Of all the body's nervous system is the most important.That depends on it coordinated work of all other organs, tissues and cells.The main significance of the nervous system to the body that at its expense, it functions as a whole.In addition, it also monitors the body contacts with the external environment.
man by the system can think, analyze events.The deep significance of the nervous system to the body is more important: it controls all the processes including respiration, blood, hunger and thirst, it is also responsible for all of our reflexes, including the most primitive.To understand its importance for our body's with you, you should know (or at least at a primitive level) its structure.
What is a part of the nervous system?
Founded she nervous tissue, which consists of neurons and satellite cells (astrocytes).Let us briefly describe their purpose:
- Neuron - the main functional unit of the nervous tissue.These cells are responsible for the thinking, and for all other functions of the entire system.
- cells operate satellites and trophic support function.Currently, it is believed that they do also play an important role in the mechanism of long-term memory, but this hypothesis needs to be clarified.
continue to discuss the structure and value of the nervous system.
structure of the neuron
This cell, which is responsible for almost everything that happens in the body, is composed of body and appendages.They are divided into two types: axons and dendrites.The first of them depart from the cells in a single copy, long.On the contrary, dendrites differ not too prominent size, highly branched.Typically, each of the nerve cell may be several.According to the dendrites of nerve impulses going into the cage.
axon differs great length, little branches.As it pulses out of the body of the nerve cell.The length of this process can exceed several tens of centimeters.According to it the signals are transmitted by means of electric discharges almost instantaneously.
small digression.It should be noted that the value, structure and functioning of the nervous system is so complex and diverse that many of the functional features of some particularly complex biochemical processes that occur in the depth of the central nervous system, scientists are just beginning to guess.
axons coated from a fat-like substance, which serves as an insulator.It processes these clusters form a white solid of the nervous system.The body of the neuron and dendrites have no shell.Accumulations of these objects are called gray matter.
continue to explore the structure and value of the nervous system.You must have a clear idea that neurons are largely differentiated, universal cell of this type does not happen.We continue to talk about the importance of the nervous system.The general plan of the nervous system it is impossible to imagine even approximately, if you do not know the structure of the neuron, its functional units.
What are neurons?
Do not assume that all are the same neurons.On the contrary, they are very different from each other in form and functions.Sensitive transmit impulses from the sense organs to the brain.Their bodies are located in major ganglia of the body.By the way speaking, the so-called large clusters of neurons outside the brain and spinal cord.Motor species, by contrast, transmits impulses from the brain to the muscles and internal organs.
intercalary neurons are responsible for the communication and transfer of information between sensory and motor cells.These processes are very short, playing the role of "layers" does not extend beyond the brain.Thus, the brain receives information from all body systems and organs.
So, the interim results.What is the main significance of the nervous system to the body?We list:
- It receives signals from the senses, smell and touch receptors.
- In neurons analyzed the information received.
- On executive body (muscle, for example) corresponding to the transmitted pulse.
- body adequately respond to irritating environmental factors.
Impulses from the brain and transmitted to it, not only for individual spikes of neurons, but also by specialized nerves.
What nerves?
In everyday life, we hear this word, but its true meaning is somehow not think.But the nervous system and its role in the body are so great that you should know about this!
Nerves called as time accumulation of long processes of neurons, which are covered with a special protective coating.If by this "winding" are processes of motor neurons, the nerves themselves are called motor.Typically, nerve trunks contains both dendrites and axons.In this case they are called mixed.They differ in that they can transmit nerve impulses in both directions.
Departments
nervous system has two main divisions: the internal and peripheral.The Central Division includes the brain and spinal cord is protected by the bones of the skull and spine.Accordingly, the periphery includes nerves and ganglia neurons separate processes.
That part of the nervous system that controls the operation of skeletal muscle, called somatic.Thus, the importance of the nervous system to the body in this case is extremely important: it is the "somatic" allows us to move his arms and legs.In the internal organs responsible autonomous systems department.Its functioning is not subject to conscious human will.Simply put, you are unlikely to know how to manage the process of digestion, slow down or accelerate it.
Thus, the importance of the nervous system in the regulation of body functions is very large: it controls, even those processes that most people do not even know.Of course, if their body is all right and everything works in "normal" mode.
In this section there are two major "structural unit": the sympathetic and parasympathetic nervous system.Almost all the internal organs are innervated by nerve trunk was from her.Effect on the body at diametrically opposite these parts.
For example, increases of sympathetic cardiac striated muscle, and parasimpatika - slows down the process, it is responsible for digestion.Thus, the role of the parasympathetic nervous system in the body is even more important.It is responsible for respiration and other vital processes.
