Name:______Psych 260- Quiz 3

(With the exception of the last question, each question is worth 1 pt. Write your answers for the last question directly on the quiz, and hand it in along with your scantron. Be sure to put your name on both the scantron and your quiz!)

1. The strength or intensity of a neuronal signal is determined by a. The size of the action potential b. The rate of firing of a neuron c. The type of receptor that is activated d. The type of neuron that is activated e. The particular neurotransmitter(s) that are released

2. In one cycle of neural communication, which is the correct order of events? a. Neurotransmitter release -> action potential -> threshold of excitation reached -> inhibitory or excitatory post-synaptic potential b. Threshold of excitation reached -> action potential -> neurotransmitter release -> inhibitory or excitatory post-synaptic potential c. Threshold of excitation reached -> neurotransmitter release -> action potential -> inhibitory or excitatory post-synaptic potential d. Inhibitory or excitatory post-synaptic potential -> neurotransmitter release -> threshold of excitation reached -> action potential e. Action potential -> threshold of excitation reached - > neurotransmitter release -> inhibitory or excitatory post-synaptic potential

3. In its resting state, a neuron is said to be a. Polarized b. Depolarized c. Hypopolarized d. Hyperpolarized e. Sleepy

4. The brief period of time immediately after the initiation of an action potential when it is impossible to initiate another one in the same neuron is called the a. Threshold of excitation b. Threshold of inhibition c. IPSP d. Relative refractory period e. Absolute refractory period

5. The portion of a neuron that carries a signal toward the cell body is the a. Soma b. Axon terminal c. Presynaptic membrane d. Dendrite e. Glial membrane

6. The membranes that most commonly form synapses are the _____and the _____. a. Axon terminals; dendrites b. Dendrites; soma c. Axon terminals; soma d. a and b e. a and c 7. The ______neuron is the most common nerve cell type in the central nervous system a. Apolar b. Multiglial c. Unipolar d. Bipolar e. Multipolar

8. Neurotransmitter molecules are secreted from the ______in response to the arrival of an action potential. a. Glial cell b. Dendrite c. Axon terminal d. Mitochondrion e. Soma

9. Movement of the axon membrane potential from -70 mV to -90 mV would be called a(n) a. Action potential b. Threshold potential c. Depolarization d. Hyperpolarization e. Excitatory local potential

10. The membrane voltage level at which an action potential is triggered is called the a. Refractory period b. Hyperpolarization event c. Threshold of excitation d. Rate level e. Equilibrium point

11. ______are positively charged particles. a. Transmitters b. Solvents c. Anions d. Cations e. None of the above

12. The process by which similarly charged particles repel each other and are thus distributed throughout a medium is called a. Diffusion b. Carrier-mediated transport c. Refraction d. Electrostatic pressure e. Diffraction

13. Neuronal signals are carried across the synapse by a. direct electrical connections between the two cells. b. the secretion of transmitter molecules into the synapse. c. the transfer of proteins from one cell to another. d. an inhibitory effect of a transmitter molecule on the presynaptic membrane. e. None of the above.

14. Match up the receptor type with its action. a. Metabotropic; direct opening of an ion channel b. Ionotropic; more time required to open an ion channel c. Metabotropic; G-protein activation leads to activation of a second messenger d. Metabotropic; rapid and short-lived effects on ion channels e. Ionotropic; opening of a channel through by a second messenger

15. Which of the following will “neutralize” the effect of an EPSP? a. Further opening of a sodium channel b. Allowing intracellular anions to leave the cell c. Closing a potassium channel d. Opening a chloride channel e. Both b and d are correct

16. Name three kinds of glial cells and briefly describe their function(s). (5 points)

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