The skeleton, the photo of which will be presented below, is a collection of bone elements of the body. The word itself has ancient Greek roots. Translated, the term means "dried". The skeleton is considered the passive part of the musculoskeletal system. It develops from the mesenchyme. Next, let's take a closer look at the skeleton: structure, functions, etc.
Gender Features
Before talking about what functions the skeleton performs, a number of distinctive features of this part of the body should be noted. In particular, some sexual features of the structure are of interest. In total, there are 206 bones that make up the skeleton (the photo illustrates all its elements). Almost all are connected into a single whole through joints, ligaments and other joints. The structure of the skeleton of men and women is generally the same. There are no cardinal differences between them. However, differences are found only in slightly changed forms or sizes of individual elements and systems that they make up. The most obvious differences that the structure of the skeleton of men and women has include, for example,that the bones of the fingers and limbs of the former are somewhat longer and thicker than those of the latter. At the same time, tuberosities (areas of fixation of muscle fibers) are, as a rule, more pronounced in men. In women, the pelvis is wider, and the chest is narrower. As for the sex differences in the skull, they are also insignificant. In this regard, it is often quite difficult for specialists to determine to whom it belongs: a woman or a man. At the same time, in the latter, the superciliary ridges and tubercle protrude more strongly, the eye sockets are larger, and the paranasal sinuses are better expressed. In the male skull, the bone elements are somewhat thicker than in the female. The anteroposterior (longitudinal) and vertical parameters of this part of the skeleton are larger in men. The capacity of the female skull is about 1300 cm3. For men, this figure is also higher - 1450 cm3. This difference is due to the smaller overall size of the female body.
Headquarters
There are two zones in the skeleton. In particular, it contains the trunk and head sections. The latter, in turn, includes the front and brain parts. The brain part contains 2 temporal, 2 parietal, frontal, occipital and partially ethmoid bones. As part of the facial section there is an upper jaw (steam room) and a lower one. Teeth are fixed in their sockets.
Spine
In this department, coccygeal (4-5 pieces), sacral (5), lumbar (5), thoracic (12) and cervical (7) segments are distinguished. The vertebral arches form the spinal canal. The pole itself has four bends. Thanks to this, it is possibleimplementation of the indirect function of the skeleton associated with bipedalism. Between the vertebrae are elastic plates. They improve the flexibility of the spine. The appearance of the bends of the column is due to the need to soften shocks during movement: running, walking, jumping. Thanks to this, the spinal cord and internal organs are not subjected to concussion. A canal runs through the spine. It surrounds the spinal cord.
Chest
It includes the sternum, 12 segments of the second spine, and 12 rib pairs. The first 10 of them are connected to the sternum by cartilage, the last two do not have articulations with it. Thanks to the chest, it is possible to perform the protective function of the skeleton. In particular, it ensures the safety of the heart and organs of the bronchopulmonary and partially digestive systems. Behind the costal plates have a movable articulation with the vertebrae, in front (except for the lower two pairs) they are connected to the sternum through flexible cartilage. Due to this, the chest can narrow or expand when breathing.
Upper limbs
This part contains the humerus, forearm (ulna and radius), wrist, five metacarpal segments and digital phalanges. In general, three sections are distinguished in the skeleton of the hand. These include the hand, forearm and shoulder. The latter is formed by a long bone. The hand is connected to the forearm and consists of small carpal elements, a metacarpus that forms the palm, and movable flexible fingers. Attachment of the upper limbs to the body is carried out by means ofclavicles and shoulder blades. They form the shoulder girdle.
Lower limbs
In this part of the skeleton, 2 pelvic bones are isolated. Each of them includes ischial, pubic and iliac elements fused with each other. The hip is also referred to the belt of the lower extremities. It is formed by the corresponding (eponymous) bone. This element is considered the largest of all in the skeleton. Also, a shin is distinguished in the leg. The composition of this department includes two tibia - large and small. Hangs the lower limb of the foot. It consists of several bones, the largest of which is the calcaneus. The articulation with the body is carried out by means of the pelvic elements. In humans, these bones are more massive and wider than in animals. Joints act as connecting elements of the limbs.
Joint types
There are only three of them. In the skeleton, the bones can be connected movably, semi-movably or immovably. Articulation according to the latter type is characteristic of cranial elements (except for the lower jaw). The ribs are semi-movably connected to the sternum and the vertebrae. Ligaments and cartilage act as articulation elements. The movable connection is characteristic of the joints. Each of them has a surface, a liquid present in the cavity, and a bag. As a rule, joints are strengthened by ligaments. Due to them, the range of motion is limited. The joint fluid reduces the friction of the bone elements during movement.
What is the function of the skeleton?
This part of the body has two tasks: biological and mechanical. In connection withsolving the last problem, the following functions of the human skeleton are distinguished:
- Motive. This task is performed indirectly, since the elements of the skeleton serve to attach muscle fibers.
- The support function of the skeleton. Bone elements and their joints make up the skeleton. Organs and soft tissues are attached to it.
- Spring. Due to the presence of articular cartilage and a number of structural features (curves of the spine, arch of the foot), depreciation is carried out. As a result, shocks are eliminated and shocks are softened.
- Protective. The skeleton contains bone formations, due to which the safety of important organs is ensured. In particular, the skull protects the brain, the sternum protects the heart, lungs and some other organs, the spine protects the spinal structure.
Biological functions of the human skeleton:
- Hematopoietic. Bone marrow is located in the bones. It acts as a source of blood cells.
- Reserve. Bone elements serve as a depot for a large number of inorganic substances. These include, in particular, iron, magnesium, calcium, phosphorus. In this regard, the bones are involved in maintaining a stable mineral composition within the body.
Damage
In case of incorrect body position for a long period (for example, prolonged sitting with the head tilted at the table, uncomfortable posture, etc.), as well as against the background of a number of hereditary causes (especially in combination with nutritional errors, insufficient physicaldevelopment) there may be a violation of the holding function of the skeleton. In the early stages, this phenomenon can be eliminated fairly quickly. However, it is better to prevent it. To do this, experts recommend choosing a comfortable posture when working, regularly doing sports, gymnastics, swimming and other activities.
Another fairly common pathological condition is foot deformity. Against the background of this phenomenon, a violation of the motor function of the skeleton occurs. Foot deformity can occur under the influence of diseases, be the result of injuries or prolonged overload of the foot in the process of body growth.
Under the influence of strong physical exertion, a bone fracture can occur. This type of injury can be closed or open (with a wound). About 3/4 of all fractures occur in the arms and legs. The main symptom of injury is severe pain. A fracture can provoke a subsequent deformation of the bone, a violation of the functions of the department in which it is located. If a fracture is suspected, the victim must be provided with an ambulance and hospitalized. Before taking any action, the patient is sent for an X-ray examination. During the diagnosis, the site of the fracture location, the presence and displacement of bone fragments are revealed.
