Synapse – it morphofunctional about nal CNS formation which provides signal transmission with no minutes Rhone to another neuron or effector cell (muscle secret p reversed). Synapse includes three components: presynaptic of membrane and on, and the postsynaptic membrane synaptic cleft, t. e. It comprises e e cops and the first and second contacting neurons.
By localization, synapses are divided into central and peripheral. Central are subdivided into axo-axonal, axo-dendric, axo-somatic, dendro-dendric and t. d .; in development in ontogenesis, stable and dynamic synapses are distinguished, in the final effect, inhibitory and excitatory. By signaling mechanism synapses b s vayut electrical, chemical and mixed.
The electric synapse is a slit-like formation with ion bridges-channels between two contacting cells. In the presence of PD almost unimpeded current jumps through slits e prominent contact and PD induces lasing in another cell, such arr and Zoom is a rapid transfer of excitation. But electrical synapses mostly have two-way conductivity. In addition to their claim of power can not be forced effector cells to inhibit their activity. On the other hand, signal transmission occurs almost without synaptic delay and almost without leakage of currents through the extracellular environment. Electrical e Synapses are widespread in the nervous system of invertebrates and lower vertebrates. In the brain stem of mammals, they are present in the nuclei of the trigeminal nerve and some other nuclei of the trunk.
Chemical synapses transfer the nerve signal with the power of chemical substances – mediators, which are contained in the synapt and visual symbols. Chemical synapses are classified by the nature of the m th diatora they use: cholinergic (acetylcholine), adr e nergicheskie (adrenaline), dopaminergic (dopamine), and others.