Читать книгу The Power Of Youth. How To Tune Our Mind And Body For A Long And Healthy Life - Андрей Фоменко - Страница 28

A total of 31 pairs of spinal nerves depart from the spinal cord – at the level of each vertebra. All spinal nerves contain sensory fibers, neuron projections that collect information from tactile, pain, temperature receptors of the skin, etc., and send it for "processing" to the central nervous system. They also contain motor fibers through which impulses from the brain and spinal cord travel to the muscles, making them contract.

As they move away from the spinal cord, the roots begin to branch, forming nerve trunks, large nerves, and then dividing into smaller ones. Each nerve ends with a nerve ending near a specific body part. All nerves divide into motor, sensory, and mixed (containing both types of projections) ones.

A separate group consists of 12 pairs of cranial nerves. The bodies of neurons, which projections form the cranial nerves, are part of the special clusters of gray matter, the nuclei of the brain stem. They go beyond the periphery from openings in the skull, and the areas they "work with" do not extend beyond the head and neck. The only exception is the vagus nerve, which plays a crucial role in regulating the work of internal organs.

The peripheral nervous system is divided into autonomic and somatic. The somatic nervous system regulates the functioning of the skeletal muscles, which are responsible for movements that we consciously control. The autonomic nervous system regulates the living environment, which is beyond our consciousness. These include breathing, heartbeat, sweating, etc.

For example, when we face any danger, the autonomic nervous system first activates: the pulse and breath quicken, cold sweat appears, and the muscles turn rigid. All these reactions are unconscious. And then the somatic nervous system comes into play: we decide "fight or flight" by giving the appropriate orders to our skeletal muscles.

In turn, the autonomic nervous system is divided into sympathetic and parasympathetic. The sympathetic nervous system is responsible for processes occurring in the waking state. The sympathetic nervous system manages the mechanisms allowing the body to maintain a tone and respond quickly to stressful situations. The parasympathetic system, on the contrary, regulates the processes occurring during rest and sleep: the heart rate slows down, breathing becomes rare, and vessels expand, but digestion, on the contrary, occurs more intensively.

Thus, the nervous system is a complex structure with multilevel regulation, which is carried out at both conscious and unconscious levels. Understanding the principles of the structure and functioning of the nervous system, and knowledge of buttons that we can push through our thoughts, actions, and lifestyle, are essential to preserving health and increasing life expectancy. Before you learn to "negotiate" with your nervous system, you need to understand the "language spoken" by neurons. Such "language" is a special molecule called a neurotransmitter.