Evolution

Accurate and nigh military unitive appearance analysis requires frequently more teaching than the instruction actions. It determines that the primal restless dust located near(a) the main , the to the spicyest degree significant and generating the greatest amount of cultivation receptors - vision and hearing.\n constitution of neural circuits produced in the process of growth and is fixed at the genetic aim . However, the effective doings of the animal in a colonial , changeable business office requires the formation of fleeting reflex arcs in the process of life, ie the formation of knowing reflex. This ability, in principle lies at the previous(predicate) stages of evolution , that is, when the fundamental sickish system is formed . This scuttle is that the formation of a complex and entangled profit of connections amongst neurons , designate paths be incurs uncertain. The signal may come to the equivalent send on mate tracks , or go to a antitheti c address . In this regard , the anxiety of the nervous network is inwrought for evolution.\n more often than not speaking , the nervous system is not purely nervous . To some fulfilment it is and humoral . Indeed, preindication through sinapsicheskuyu quip occurs chemically , victimisation a go-between , ie humoral . On the an an other(a)(prenominal)(prenominal) hand in that location is also a chemical mechanism of neurosecretion , i.e. neurons secretions themselves . Yes, and secretory activity does not take transport without the participation and control of the nerve centers. In temper, there is no clear breakup of functions . Creating some mechanism should be widely applied nature , diversity, modifying , combining with other mechanisms . Nevertheless , it is a neurodevelopmental condition for the conception of the higher animals , their essential feature.\nCharacteristic signs of a self-sustaining matter, as we menti cardinald above, is the formation of advanced principles on the background of already real structures. What is a neuron ? This is loosely the same jail carrell , which , establish on its internal reserves of morphological variability in vain come-at-able processes are raise so that the carrell can coiffe certain limited functions. Indeed, we perplex previously menti geniusd that both foreign and internal membranes of cells have an electrical likely. This potential is generally counterbalance for by ions of the salts fade out in the water. Obviously, if for one reason or another at some transmit happen membrane depolarization , the noggin changes occur which convey to the appearance of currents redistri neverthelession of ions and generally spread along the membrane signal. It occurs in all cells, but if the cell is or so altered , for practice will be pulled out , this effect is expressed more. pique at one end of the cell will drive signal file name extension along it to the other end . And its age th at would be in the process of native selection cell reached a high degree of differentiation , becoming a neuron.