Reflex
And what is the significance of the nervous system in a completely unconditional response of humans and animals to some irritation of the environment?Simply put, how the reflex activity?
As you know, is responsible for this mechanism, which we know as the "reflex arc."This is the path along which the nerve impulses in the moment when the body responds to stimulation of the reflex.It consists of the following sections: a receptor responsive way of a charge of the reflex portion of the nervous system, the path along which the signal, as well as the working member.
That's how important the nervous system in human life.When there is something broken, to a sick person can be a real feat of self-tying shoelaces.It is surprising how little many are thinking about the importance of the nervous tissue!
about the length of the reflex arc
Each arc begins with sensory receptors.Each of them sees only some certain kind of stimulus.The receptors are responsible for the conversion of effects of the environment into nerve impulses.The impulses that move the skeletal muscles, triggering some important processes and perform an equally important function are purely electrical in nature.Using a sensitive neuron pulses transmitted to the central nervous system.
We note that almost all reflex arcs are composed of intercalated neurones.
Many believe that reflex reaction - completely unconscious process that, once entrenched, remains completely unchanged.But this is not so.The fact that the signal received from the receptor, the nervous system is not only accepted but holds its analysis evaluating the efficacy of the reaction.Simply put, it is because people in the training brought their actions not only to reflex automatism, but also make it perfect.
And now let's talk, what is the significance of the nervous system in the context of the discussion of the spinal cord.Some believe that it is exclusively for the transmission of impulses from the brain to the underlying divisions.Blunders, as part of the body is much more important.
structure of the spinal cord
Located spinal cord in the spinal canal.Limited and protected natural cavities - cranial bones, as well as by the spinal column.Theoretical (anatomical), the boundary between the spinal cord and brain passes between the occipital bone and the atlas.
The man has the form of white cord, Diameter of approximately 1 centimeter.Channel itself is filled with liquor, cerebrospinal fluid.On the surface of the body are two deep longitudinal grooves that divide it into right and left sides.If the brain is cut in half, you can see quite a nice pattern that resembles a butterfly.
Her body formed neurons (intercalary and motor).As we have already said, the white substance that covers them on all sides, is a long processes of neurons.They extend along the spinal cord up and down to form uplink and downlink channels.
What does the spinal cord?
is charged with two main tasks: the reflexes and the role of conductor paths.Due the reflex function we are able to make a lot of movement.All the contraction of skeletal muscles of the body (except the muscles of the head) one way or another connected with the reflex arcs, which is directly dependent on the activity of the spinal cord.
other words, the role of the nervous system in a living organism is very versatile: in the regulation of the organs and systems are sometimes involved her department, which many remember very rarely.
We do not exaggerate!After the spinal cord in the company with his "head counterpart" regulate the correct operation of the incredible number of organs: digestive system and heart, urinary system and reproductive organs.Due to the white matter of synchronized, full-stage provided their response to external and internal stimuli.
Important!Do not forget that the spinal cord is still subject to the head around.It is not uncommon as a result of injury, accident or illness in humans is completely interrupted the connection between the brain and spinal cord.First, in such cases it works perfectly fine.Here are almost all reflexes, which are located below the zone, completely disappear.
Such people can, at best, to move his arms, turn his head slightly, but the entire lower part of the body they completely motionless and devoid of any kind was a sensation.
brain
located in the skull.It is subdivided into the following departments: the medulla oblongata, cerebellum, bridge, intermediate and middle part, and the hemisphere.As in the previous case, it has white and gray matter.White connects both parts of the brain and the spinal his department.Because of this, all CNS functions as a whole.
In contrast to the spinal cord, there is gray matter comes to the surface of the body, forming its bark, cortex.
medulla oblongata is in fact a continuation of the spinal card and is required for the connection of these parts of the nervous system together.He is responsible for breathing, digestion and other unconscious functions, but because of his fatal injury for life.
value of the individual components
cerebellum controls motor functions.The midbrain is a "transit point" for many reflex arcs.Medulla, pons and midbrain form a kind of trunk linking between different departments and perform many reflex functions.Cora - the youngest and the most important department.It is due to it, we think, thoughts, we keep our memories.Injury cortex is fraught with complete loss of identity.
many cases where people stay long in a state of clinical death, drowned, after a particularly terrible accident, appeared live as a result of intensive and cardiac resuscitation.That's just such a state of life is extremely difficult to call.Cortical neurons die very quickly, after which the person turns into a "vegetable".He can not say he has no memory of the previous life (with rare exceptions), it generally can not take care of themselves.
Here how important the nervous system in the life of the organism.
