The value of the skeleton for a person. Features of the skeleton
The musculoskeletal system performs in the bodythe most important functions. It is the movement of the body in space and the maintenance of its shape, the protection of internal organs from mechanical damage, and also their maintenance in a certain position. The value of the skeleton for a person is also great. This is the basis, without which support and movement is impossible.
Biology: the skeleton and features of its structure
The basis of the musculoskeletal system isthe totality of bones is the skeleton. In humans, it consists of several parts: the skull, trunk, belts and their free limbs. The structure of their components is due to the vertical arrangement of the organism in space. Let us consider them in more detail.
Methods of connecting bones
Depending on the functions performed, the bonesunite in different ways. A fixed connection is called a seam. In this way all the bones of the skull are connected. In a newborn baby, the parietal bone of the skull consists of cartilaginous tissue, which eventually is replaced by bone. This is necessary in order for the fetus to pass through the narrow enough female reproductive tract at birth. Thanks to this structure, the skull is able to change its volume.
With the help of a semi-mobile connection,bones of the human spine. Between them are cartilaginous layers, capable of compression and stretching. Therefore, the mobility of the spine is limited. This structure has its advantages: the cartilaginous tissue softens the tremors during sharp movements.
Movable joints of bones are called joints. The main value of the skeleton for a person is to provide motor activity. This function is provided by them. Each joint consists of two heads covered with cartilage. Outside, this structure is additionally protected by an articular bag, to which ligaments and muscles are attached. It also releases into the cavity a special fluid that reduces the friction process.
The elbow joint is able to move only in onedirection, knee - in two. This is the attribute underlying their classification. Depending on the number of directions of motion, one, two, three-axis joints are distinguished. An example of the latter is the hip.
Skull
The skeleton of the head is represented by immobile bones. And only the lower jaw is capable of movement, due to which we absorb food and talk.
Another meaning of the skeleton for a person is protection. Skull bones protect the brain from mechanical damage.
This part of the human skeleton consists of two parts: facial and cerebral. They, in turn, consist of paired and single bones. For example, the largest components of the facial section are the zygomatic and maxillary. In total, their total number totals 15 bones. The cerebral cortex is connected through the opening in the occipital part to the spinal canal. As a result, the anatomical interrelation of the brain and spinal cord becomes possible, which is a necessary condition for the normal functioning of the nervous regulation of the human body.
Skeleton of the trunk
It is represented by the spine and thorax. The skeleton of the trunk serves as the basis to which belts and free limbs are attached.
Each vertebra consists of a body and processes,except the first of them. It is called "atlant" and consists of just two arcs. To him, his dentate process is attached an epistrophe - the second one. This structure ensures the rotation of the human head. In general, this part of the skeleton consists of 33-34 vertebrae, forming a channel in the cavity of which is the spinal cord.
The structure of the chest justifies itsname. It protects internal organs from shock and deformation. It consists of a flat bone of the sternum, 12 pairs of ribs, which are attached to the thoracic spine.
Skeleton of belts
Why wear a belt? To keep clothes. So everyone will answer. Similarly, the limb belt, which provides an important skeleton. Man can not be imagined without movement. Bones of free extremities are attached to the bones of the belts.
Upper - clavicle and scapula. Belts of the upper extremities include pelvic and sacral bones. The first form a semi-joint, called pubic adhesion. Sacrum consists of 5 bones, fused into one.
Upper free limbs
Consist of 3 parts: shoulder, forearm and hand. They are connected together, forming joints. The humerus is attached to the shoulder blade. The forearm is formed immediately by two bones: the elbow and the ray. In the hand, in turn, the wrist, the pastern and the phalanges of the fingers are distinguished.
Lower free limbs
In this part, the hip, shin and foot are selected. Their structure is similar to the upper limbs. To the bones of the pelvis is attached the femur - the longest in the human body. The shin consists of a large and small tibia. A stop - from the tarsus, metatarsus and phalanges of fingers.
Skeleton and right ascension
What is the significance of the skeleton for a person and his life activity, we found out. But there is one more important aspect. All features of the human skeleton are related to its horizontal position in space.
The table "The human skeleton and features of its structure in connection with the upright" clearly demonstrates this.
| Part of the skeleton | Features of the structure |
| Skull | The brain is more developed than the facial part. |
| Rib cage | Flattened in the dorso-ventral direction, widened laterally. |
| Spine | Forms several bends that soften the shocks during the movement and act as shock absorbers when walking. |
| Upper limbs | The thumb of the hand is opposed to the rest, which is due to the person's ability to work. |
| Lower limbs | Pelvic bones widened, forming a kind of bowl, helping to keep the body in a horizontal position. The foot is vaulted, the structure of which makes it easier to push when walking, jumping and running. |
Reduction of the facial part of the skull is associated with an increase in the volume of the human brain. Its development was influenced by the development of speech and abstract thinking.
Anthropology is the science of the origin of man,argues that it is the result of evolutionary processes. One of their driving factors is natural selection. Its essence lies in the fact that as a result, individuals who could produce and operate simple tools could survive. This is possible only under the condition of a special structure of the brush. The thorax in animals is extended downwards. Moving on two legs to such organisms is quite difficult.
Thus, the human skeleton has all the features necessary for spinning, providing the ability to change the position of individual parts and the entire body in space.
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