What is part of the nervous system. Anatomy of the Human Central Nervous System - Information. Which doctors should I contact for examining the Central Nervous System

As we devote ourselves to the construction and functioning of the nervous system in other parts, we are limited to simply adding neural tissue to the tissue list. human body... The ability to receive and respond to external information is already developed in unicellular organisms. In the case of multicellular organisms, a specialized sensory information system is involved in receiving information. Then the information is processed, integrated and further transformed into a specialized nervous system.

In the next section, we describe the basic units of the nervous system. They are found in all types of nervous systems that we encounter in the animal kingdom. In the most primitive types of nervous systems, synapses are not polarized, and neurons are not dendritic and axonic — neurons and synapses can propagate in both directions.

It consists of a network of synaptically connected nerve cells that pass through the body and do not form clusters or centers. There are two parts: central and peripheral nervous system... Nerve fibers differentiate into dendrites and axons - they allow one-way guidance. We call the leading information flow to the center afferent. The fibers that carry information from the center are designated as efferent.

The nervous system of the ganglion has its centers, formed by clusters of nerve cells - nerve ganglia. The largest ganglion in the head is called the cerebral ganglion. One or more nerve strips are removed from it, where we find other nerve ganglia, marked next to the organs.

The ganglionic nervous system is found in pubes, insects, and primitive molluscs. Some differences in design are found in the nervous system of the cephalopods - for example, a significant accumulation of brain neurons in the ganglia, and another feature of the cephalopods is the developmental chamber of the eye.

The process of cephalization increases the volume of the cerebral ganglia, thereby occupying the central role of the brain and gradually creating the brain. The developed centralized nervous system contains the brain, spinal cord and autonomic, motor and sensory peripheral nerves, which, together with the network of peripheral nerve ganglia, are sensitive and autonomous from the peripheral nervous system.

Although the specialization of the nervous system brings maximum benefits to its owners for their lifestyle, highly developed brains are found in mammals. The final development of the brain then boasts a human being. The topic of the human brain occupies the next part of this module.

The nervous system is at the top of the imaginary list of the organism's regulatory hierarchy - it provides coordination, synergy and functionality of the entire organism. It works, of course, in indissoluble unity with the whole organism, and not as an isolated system!

The structure, function, capacity, regulation and functioning of the nervous system are extremely complex. The significance and role of the nervous system is reflected in all areas of human existence. Based on the material, the nervous system is a substrate or correlation or carrier matrix of all human mental activity. This is why, in modules focused on the area of ​​consciousness, it also makes sense and is important to deal with the construction and functioning of the nervous system.

Neurosciences, who are concerned with the construction, functioning, but also with disorders, diagnosis and treatment of the nervous system, are fast developing area... They include both theoretical and practical application areas. In this module, we will focus on basic knowledge of the construction and physiological functions of nerve cells, the nervous system.

Helper cells are counted several times over nerve cells. They have functions, support, construction, protection, elimination of waste and damaged neurons. After neuronal necrosis, a glial scar is formed. They form bundles of nerve fibers and isolate individual synapses. They also affect the number of functional synapses and neuronal function. They are involved in immune surveillance and help maintain homeostasis.

In the brain and spinal cord we find: astrocytes, oligodendroglia, microglia and ependymal cells. Outside the brain and spinal cord: Schwann cells and satellite cells. ... Nerve cells - neurons - highly specialized cells. They are linked to each other and to other cells. Together they create a complex spatial network of interacting elements. Thanks to electrical potentials and chemicals, neurons divide, transmit, change and generate information flows.

There are several different types of neurons. The estimated total number of neurons in the human brain is in the hundreds of billions. The number of interactions between them is then a thousand times greater. Individual neurons vary greatly in shape, size, specific function, metabolism, and the chemicals they contain and produce. The basic structure of all neurons is the same. Each neuron contains a cell body and a system of protrusions.

