Module 9 Samenvatting

agonist {Ans: a molecule that increases a neurotransmitter's action.}glial cells (glia) {Ans: cells in the nervous system that support, nourish, and protect neurons; they also play a role in learning, thinking, and memory.}all-or-none response {Ans: a neuron's reaction of either firing (with a full strength response) or not firing.}neuron {Ans: a nerve cell; the basic building block of the nervous system.}axon {Ans: the neuron extension that passes messages through its branches to other neurons or to muscles or glands.}refractory period {Ans: in neural processing, a brief resting pause that occurs after a neuron has fired; subsequent action potentials cannot occur until the axon returns to its resting state.}myelin [MY-uh-lin] sheath {Ans: a fatty tissue layer segmentally encasing the axons of some neurons; enables vastly greater transmission speed as neural impulses hop from one node to the next.}endorphins [en-DOR-fins] {Ans: "morphine within"—natural, opiate-like neurotransmitters linked to pain control and to pleasure.}reuptake {Ans: a neurotransmitter's reabsorption by the sending neuron.}action potential {Ans: a neural impulse; a brief electrical charge that travels down an axon.}cell body {Ans: the part of a neuron that contains the nucleus; the cell's life-support center.}neurotransmitters {Ans: