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Cells of the CNS : neurones (axon, dendrite, synapses). János Hanics M.D. Nervous system. Central nervous system (CNS), consisting of the brain and the spinal cord Peripheral nervous system (PNS), consisting of cranial and spinal nerves, ganglia, motor nerve endings, and receptors.
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Cells of the CNS: neurones (axon, dendrite, synapses) János Hanics M.D.
Nervous system Central nervous system (CNS), consisting of the brain and the spinal cord Peripheral nervous system (PNS), consisting of cranial and spinal nerves, ganglia, motor nerve endings, and receptors CNSdevelops from the neural tube PNSdevelops from the neural crest
Cells of the nervous tissue nerve cells - neurons supporting cells - glial cells
Neuron or nerve cell is a structural and functional unit of the nervous system . Nerve cells are specialized to receive stimuli and to conduct electrical impulses to other parts of the system arranged as an intercommunicating network, involved in sending impulses from one part of the system to another The synapses are specialized contacts between neurons.
The neuron Main parts of the neurons: Dendrites aremultiple elongated procecces specialized in receiving stimuli from the environment, from sensory epithelial cells and from other neurons. Perikaryon or cell body represents the trophic center for the whole nerve cell and it is also receptive to stimuli. Axon is a simple process specialized in generating and conducting impulses to other cells. The distal portion of the axon branches terminal arborization
Synapses Presynaptic component (bouton) – synaptic cleft (15-20nm) – postsynaptic component
Classification of synapses • According to their: • Localization • Structure • Function (electrical, chemical, excitatory and inhibitory) • Neurotransmitter substances (-ergic): • GABA • L-glutamate, L-aspartate • Ach • Noradrenaline • Dopamin • Serotonine • (and Cotransmitters)
Structure difference of synapses According to Gray: Type I: asymmetric synapse Type II: symmetric synaps
Receptors • Ionotropic (ion channels) • Metabotropic