AP Biology Nervous System Flashcards

9830380398	neuron	main cell of the nervous system	0
9830380399	glial cells	cells that support neurons (ex: Schwann cells)	1
9830380400	cell body	contains nucleus of the neuron	2
9830380401	dendrite	receive stimuli; highly branched extensions	3
9830380402	axon	conduct and propagate impulses	4
9830380405	sensory neuron	pick up stimuli from the environment and send to the brain	5
9830380406	motor neuron	sends impulses to muscles to create movement	6
9830380407	interneuron	neurons in the CNS that communicate internally and connect sensory to motor neurons; are responsible for reflexes	7
9830380408	resting potential	membrane potential of a neuron that is not firing, -70 mV	8
9830380409	sodium-potassium pump	protein that uses active transport to move 3 Na out of the membrane and 2 K in, which resets the neuron to resting potential	9
9830380410	action potential	rapid change in the voltage between the membrane of a neuron in response to a stimulus	10
9830380411	threshold	the voltage needed to open the voltage gated Na channels and start the unstoppable flow of Na into the cell, -55 mV	11
9830380412	depolarization	the massive influx of Na causes the cell's voltage to become less negative, all the way up to 35 mV	12
9830380413	repolarization	Na channels close and K channels open, which allows K out of cell so the cell is more negative	13
9830380414	hyperpolarization	because K channels are slow to close, the voltage reaches -80 mV, and causes the Na/K pump to reset the neuron	14
9830380415	refractory period	period where the neuron resets using the Na/K pump before a neuron can be fired again	15
9830380416	synapse	transmission of information is from one neuron to the next	16
9830380417	neurotransmitter	molecule that neurons use in synaptic transmission	17
9830380418	synaptic vesicle	hold the neurotransmitters in the presynaptic neuron	18
9830380421	myelin sheath	insulates the axon and speeds transmission of the impulse	19
9830380427	ion-gated channels	proteins responsible for allowing sodium or potassium to diffuse into or out of the axon	20
9830380428	sodium	ion responsible for depolarization	21
9830380429	potassium	ion responsible for repolarization	22
9830380430	calcium	ion that signals vesicles to release neurotransmitters	23
9830465087	K+ channels close and Na+ channels reset		24