المراكز الرئيسة في الجملة العصبية

المراكز الرئيسة

في الجملة العصبية


The spinal cord - 1 Functions of the spinal cord is composed of a series of nerve centers that issue reflexes. The reflex action is the automatic action that follows an external stimulus. Therefore, if you cut off the connection between the spinal cord and the external stimuli, the spinal cord will refrain from issuing its reflex actions. If you cut the upper part of it, the intensity of the reflexes corresponding to the lower part increases, and for this reason it has been said that the effectiveness of the upper centers modifies the effectiveness of the lower centers, and that the spinal cord works under the influence of external factors, but it does not create movement by itself. Damage to the spinal cord leads to sensitivity and voluntary movements, and results in major disruption of organ functions. This has led many to say that the spinal cord is necessary for the survival of life, and that life does not last without it. However, the experiments of Goltz and Evald proved the falsity of this opinion. These two scientists achieved the deletion of a large portion of the spinal cord in their experiments on dogs, but this did not endanger their lives. This is because damage to the spinal cord gives the sympathetic system a new status, according to the law of substitution, and it becomes

This sympathetic group manages the functions that he thought could only be carried out by the spinal cord.

2 - Functions of the bulb and cerebellum (Fonctions du bulbe et du cervelet) - The bulb (medulla oblongata) has a relationship: 1 - With the digestive system. Because the supplied nerves connected to the digestive system all end there 20 - with heart movements. Because it contains a center called the cardiac center, to which the nerves coming from the heart end. 3- Respiratory system. Because the nerves of this bulb are separate from the bulb, breathing movements cannot be regulated without them. In addition to that, the state of the blood has an effect on the respiratory center 40 - through speech and enunciation. Because it is the center of the nerves that move the vocal muscles. Yes, understanding the meanings of words does not occur except through the vibration of the cerebral cortex, except that the movements of the tongue, lips, and other things arise from the bulb of the organ.

As for the functions of the cerebellum, there is still some mystery in them, but Florence’s experiments indicated that the cerebellum is the organ that regulates voluntary movements. If a small layer of it is damaged, the animal begins to become confused in its voluntary movements, and this defect increases as the damaged section increases, so you see the animal. He seeks to regain the order of his sluggish, disturbed movements without achieving this goal. This indicates that the cerebellum is the center of the muscular system. The afflicted person suffers from a significant defect in his movements, changes the position of his forearms and legs, and is overcome by dizziness, as a result of which he feels that he is being sent to walk in a special direction. You see the voluntary act as being precise at its beginning, but the patient does not perform it well at the end. So the cerebellum is the center of balance, and it gives reflexive, instinctive, and voluntary actions control, precision, weight, and strength, and it has an important role in the mechanics of agitation and disturbance. However, we cannot describe it in this acronym

Brain functions: It is most likely that the brain is the organ of thinking, just as the stomach is the organ of digestion. The brain is the most valuable nerve center. However, removing it from a frog, for example, does not cause its death, but rather allows it to live for a period of time without being able to perform the natural actions that it used to perform. She cannot eat, nor can he hear

It croaks, and does not swim in water unless pushed into it, and does not move its limbs except after being stimulated by chemical acids. After losing the brain, the body becomes a mechanical machine with no trace of will, because all its movements are reflex actions. Therefore, it has been said that the brain participates in the movements of the body, and changes the conditions for their implementation, and that reflexive actions increase in intensity when the brain is lost, and that they are stronger in a sleeping person than in a awake person.

If we analyze the parts of the brain in depth, we find that they are so intertwined that it is difficult for the observer to identify them. Whoever remembers that influencing a cell calls for the dissemination of the energy contained within it, he will be startled to think about the relationships of brain cells to one another. Because each cell generates a special force, this force joins with others, and as a result a complex mixture occurs whose first elements are not easy to determine.