved through the skeletal muscles. These tendons serve as a force transmitter, which are grown on one side of the bone, are anchored on the other side in the muscle. If it is necessary to change the direction of pull of the tendon, they are deflected with ribbons. Bands also serve to consolidate heavily loaded joints and secure.
The term " brace " orthoses are referred to in orthopedics, which are applied in functional impairment of the musculoskeletal system.
The skeleton consists of differently shaped bones ( long bones, bone plate and others) that are fused together in part, such as the skull or the pelvis. It not only has the task to ensure the shape of the body and thus ensure the mobility of the organism, but has also to enable protection for internal organs (again, skull and pelvis) or their work in the first place ( the chest, without the breathing not might work ). In addition, the interior of the bone, the bone marrow, an important training center for the blood cells.
The bones are interconnected by joints, which determine the movement direction and range of motion of the bones.
The skeletal muscles connect two different bones by schedule at least one joint away with their tendons to the bone. When a muscle shortens, it pulls the two bones in the joint to another. Muscles only have the ability to contract, but not to stretch themselves in their initial position. They need one or more muscles which are attached on the other side of the joint and cause the opposite movement. Such muscles opponent (Latin: antagonists) mentioned.
Skeletal muscles do not have to be grown necessarily only at a single point on a bone. Some muscles are divided into two or more parts, although they start on one side in a common tendon, ends on the other side but at different locations on the same or even different bones. Such muscles are called biceps (with two muscle heads ), triceps ( three heads ) or quadriceps ( four muscle heads).
Skeletal muscles are composed of individual cells ( muscle fibers). More of these muscle fibers constitute muscle fiber bundle, several of which are combined with a solid net-like skin, fascia, and together form the surrounding muscle.
Tendons and tendon sheaths
Thus, the force developed by the muscles is converted into motion of the bones, both modules must be connected together. This is the task of the tendons. They are made of strong but flexible collagenous connective tissue. Their fibers are parallel to the direction of pull. Tendons are fused in the muscle with the muscle fibers and put the bone in on projections or roughened areas.
In addition to the "normal" Tendons are also tendons plates ( Medical: aponeuroses ). You do not have the form of a cable, but a solid, thick skin. In them several muscles or muscle heads together can begin (eg Zungenaponeurose, aponeurosis linguae ).
In order to spare the tendons unnecessary friction that they can damage, particularly long tendons are performed in tendon sheaths. This is to tubes of two skin layers, between which fluid ( synovial fluid ) is located. This creates a sliding surface, which considerably reduces the friction between the tendon and the surrounding tissue.
Even bands ( Latin: ligaments, ligament sing. ) are usually made of collagen fibers, rare but also of elastic connective tissue. They are located either around joints or in them (for example, the cruciate ligaments of the knee joint ). Support the joints or inhibit the mobility of the bones to each other, thereby helping to avoid over-stretching of muscles or tendons.
Also in the abdominal cavity, there are bands that keep organs in place. You have nothing to do with the bands of the musculoskeletal system and were in the outdated Jena Nomina Anatomica (JNA ) is called the notochord or plica; occasionally we find this name yet in the literature.
At locations that pose a particular risk for tendon, the body builds extra padding, which are intended to protect the tendon against chafing: the bursa (Latin: Bursa synovial ). These pads are small skin pillows that are filled with a liquid and are placed under the tendon on the endangered side. By the liquid pressure of the tendon is distributed evenly over a larger area.
A sesamoid bone is a small bone that has grown into a tendon and ensures additional distance to the bone. This results in a greater lever for the tendon, so that less force is needed to move the tendon is connected to the bone.
The best-known example of a sesamoid bone is the patella, which is embedded in the tendon of the quadriceps femoris. By this construction, the leg can be readily extended without the need to have more or thigh muscle.
- Support and movement apparatus