●They transmit info throughout the body. Very basic building block of the nervous system. ●Types of neurons: ○Sensoryneurons (cactus → brain)- send info from the physical world to the brain. Involves the five senses. EX. “This cactus is sharp” ○Interneurons (brain → spinal cord)- communicate between sensory and motor neurons (communicate between the other two; sensory and motor). “Hey apparently that cactus is sharp what should we do about it?” ○Motorneurons (CNS → muscles)- in charge of movements. “Look how big my muscles are” *Ford flexes* Tell muscles to contract or relax. “How about I pull my hand away from this cactus” ●Structure of a Neuron (info in dendrites → cell body → axon → axon terminal) ○Dendrites- branch like extensions that detect chemical signals from other neurons and carry them to the cell body. Help bring info from outside the cell to inside the cell. ○Cell body (Soma)- collects and integrates info received through the dendrites ○Axon- carries info from the cell body to the terminal buttons. ○Terminal buttons- release info from the neuron to the dendrites of other neurons. Then the process will start all over in the next neuron. ○EX. Airport analogy ■Dendrites are where you arrive at the airport. ■Cell body is the terminal where u find your flight. (organized and processed info) ■Axon (info travels down axon) would be your flight from memphis to somewhere.
■Terminal buttons is like the airport where you land a.k.a. Chicago Neural communication voors loves dick ●Synapse- gap between one neuron’s axon and another neuron’s dendrite. The space between two neurons.( EX. You continue your travels but your flight out of chicago leaves from the Midway) ●Neurotransmitters- chemical substances that travel across the synapse to transmit signals from one neuron to another. (taxi’s that go between the airports) ○*Get familiar with your neurotransmitters* ○Acetylcholine - motor control over muscles ○Epinephrine - fight or flight ○Dopamine - reward and motivation ○Norepinephrine - Arousal and attention ○Serotonin - emotions ○GABA - Inhibition of action potentials ○Glutamate - Excitation of action potentials ○Endorphins - pain reduction ●Action potential: neural firing- electrical signal that passes along the axon. ○Channels open: sodium rushes in, potassium rushes out (this changes the mV (positive and negative charge) ○Depolarization - becoming more positive inside the neuron (becoming more of the same on the inside and outside) ○Repolarization - becoming more negative (more opposite on the inside than the outside) luke cannon is gay ○The Maximum/Climax is Action potential (at the peak the channels close) ○1. Signal from the dendritesreaches minimum threshold ○2. Sodium & Potassium channels open (sodium in, potassium out)
○3. Neuron’s charge goes from negative to positive ○4. Signal goes down the axon ○5. Sodium & Potassium channels close ○6. Neuron returns to resting state ●Resting membrane potential: electrical charge of a neuron At Rest= -70 millivolts inside the cell (more negatively charged on the inside of the cell than on the outside = polarized).
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