Perhaps in a similar way, since different varieties of trees differ in their crowns, different types neurons differ in the range, density, or length of their dendrites. An essential feature of all dendrites is that information in the form of electrical impulses always leads to the nucleus of the neuron - centripetal. Unlike most rich dendritic branches, the axon usually reaches the end. Its initial compartment is removed from the so-called axon hump on the body of the neuron. ... In terms of neural function, we distinguish between sensory, motor, plant, and interconnected neurons.

Sensory neurons carry sensory information to the central nervous system. Autonomic neurons control all internal organs and tissues of the body, which are not subject to free testing. Autonomous neurons are connected and efferent. Connective neurons - interneurons have interrelated and integrative functions. We find them in a large number, especially in the brain and spinal cord.

• They are afferent - they store information from the periphery to the center.
• Motor neurons control skeletal muscle.
• They work quickly - from the center to the periphery.
• They allow you to move freely.

The cells from which they are derived are called neuroblasts. During their differentiation, only certain genes are activated, while others remain inactive. Ripe human neurons lose their ability to reproduce. However, stem cells retain the ability to divide and differentiate in mature neurons. Even in adulthood, there is some potential for neuronal repair.

Neurons can disappear in two ways. Nerve cells can be gray or white. The gray nerve fibers are the protrusions of the naked nerve cells. White nerve fibers are protrusions of neurons covered with myelin sheaths.

In the mammalian nervous system, membranes are created by two types of supporting cells - oligodendroglia in the central nervous system and Schwann cells in the peripheral nervous system. The myelin sheath is interrupted at regular intervals by Ranvier incisions - free spaces between two supporting cells. Ravenier is about 1 micron wide.

With grayish nerve fibers, individual nerve extensions spread continuously - continuously. White nerve fibers spread from one rabbi to another - saliva. Information management using nerve fibers. Nerve fibers can carry electrical impulses at different speeds.

While type A and B fibers are myelinated, type C fibers are bare. The myelin sheaths are used to isolate individual nerve fibers. At the same time, they increase the speed of electrical impulses - the speed of movement is directly proportional to the distance between two adjacent Ravier slots.

When it comes to short cell organelles, neurons are no different from other cells in the human body. The plasma membrane is a very active cell. It constantly changes its structure, restores and transforms the parts that make it up. This is the site of many active stories.

Transmembrane transporters, according to their name, transport ions from the cytoplasm to external environment and vice versa. Their activity requires energy. It is with this splitting that the energy that the diaphragm pump uses is released. As a result of the action of transmembrane transporters, there is an uneven distribution of ions inside and outside the cell.

Sodium and potassium ions are not the only ions we encounter. However, the role of the membrane potential is critical. This is why we deal with them in the first place. But let's not forget that calcium, chloride, and other ions also have an impact.

Uneven concentrations of ions inside and outside the cell create concentration gradients. They move logically from a site with a higher concentration to a lower ion concentration. Concentration gradients are the driving force behind the penetration of membrane potentials.

Illustratively, we can illustrate the direction of the sodium concentration gradient. The direction of the concentration gradient for potassium is opposite. Potassium passes through the plasma membrane quite easily. For sodium, on the other hand, the plasma membrane is almost impenetrable at rest. Following the direction of its concentration gradient, potassium leaves the cell and carries a positive charge. This creates the resting potential of the membrane - outer side membrane is charged positively, and inner side negative.

Clear polarization of the plasma membrane. Adequate irritation of the cell membrane can cause a change in the membrane potential - receptor or action potential. The receptor potential reaches different amplitudes and does not spread from the place of origin.

Potential potential is initiated only by a stimulus of a certain intensity. During it, significant changes in ion fluxes and membrane polarization occur. The action potential from its place of origin spreads along the plasma membrane.

The course of the action potential is always identical and consists of the phases of depolarization, repolarization and hyperpolarization. Depolarization - due to the opening of fast sodium channels. Due to the massive influx of positive sodium ions into the cell, electrical charge is first established inside and inside the cell, and the polarity of the membrane changes direction when the inside of the membrane is charged positively and the outside is negative.