The role of the striopallidar system, the limbic-reticular complex and the cerebellum in providing speech.

Seminar 1.

The strio-pallidar system began to provide a background of “preparedness” for the movement; against this background, fast, precise, strictly differentiated movements controlled by the cerebral cortex are carried out. To make a movement, it is necessary that some muscles contract and others relax. In other words, you need an accurate and consistent redistribution of muscle tone. Such a redistribution of muscle tone is carried out by the strio-pallidar system. It provides the most economical consumption of muscle energy in the process of performing a movement. Improving the movement in the process of learning to perform them (for example, working to the limit of the musician’s honed finger run, the mower’s hand wave, the exact movements of a car driver) leads to gradual economization and automation. This possibility is provided by the strio-pallidar system. Motor acts of the newborn are pallidary in nature: they are not coordinated, throwing and often redundant. With age, as the striatum matures, the child’s movements become more economical, stingy, automated. The strio-pallidar system has connections with the cerebral cortex, cortical motor system (pyramidal) and muscles, formations of the extrapyramidal system, with the spinal cord and thalamus. Other basal nuclei (fence and amygdala) are located outward from the lentiform nucleus. The amygdala nucleus is part of another functional system, the so-called limbic-reticular complex. The reticular formation is closely connected with the cerebral cortex (especially with the limbic system). Thanks to this, a functional connection is formed between the higher parts of the central nervous system and the brain stem. This system is called the limbic-reticular complex or the limbic-reticular axis. This complex structural and functional complex ensures the integration of the most important functions, in the implementation of which various parts of the brain participate. In turn, the reticular formation also receives impulses from the cerebellum, subcortical nuclei, and the limbic system, which provide emotionally adaptive behavioral responses and motivated behaviors. However, the degree of provision of adaptive unconditioned reflex reactions by a nonspecific system in humans and animals is different. If in animals the subcortical formations and the limbic system play a leading role in fulfilling the vital needs of the organism for its survival in the environment, then in humans, due to the dominance of the cortex, the activity of the deep structures of the brain (subcortical formations, limbic system, reticular formation) is more degree than in an animal, is subordinate to the cerebral cortex. The reticular formation plays an important role in the regulation of muscle tone, which is carried out along two types of reticulo-spinal tracts: the fast-conducting reticulo-spinal tract regulates fast movements, and the slow-conducting tract regulates slow tonic movements. The reticular formation of the medulla oblongata is involved in the occurrence of decerebrate rigidity. When the brainstem is transected above the medulla oblongata, the activity of neurons that have an inhibitory effect on the motor neurons of the spinal cord decreases, which leads to a sharp increase in the tone of the skeletal muscles.

Limbic system (litbicus – border) – a complex of brain structures related to emotions, sleep, wakefulness, attention, memory, autonomic regulation, motivations, internal urges; motivation includes the most complex instinctive and emotional reactions, such as food, defensive, etc. The term “limbic system” was introduced by Mac Lane in 1952. This system surrounds the brain stem like a shell. It is commonly referred to as the “olfactory brain” as it is directly related to the sense of smell and touch. Mood-altering drugs work specifically on the limbic system, which is why people who take them feel uplifted or depressed. The limbic system consists of the thalamus, hypothalamus, pituitary, hippocampus, pineal, amygdala, and reticular formation. The presence of functional connections between limbic structures and the reticular formation allows us to speak of the so-called limbic-reticular axis, which is one of the most important integrative systems of the body.

Seminar 3.

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