Physiology of muscular activity
Muscle activity is related to a basic property of muscle – ability to acronyms or airway. However, the muscles could be reduced if the muscle tisue have not had yet and physiological properties such as excitability and conductivity.
The property of contractility is manifested in the ability of the muscles to a single or total (tetanic) contractions. The body always happen tetanic, relatively long muscle contractions, because they receive not alone the momentum and flow of rhythmic impulses from the Central nervous system (CNS), and each of them calls the new contractile effect before the end of the reduction from the previous pulse. However, in experimental conditions it is posible to reproduce single reduction; the graphic image
of this reduction (of myogram) allows to allocate three phases: latent, or latent (thousandths of a second), the reduction phase and the relaxation phase (tenths or hundredths of a second).
Weak single reduction can take place only at a certain minimum strength irritation – Horny irritation, as well as diminishing only the most rapidly-excited fiber. The increase in the strength of excitation (up to a certain limit) leads to increased contractile effect because it reduced and les excitatory fibers.
Tetanic contraction is always stronger than a single, but each skeletal muscle has an optimal mode of irritation (from 100 to 200 pulses / sec) at which the reduction is strongest.
The muscles maintain a certain degree of tension, or tone, and when the reduction does not occur. Muscle tone is important to ensure a stable position of the body in space; only during sleep, both natural and drug, there is complete relaxation of the muscles, with the exception of the respiratory muscles, which continue to contract rhythmically (only for certain types of anesthesia are relaxing and breathing muscles). State of tonic muscle tension can be maintained by flow from the CNS single pulses that alternately stimulate different muscle fibers.