From the lessons of biology, we remember that the cerebellum is responsible for the coordination of movements. But besides it, there are two systems in the human brain that are responsible for controlling movements. They are interconnected and work together. The first system is pyramidal. She controls voluntary 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 are red in color, since there are a large number of capillaries and iron-containing substances in neurons. The kernels 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. Over the millennia, it has evolved more and more.
- Large cell. In this part lies the beginning of the rubrospinal tract. This part has always been with ancient man. In fact, it is the moving center.
Due to the connections of the red nuclei and the cerebellum, the extrapyramidal system influencesto 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 communication and transition of information coming from the cerebellum and the brain, or rather 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 cores perform other equally important tasks:
- Providing an open pathway between the extrapyramidal system and the spinal cord.
- Support active work of all skeletal muscles of the body.
- Coordination of movements with the cerebellum.
- Control automatic movements, such as changing body position while sleeping.
Role of red cores
Their role is to ensure the transition of effer signals from the nucleus itself to other neurons along a special path. After the successful passage of the signal, the motor muscles of the limbs receive all the necessary information. Through a special tract, red nuclei help to facilitate the start of the process of active work of motor neurons, and neurons also contribute to the regulation of the motor abilities of the spinal cord.
But what happens if this path gets corrupted? After violations of connections with the red nucleus of the midbrain, the following syndromes begin to develop, which in most cases are fraught with death.
Pathologies in violation
Allbegan with the fact that science received a description of strong muscle tension in animals. The voltage was created by breaking the bonds of the red core. This break is called decerebrate rigidity. Based on this observation, they concluded that when the connection between the red and vestibular nuclei is lost, there is a strong 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 the gravity of the earth, so 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 motoneurons. The activity of these neurons is significantly slowed down under the influence of the red nuclei and the nucleus of Deiters.
It turns out that the active work of the muscles is the result of the joint work of the entire complex. In humans, decerebrate rigidity occurs as a result of traumatic brain injury. You can also experience this phenomenon after a stroke. It should be understood that this condition is a bad sign. You can find out about its availability by the following features:
- arms straight, spread apart;
- hands lie palms up;
- all fingers clenched except for the thumbs;
- legs outstretched and folded together;
- feet extended;
- toes clenched;
- jaws pressed tightly against each other.
In case of injuries, severe infectious diseases, all kinds of internal lesions of organs, including the brain,as well as tumor processes and aggression of the immune system - all this leads to disruption of the brain. Thus, in case of violation of connections with the red nuclei, decerebrate rigidity can occur, as well as disruption of the eyeball and eyelid muscles, the latter - an easier reaction of the body to breaking the connections.
Claude 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 affected, the fibers from the cerebellum to the thalamus, as well as the oculomotor nerve, are damaged.
After the lesion, the muscles of the eyelid stop working in the patient, because of which they drop or one eyelid droops on the side where the violation occurred. Pupil dilation is also observed, divergent strabismus appears. There is 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 third nerve root passes. In addition, dentorubral connections passing through the superior cerebellar peduncle. If these important connections are violated, a person begins intentional trembling, hemiataxia, and muscle hypotension.
Benedict Syndrome
Austrian doctor Moritz Benedict in 1889 described the condition of a person and his behavior in the defeat of red nuclei. In theirIn 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 directed to the fact that the pupil was expanding on the damaged side, and on the opposite side the patient began to have a strong tremor. Also, the patient began to make erratic, chaotic, wriggling movements of the limbs.
It was these observations that formed the basis of the Benedict syndrome. Benedict's syndrome occurs when the midbrain is damaged at the level of the red nucleus and the cerebellar-red nuclear pathway. It combines oculomotor nerve palsy and facial trembling on the opposite side.
