Chapter 8 Study Guide
1) 2) 3) 4) 5) 6) 7) 8) 9) 10) 11) 12) 13) 14) 15) 16) 17) 18) 19)
A threshold stimulus makes the membrane permeable to ions that rapidly diffuse into the neuron. A depolarized membrane is repolarized when ions diffuse out of the neuron. The membrane then reestablishes the resting state distribution of ions. When an impulse reaches the axon, nerve impulse conduction occurs.
In neuron-to-neuron synaptic transmission, a nerve impulse reaching a terminal bouton causes the formation of a synaptic cleft. The neurotransmitters are then removed from the synaptic cleft through reabsorption, diffusion, or decomposition by enzymes. If a drug prevents an excitatory neurotransmitter from binding to receptors of the postsynaptic neuron, synaptic transmission will not occur. Such a drug might be useful in a clinical situation.