1 29 15 video epileptic man that had his connection corpus coliseum between hemispheres cut two brains that both can almost work independently Left hemisphere need to explain causes interprets thoughts feelings most important side Right hemisphere of brain is speaking brain recognize faces specialization of function between sides of hemispheres The Brain Behavior Chapter 2 Part 3 Nerve Cells neurons their Messages Neurons specialized cell of the nervous system that is used to detect information from outside world senses transmit information from part in body to another location in brain and affect muscles and glands so that we can respond appropriately look different than other cells A Cell circle nucleus mitochondria endoplasmic reticulum ribosomes lysosomes Golgi bodies vs A Neuron nucleus dendrites axon cell body myelin sheath axon ending Dendrites receive messages from neighboring neurons tree branches spreading looking things on the end new skill neurons adapt to new thing b c plasticity causes them to grow more dendrites Soma cell body attached is long tube like structure axon Axon length depending on how far it has to travel conducts nerve impulse from the cell body to distant location Myelin Sheath increases speed efficiency of nerve impulse on top of tube like structure layer of insulation helps conduct electricity down wire tube like plastic wire coating Terminal Buttons Round balls axon ending synaptic knobs when axon starts to split turn into arms with balls on the end that look like doorknobs then release chemicals that are stored at end of buttons when signal is received it squirts out its chemicals Neurotransmitters The Neural Impulse the electrical message within a neuron Electrochemical Electricity Communication from nerve cell to nerve cell dendrites soma cell body axon terminal buttons Electrical Impulses Chemical Messages How does it generate its own electricity Cerebral spinal fluid inside neuron cytoplasm ex lose electron positive charge gain electron negative charge Answer charged particles called Ions Sodium Na Potassium K Chloride Cl need for neurons to work properly Inside Outside of Neuron more positively neurons on the outside so more negatively charged on the inside ex Battery The Neural Impulse Resting Membrane Potential difference in charge voltage across the cell membrane around 70 millivolts inside more negatively than outside Sodium wants inside Axon but when neuron is resting the gates are closed sometimes they are open if any leaks in it is thrown out Threshold minimum amount of stimulation necessary to open channels trigger the neural impulse Stimulation sodium channels open gets inside rushing in Sodium is positive causes inside of cell to become more more since inside is then any positive ions potassium is repelled and leaves When this happens activates next sodium channel Na in K out over over over neural impulse just exchange of charged particles Action Potential brief wave of positive electrical charge that sweeps down the axon brief wave of positive charge of sodium coming in that happens all the way down the axon neurons firing neuron producing an action potential pumps embedded in membrane grab sodium molecules and pump them out reset back to square one This all happens instanteously Refractory Period siting useless ex mousetrap enough stimulation trigger a beginning it can snap again until I reset it make it do an action potential cannot do another one until you reset it after neuron fires there is a period of time when it cannot fire again All or None Law there is no half way either get an action potential or not if threshold is reached a full action potential occurs if threshold is not attained then no action potential will occur Electrochemical Transmission communication from nerve cell to nerve cell electrical impulses chemical messages once it resets terminal synaptic gap or synapse chemical messages squirted out transmitters that stimulate dendrites on other side Terminal buttons eject chemicals called neurotransmitters into the synaptic gap Synaptic Transmission Q what happens when the action potential reaches the terminal buttons at the end of the neuron A terminal buttons eject chemicals called neurotransmitters into the synaptic gap Synaptic Vesicles store neurotransmitters Can t be released has to be in vesicles to be able to be squired out ex mail must be in box package Neurotransmitters chemical messages They they re ejected into synapse Receptors receive neurotransmitters Synaptic Transmission pulling it all together dendrites cell body axon terminal buttons neurotransmitter release dendrites cell body axon terminal buttons etc
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