Psych 1010 Brain Terms Flashcards

1059564726	neuron	specialized cell in the nervous system that accumulates and transmits information
1059564727	dendrites	the branched part of a neuron that receives impulses and conducts them toward the cell body
1059564728	cell body	the portion of the neuron containing the metabolic machinery that keeps the cell alive and functional (nucleus)
1059564729	axon	the part of a neuron that transmits impulses to glands, muscles, or other neurons
1059564730	efferent neurons	nerves that carry messages outward from the central nervous system
1059564731	afferent neurons	nerves that carry messages inward toward the central nervous system
1059564732	interneurons	neurons that are neither efferent nor afferent, but instead carry information from one neuron to another
1069727172	glia	a type of cell in the nervous system long believed to provide a "support" function for neurons; recent research indicates that glia provide many other functions as well
1069727173	myelin	a fatty substance that makes up some types of glial cells; these cells wrap around the axon of some neurons, providing an insulating "myelin sheath" around these neurons [myelinated axons = "white matter"]
1069727174	action potential	a brief change in the electrical charge of a neuronal membrane; the physical basis of the signal that travels the length of the neuron (fundamental information carrier of the nervous system)
1069727175	resting potential	the voltage difference between the inside and the outside of a neuronal membrane when the neuron is not firing (~-70 millivolts)
1069727176	excitation threshold	the voltage difference between a neuron's interior and exterior that, if exceeded, causes the neuron to fire (~-55 millivolts). In this millisecond-long occurrence, the voltage difference collapses and reverses, so that the difference is closer to +40
1069727177	refractory period	the time after an action potential during which a neuron's cell membrane is unprepared for the next action potential (only a few milliseconds)
1069727178	depolarize	in the nervous system, to lose the charge that normally exists across neuronal membrane. happens in a domino-like sequence along the axon
1069727179	propagation	the spread of the action potential down an axon, caused by successive changes (domino-like) in electrical charge along the length of the axon's membrane
1069727180	all-or-none law	the law that all action potentials have the same strength and speed regardless f the triggering stimulus
1070901457	synapse	the small gap between two adjacent neurons, consisting of the presynaptic and postsynaptic neurons' membranes and the space between them
1070901458	neurotransmitters	chemicals released by one neuron (usually the presynaptic neuron), which trigger a response in another neuron (usually the postsynaptic neuron); the chief means of communication among neurons
1070901459	synaptic reuptake	the presynaptic neuron's process of reabsorbing its own neurotransmitters after signaling so that they can be released again the next time the neuron fires (prevents them from still exerting effects even after neuron fires)