From biology lessons, we remember that the cerebellum is responsible for the coordination of movements. But besides him, in the human brain there are two systems responsible for controlling movements. They are interconnected and work together. The first system is pyramidal. She controls arbitrary movements. And the second is extrapyramidal. It contains red nuclei.
Physiology
Red nuclei appeared as a result of a large accumulation of neurons along the entire length of the midbrain. They have a red color, since there are a large number of capillaries and iron-containing substances in neurons. Nuclei consist of two parts:
- Small cell. In this part lies the beginning of the red-nuclear-olivar tract. This part began to develop in the brain due to the fact that a person began active movement on two limbs. With millennia, it has developed more and more.
- Large cell. In this part lies the beginning of the rubrospinal tract. This part has always been with an ancient person. In fact, it is the motor center.
Due to the connections of the red nuclei and cerebellum, the extrapyramidal system affects all skeletal muscles. In addition, they have projections to the nuclei of the spinal cord.
Functions of Red Cores
Their main function is to provide a connection and the transfer of information coming from the cerebellum and brain, more precisely its cortex, to all underlying structures. In a sense, this can be called the regulation of unconscious automatic movements. In addition to the main function, red kernels perform other, no less important tasks:
- Providing an open path between the extrapyramidal system and the spinal cord.
- Support the active work of all skeletal muscles of the body.
- Coordination of movements with the cerebellum.
- Control of automatic movements, for example, a change in body position in a dream.
The role of red cores
Their role is to ensure the transition of efferent signals from the nucleus itself to other neurons in a special way. After successfully passing the signal, the motor muscles of the limbs receive all the necessary information. Through a special path, red nuclei help simplify the beginning of the process of active work of motor neurons, and neurons also help regulate the motor abilities of the spinal cord.
But what will happen if damage to this path occurs? After disturbances in connections with the red core of the midbrain, the following syndromes begin to develop, which are fraught with death in most cases.
Pathology in violation
It all started with the fact that science has received a description of strong muscle tension in animals. Tension was created by breaking off the bonds of the red core. This precipice is called decerebral rigidity. Based on this observation, they concluded that the loss of connection between the red and vestibular nuclei causes severe tension in the skeletal muscles, muscles of the limbs, as well as the muscles of the neck and back.
The above muscles are distinguished by their ability to counteract gravity, therefore, it was concluded that such a development of events is associated with the vestibular system. As it turned out later, the vestibular nucleus of Deiters is able to start the work of extensor motor neurons. The activity of these neurons is significantly slowed down under the influence of the red nuclei and the Deuterium nucleus.
It turns out that the active work of muscles is the result of the joint work of the whole complex. In humans, decerebral rigidity occurs due to traumatic brain injuries. You can also encounter this phenomenon after a stroke. It should be understood that such a condition is a bad sign. You can find out about its availability by the following signs:
- arms are straight, divorced in different directions;
- hands are palms up;
- all fingers are compressed except for the large;
- legs are stretched and folded together;
- the feet are extended;
- toes are compressed;
- jaws firmly pressed against each other.
With injuries, serious infectious diseases, all kinds of internal lesions of organs, including the brain, also tumor processes and aggression of the immune system - all this leads to disruption of the brain. Thus, in the event of a breakdown in connections with the red nuclei, decerebral rigidity, as well as disruption of the eyeball and eyelid muscles, can occur, the latter being an easier reaction of the body to breaking the bonds.
Claude's syndrome
In 1912, when the famous transatlantic liner Titanic crashed and the first metro line was opened in Hamburg, Henri Claude first described the syndrome, which got its name in honor of the discoverer. The essence of Claude's syndrome is that when the lower part of the red nuclei is damaged, the fibers from the cerebellum to the thalamus, as well as the oculomotor nerve are damaged.
After a lesion, the patient’s muscles of the eyelid cease to work, due to which they drop or one eyelid drops on the side where the violation occurred. Also, pupil expansion is observed, divergent strabismus appears. Weakness of the body, tremor of the hands.
Claude's syndrome - due to damage to the lower part of the red nucleus, through which the root of the III nerve passes. In addition, dento-ruble bonds passing through the upper leg of the cerebellum. In violation of these most important connections in a person, intentional trembling, hemataxia, and muscle hypotension begin.
Benedict's Syndrome
The Austrian physician Moritz Benedict in 1889 described the condition of a person and his behavior in case of damage to the red nuclei. In his writings, he wrote that after such a violation, the connection between the structure of the oculomotor nerve and the cerebellum ceased.
The doctor’s observation was aimed at the fact that the pupil dilated on the injured side, and severe tremor began on the opposite side of the patient. Also, the patient began to make erratic, chaotic, wriggling movements of the limbs.
It is these observations that formed the basis of Benedict's syndrome. Benedict's syndrome occurs when the midbrain is damaged at the level of the red nucleus and cerebellar-rednuclear pathway. It combines paralysis of the oculomotor nerve and trembling of the face on the opposite side.