The spinal cord of a person is a complex mechanism that consists of many different "details". And each of them is important for our full life. It is precisely because we have the spine that we move. The reflex function of the spinal cord is one of the main ones that it performs. In addition to her, there is also a conductor. It is worth considering these functions in more detail and finding out what each of them is responsible for.
The formation of the spinal cord in the fetus occurs in the womb, and at that moment when she still does not suspect her pregnancy. By the end of the first month, the first foundation of the spinal column is laid. However, its full formation after the birth of the child will take some more time. Some parts of the brain will finally form when the baby is 2 years old.
What does the spinal cord look like?
Not everyone knows what the spinal cord looks like. Moreover, not all people have an idea of what its role is in the life of every person. In this regard, it is worth filling this gap in knowledge. In addition, many mistakenly believe that the brain and spinal cord are separate parts.
To find out what the necessary reflex function of the spinal cord is for, let's try to determine how it looks. It is impossible to clearly understand where the spinal cord begins and where it ends. It starts from the first vertebra just below the skull, smoothly connecting with the brain in this area. The division into the spinal cord and brain is formal, in reality, the spinal cord smoothly passes into the brain. Thus, we can conclude that these two parts are a single whole.
The location of the spinal cord and its membrane
The brain is protected by the cranial box, and the dorsal is hidden in the spine and surrounded by three membranes. The first of them is the most tender, thin and soft. It contains blood vessels that deliver nutrients to the brain. In other words, the spinal cord is a kind of "courier" for the delivery of food.
Continuing to talk about how the reflex function of the spinal cord works, it is impossible to ignore the analysis of the structure of the second cobweb of the membrane. There is a special space called subarachnoid. Along the entire length of the spine, it is filled with cerebrospinal fluid (cerebrospinal fluid). It is she who is taken during puncturing for analysis in order to determine the state of spinal cord operability.
The last shell is located outside and has a harder surface, which allows it to provide protective functions from various external damages.
Spinal cord characteristics
In adults, the spinal cord reaches 45 cm in length and 1.5 cm in thickness. Its weight, according to the most conservative standards, is no more than 35 grams. The whole brain is divided into several departments, from which various roots depart:
- cervical;
- thoracic;
- lumbar;
- cross
- coccygeal.
Since the reflex function of the spinal cord is carried out, the cervical and lumbosacral region are the most important parts of the spine. In this regard, they are best protected - nature itself took care of this, making them significantly thicker and denser. It is in these places that important nerve endings are located, the defeat of which threatens with serious consequences. In the cervical region there is a cluster of roots responsible for the movement of the hands. The roots of the lower section are responsible for the movement of the lower extremities.
The human spinal cord controls the activity of all internal organs. Each of them is associated with a specific department. In addition, the entire spinal canal is divided into segments and each of the listed departments has its own number. There are 8 in the cervical, 12 in the cervical, 5 in the lumbar and sacral, and there are one or two in the coccygeal.
What's inside?
To find out how the reflex and conductive function of the spinal cord is provided, take a look inside. The whole brain is not uniform in composition and color. In the very center is gray matter, which is surrounded on all sides by white. Each of them is responsible for certain functions, which will be discussed later.
Gray matter
The gray matter or substantia grisea is represented by several columns connected to each other by two plates (front and bottom), called adhesions. On a section of one of these pillars, one can see that the gray matter in its shape resembles a butterfly with spread wings or the Latin letter H.
In addition to this, one can also notice that protrusions, which are also called horns, depart from the substance. They can be either front ones located on the front wall or rear ones running along the back wall. Both the first and second paired, and have a narrow and wide shape. But in addition to the rear and front there are also side horns, in which the centers of the autonomic nervous system are enclosed.
What is the reflex function of the spinal cord? The fact is that in the front horns there is a special kind of motor neurons, the processes of which form the nerve roots.
In the middle of the gray matter passes the central channel, which is also filled with cerebrospinal fluid. In the upper part, the canal is connected to the ventricles of the brain. Moreover, all sections: ventricles, central canal and subarachnoid space take an active part in the circulation of cerebrospinal fluid.
White matter
White matter - substantia alba, envelops gray, is formed by a set of nerve fibers, which also come in three types:
At the same time, all the roots have a different direction, and some of them are directly connected with the brain and the central nervous system (hereinafter simply the central nervous system ). And if the reflex function of the spinal cord is to transmit signals of motor neurons of gray matter, then the task of white matter neurons is the prompt delivery of muscle and joint impulses to the medulla oblongata. Thus, the transfer of all commands along the entire spinal cord is realized.
Here are the ways by which all information regarding sensitivity and pain is transmitted. Only before entering the cerebral cortex, information first reaches the diencephalon, and only then rushes further to the destination.
The work of our brain
For the fast and correct operation of our body, ascending and descending paths are responsible. The last streams are formed using red and nuclear lateral paths. It is thanks to these paths that the reflex and conduction functions of the spinal cord are realized. Due to the rednuclear-spinal canal, involuntary motor impulses are produced. While for arbitrary impulses the lateral cortical-spinal pathways are responsible.
All roots are supplied with personal veins and arteries, which as a result forms neurovascular bundles. Each such bundle is responsible only for its segment and operates autonomously, analyzing the incoming information and transmitting the necessary pulses.
The defeat of these bundles leads to serious pathological and sometimes irreversible changes in the human body. And so that specialists can determine which particular beam was damaged and localize the pain, it is necessary to conduct a whole range of studies.
Reflex function
In our body, everything is thought out to the smallest detail, and our body reacts differently to every external stimulus. It is on reflexes that the defense mechanism is based. We sneeze, cough, get burns, start with a harsh sound, or react in our own way to gusts of wind. These are all examples of reflex function of the spinal cord and similar actions occur outside our control.
So that we can respond to any stimulus in a timely manner, including critical situations, pain receptors are located on the entire surface of our skin . As a vivid example: touching a hot kettle or any surface, we almost instantly pull our hand away. The reaction rate is so fast that it is impossible to understand the time frame. In a split second, a reflex ring is formed, which makes the muscles contract.
Another common case can be cited. It is worth accidentally swallowing a portion of smoke or pulling dust suspensions with your nose, sneezing or coughing will begin. Thus, it became clear that in such a short time information was received, processed and our “defenders” were instructed to free the body from the presence of foreign bodies.
Wire function
So, in what the reflex function of the spinal cord is expressed, it is now clear that we can move on to another, also significant task - the conductor. It consists in transmitting signals along ascending paths to the brain. From him, depending on the situation, the impulse along the descending paths is directed to some organ.
The wire function allows us to make meaningful actions:
- to take or toss;
- stand up or sit down;
- to go slowly or to run;
- draw;
- cut off.
We perform all these actions in everyday life: at home or at work, and usually just do not notice.
All this connection of the brain, spinal cord, the entire central nervous system, internal organs and all limbs makes the human body unique in nature. Even the most modern robot cannot boast of the number of movements that any bioorganism is capable of carrying out.