Central nervous system

The central nervous system includes the spinal cord and the brain. The first looks like a slightly flattened back of the stitch. And the brain, located in the cavity of the skull, consists of two hemispheres, a trunk and a cerebellum.

The physiology of the central nervous system controls the relationships between the body and the environment, the reactions of the person to various stimuli. Also thanks to her coordination of organs and parts of the body. In general, its activity is based on reflexes, because the body reacts to the slightest changes in its environment or in its internal environment.

The central nervous system conducts nervous connections with the body as a whole through cranial nerves (12 pairs thereof) and spinal roots (their 31 pairs). From the muscles, skin, partially limbs and internal organs, "information" to the spinal cord is transmitted through the afferent nerves coming from the posterior roots. And the "information" from the skeletal muscles comes to him through the efferent nerves coming from the back roots. The presence or absence of reflexes indicates how the spinal cord works, does it perform a reflex function. Its damage entails a violation of the transmission of all impulses (both afferent and efferent). From the spinal cord to the brain and back are the nerve pathways that pass necessarily through the entire brain stem, in which they are partially interrupted or terminated. The oculomotor, auditory and optic nerves are laid in the middle brain. Management of metabolism, circulation, nutrition occurs in the diencephalon through the connection of perceptions (internal and external) with the work of the endocrine and cardiovascular system. The cerebral cortex includes a huge number of neurons. They are cells of different shapes, which are arranged in several layers and are joined together by means of processes. Each section of the cortex has a different composition of cells, this is due to the function that it performs.

The entire central nervous system, all its departments in every act of human behavior work as one whole, thus forming a functional system. From the position of this understanding it is obvious that any reaction, any reflex, is preceded by considerable work. At any given time, the central nervous system depends on the needs of the body. First of all, they are motivated by an objective premise - a change in the environment within the body. From the point of view of neurophysiology, this mechanism occurs by activating the cortex of the cerebral hemispheres through the subcortical centers. They send those impulses, which the organism most of all needs at the moment. The central nervous system seeks to satisfy the dominant motivation. To this end, it synthesizes all available information about the state of the external and internal environment of the organism, and then realizes the behavioral act.

The defeat of the central nervous system occurs for many reasons. These are congenital malformations, and circulatory disorders, the impact of trauma, the effect of tumor or inflammatory processes. The brain and spinal cord develop with defects if the fetus is affected by the following dangerous factors: the transfer of infectious diseases during pregnancy, injury, radiation exposure, exposure to toxic substances, alcoholism of both parents or one of them. Not the least role in the appearance of deviations is played by heredity.

Particularly severe malformations occur when the factors listed above affect the fetus in the initial months of pregnancy. Among them, the first place is occupied by hydrocephalus (in the brain ventricles too much cerebrospinal fluid accumulates ) and microcephaly (underdeveloped brain and skull). Affect the defeat of this system and the developmental defects of the spine and bones of the skull.