General anesthetics, anesthetic funds in therapeutic doses cause reversible inhibition of spinal reflexes, loss of consciousness, all kinds of sensitivity, decreased skeletal muscle tone with preservation of the respiratory and vasomotor centers. At the heart of the action of drugs on the processes that lead to the disruption of synaptic transmission interneural that results to the development of the state of anesthesia. High sensitivity of the synapses have a regular formation and cerebral cortex, synapses are less sensitive spinal cord and least sensitive synapses of the medulla oblongata, where the respiratory and vasomotor centers. The relatively low sensitivity to anesthesia means the last centers of the medulla can maintain their concentration in the blood levels preserving respiratory function and cardiovascular system. Lightweight are ideal for the absorption of gases, which creates favorable conditions for general anesthesia.