The role of the spinal cord in the regulation of motor activity. 

With uch as spinal cord pation carried primitive processes regulating skeletal muscle activity, allowing to perform phase-type motion of flexion and extension in the respective joints, as well as regulatory and ruyuschie muscle tone. The regulation of muscle tone is carried out with the participation of two types of reflexes of the spinal cord: myotatic and postural-tonic. Phase activity and represented flexor reflex mechanism and E, initiating locomotor movement (stepping movement). In about Nova reflex spinal reflex activity lie d in ghee presented afferent neurons (they lie in spinnomozg about out ganglia), intercalary neurons, as well as motor neurons. Among motoneurons, there are alpha motoneurons and gamma motoneurons. Al s F-motoneurons are designed to activate the most muscle, or extrafusal, fibers. Gamma motoneurons activated myshe h nye fibers that make up the muscle spindles (intrafusal in about Loknya) and thereby regulate muscle sensitivity Ver e spots stretchability.

Miotaticheskogo reflex (synonyms – reflexes tensile stretch reflex) – a group of reflexes (such as a knee-jerk, Achilles reflex), commonly referred to as tendon, because in the clinic for their identification struck by neurologic hammer on to have hozhiliyu corresponding muscle. This type of reflexes, played by C. Sherrington in the study of a large role , is considered as a mechanism for the automatic regulation of muscle activity in accordance with its length and speed of shortening or lengthening. The basis of the myotatic reflex is negative feedback from the muscle spindles to alpha-motoneurons. These reflexes play an important role in maintaining tone.

Flexion reflexes occur under the influence of the flow of impulses coming from the skin receptors – tactile, temperature, pain. These streams are called flexor reflex afferents. All and m pulses excite the alpha motor neurons flexor ipsi-lateral to about finiteness and simultaneously inhibit the alpha motor neurons of the extensors of the same limb. There is flexion in the corresponding joint and “care” from the damaging factor.

Reflex pacing movements . If you put a newborn baby on a hard surface of the table, supporting it, it may be noted pojavl e of his series of stepping movements. This is the manifestation of the reflex of the walking movements, which the child retains for about the first two months of life. This reflex, however, no classical Reflect p Noah arc and classical ways of its activation. It is believed that the reflex step and relative motion of the – this is one of the variants of the functioning of the neural structures in which the pre-laid “program” actions (CE n trawling pacing generator, generator pacing right and left legs).

Postural-tonic reflexes spinal directed to SUPPORTED and of the posture. With their help, the muscle tone is regulated. These reflexes fuss and mess from the proprioceptors of the neck muscles and regulate muscle tone and when s Menen position of the head and neck.

Pathological reflexes . When bunks in shenii supraspinal influences a person may receive a group of spinal reflexes, which have so camping is normally only in the first days and months of postnatal development. Rasto p mazhivanie these primitive refle to cos a clinical sign of disorders of the brain (there are certain techniques that allow th conductive detect these so-called n and ontological reflexes).

local_offerevent_note May 6, 2019

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