Neuronal communication o reception chemical signals

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Neuronal Communication oReception Chemical signals are received from neighboring neuronsWhere excitatory or inhibitory signals come in to the dendrites; all theneurotransmitters that get pushed out at the end are the ones making the signals oIntegration Incoming signals are assessed; happens in the cell body oTransmissionSignals are passed on to other receiving neurons Types of Neurons oSensory neurons These neurons detect information from the physical world and pass that information to the brain Somatosensory nerves provide information from the skin and muscles oInterneurons These neurons communicate within local or short-distance circuits oMotor neuronsThese neurons direct muscles to contract or relax, thereby producing movement Neuron Structure oDendritesBranchlike extensions of the neuron that detect information from other neurons; excitatory or inhibitory neurons come in oSomaThe site in the neuron where information from thousands of other neurons is collected and integrated; kind of like the brain of the neuron, main centeroAxonA long narrow outgrowth of a neuron by which information is transmitted to other neurons; electrical transmission happens oTerminal buttons
At the ends of the axons, small nodules that release chemical signals from the neuron into the synapse; neurotransmitters are releasedoSynapse (synaptic gap)The gap between the axon of a “sending” neuron and the dendrites of a “receiving” neuron and the side at which chemical communication occurs between neurons; space between the terminal buttons and the next neuron oMyelin SheathA fatty material, made up of glial cells, that insulates some axons to allow for faster movement of electrical impulses along the axon Sort of like wire insulation oNodes of Ranvier Small gaps of exposed axon, between the segments of myelin sheath, where action potentials take place**Know how to draw one Neural Communication oAction potential = neural firing The electrical signal that passes along the axon and subsequently causes the release of chemicals from the terminal buttons oResting membrane potential = electrical charge when neuron is not firing (-70mV) Polarized – more negative inside the cell Hyperpolarized – more negative outside the cell Neuronal Communication oIncoming signals: Excitatory (depolarizing) makes the cell less negative on the inside making the neuron fire. Inhibitory (hyperpolarizing) makes the cell less negative on the outside stopping the neuron from firing; want to keep the cell doing nothingoNeurons fire in an “all or none” principle (no such thing as a half firing neuron, it either fires or it doesn’t) oThink of incoming signals as polar bears: If you want to excite the polar bears to leave (depolarize) the area you should turn up the heat – make the climate warmer (+) If you want to inhibit the polar bears from leaving, hyperpolar-bear-

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