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ELECTROCHEMICAL NEUROTRANSMISSION

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ELECTROCHEMICAL NEUROTRANSMISSION. There are 100 trillion neurons Each of them connect, interact with as many as 1,000 other neurons across a gap called the SYNAPSE So maybe there are 100 quadrillion synapses in the brain!! - PowerPoint PPT Presentation

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ELECTROCHEMICAL NEUROTRANSMISSION

ELECTROCHEMICAL NEUROTRANSMISSIONThere are 100 trillion neuronsEach of them connect, interact with as many as 1,000 other neurons across a gap called theSYNAPSESo maybe there are 100 quadrillion synapses in the brain!!A synaptic gap is about 20 A wide; 1A is .0000001 mmits very small

ANATOMY OF A NEURON

DENDRITECELL BODYNUCLEUSAXON HILLOCKAXONMYELIN SHEATHNODES OF RANVIERAXON BOUTON

DENDRITES ARE THE RECEIVING END OF THE NEURONAXONS ARE THE SENDING END OF THE NEURON

AXON HILLCOK ADDS UP (SUMMATES) INFORMATION COMING IN TO THE RECEIVING END OF THE NEURONTHE DENDRITESAS WELL AS THE CELL BODY THE MESSAGES (AT THE RECEIVING END) TELL THE NEURON TO PASS ITS CHARGE (INFORMATION) ALONG ITS AXON TO ITS SENDING END, OR NOTYES AND NO MESSAGES ARE SUMMATED AT THE AXON HILLOCK; SPATIALLY, TEMPORALLYIF/WHEN THE AXON DECIDES YES, IM GOING TO PASS MY MESSAGE ALONG, THE ELECTRO PART OF ELECTRO CHEMICAL NEUROTRANSMISSION BEGINSCOMMUNICATION AMONG NEURONS OCCURS VIA: ELECTRO (within the neuron)CHEMICAL (between neurons)NEUROTRANSMISSIONELECTRO PART

AXONS AT REST HAVE IONS UNEVENLY DISTRIBUTED ACROSS THEIR MEMBRANES;THAT IS, THERE ARE MORE NEGATIVELY CHARGED IONS INSIDE THE AXON THAN OUTSIDETHIS CREATES A TENSION ACROSS THE MEMBRANE

IN ADDITION, Na+ (sodium) and K+ (potassium) ARE ALSO UNEVENLY DISTRIBUTED ACROSS THE MEMBRANESODIUM IS MORE HIGHLY CONCENTRATED ON THE OUTSIDE OF THE AXON MEMBRANEPOTASSIUM IS MORE HIGHLY CONCENTRATEDL ON THE INSIDE OF THE AXON MEMBRANEWHEN THE AXON HILLOCK DECIDES, YES, I WANT TO PASS MY MESSAGE DOWN MY AXON TO COMMUNICATE WITH OTHER NEURONS AT THE END OF MY AXON, MAGIC HAPPENS

THE AXON MEMBRANES OPEN UP AND BECOME PERMEABLE TO THE UNEVEN DISTRIBUTION OF + AND IONS AND THEY SEEK EQUILIBRIUM DOWN THEIR ELECTROSTATIC GRADIENTIN ADDITION, K+ AND Na+ SEEK EQUILIBRIUM DOWN THEIR CONCENTRATION GRADIENT; CALLED THE SODIUM-POTASSIUM PUMPTHE EXCHANGE OF + AND IONS AND THE EXCHANGE OF K+ AND Na+ CAUSES MOVEMENT OF THE MESSAGE DOWN THE LENGTH OF THE AXONTHIS OCCURS MORE QUICKLY IN MYELINATED AXONS THAN NON-MYELINATEDWHEN THIS ACTIVITY REACHES THE END BOUTON,

THE CHEMICAL PART OF ELECTROCHEMICAL NEUROTRANSMISSION BEGINSNEUROTRANSMITTERS ARE:

Synthesized in cell body;

Stored in vesicles in end boutons;

Released into the synapse;

Travel across the synapse to the

Receptor on the post-synaptic neuron; and then the signal is

Terminatedeither through enzymatic degradation or reuptake.

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