Ch 12 AP 3 PDF - Neural Tissue & Action Potential

Bloom’s Category: 1. Remembering 3. Which glial cells function as metabolic intermediaries between capillaries and neurons? a. Schwann cells b. Oligodendrocites c. Astrocytes d. Microglial cells Answer: c Textbook Reference: The Cellular Organization of Neural Tissue Bloom’s Category: 1. Rememberin...

Bloom’s Category: 1. Remembering 3. Which glial cells function as metabolic intermediaries between capillaries and neurons? a. Schwann cells b. Oligodendrocites c. Astrocytes d. Microglial cells Answer: c Textbook Reference: The Cellular Organization of Neural Tissue Bloom’s Category: 1. Remembering 4. Which term best describes the movement of ions across a membrane? a. Current b. Voltage c. Resistance d. Capacitance Answer: a Textbook Reference: The Ionic Basis of Membrane Potentials Bloom’s Category: 1. Remembering 5. A decrease in the absolute value of the membrane potential toward zero is called a. depolarization. b. an action potential. c. hyperpolarization. d. a membrane potential. Answer: a Textbook Reference: The Ionic Basis of Membrane Potentials Bloom’s Category: 1. Remembering 6. Which of the following actively contributes to the cell’s membrane potential? a. Permeability to K+ b. Permeability to Na+ c. The overall resistance of the membrane d. Electrogenic ion pumps Answer: d Textbook Reference: The Ionic Basis of Membrane Potentials Bloom’s Category: 5. Evaluating 7. The time constant (τ) depends on the _______ of the membrane. a. resistance b. capacitance c. resistance and voltage d. resistance and capacitance Answer: d Textbook Reference: The Ionic Basis of Membrane Potentials © 2016 Sinauer Associates, Inc. Bloom’s Category: 2. Understanding 8. If a current pulse is generated on the membrane and creates a passive potential, which statement will be true? a. The change in the membrane potential will increase as the distance from the current pulse increases. b. The change in the membrane potential will decrease as the distance from the current pulse increases. c. The change in the membrane potential will remain constant throughout the length of the membrane. d. The change in the membrane potential will fluctuate depending on the strength of the initial current pulse. Answer: b Textbook Reference: The Ionic Basis of Membrane Potentials Bloom’s Category: 3. Applying 9. The plasma membrane of a resting neuron is most permeable to which ion? a. Na+ b. K+ c. Cl– d. Ca2+ Answer: b Textbook Reference: The Ionic Basis of Membrane Potentials Bloom’s Category: 2. Understanding 10. If ouabain was used to block Na+–K+-ATPase pumps, a. Na+ would go to equilibrium across the cell membrane. b. the membrane potential would become more negative. c. the concentration of K+ would be equal on both sides of the membrane. d. the cell would maintain steady state with a different membrane potential. Answer: a Textbook Reference: The Ionic Basis of Membrane Potentials Bloom’s Category: 3. Applying 11. In a typical neuron, which ion is in passive equilibrium across the cell membrane? a. Na+ b. K+ c. Cl– d. Both Na+ and K+ Answer: c Textbook Reference: The Ionic Basis of Membrane Potentials Bloom’s Category: 2. Understanding 12. A stimulating depolarizing current that depolarizes the axon hillock just slightly negative to the threshold will a. not change the overall membrane potential at all. © 2016 Sinauer Associates, Inc. b. produce an action potential. c. produce a very small action potential. d. produce a temporary graded potential. Answer: d Textbook Reference: The Action Potential Bloom’s Category: 2. Understanding 13. _______ channels govern the generation of an action potential. a. Ligand-gated Na+ b. Ligand-gated K+ c. Voltage-gated Na+ d. Voltage-gated K+ Answer: c Textbook Reference: The Action Potential Bloom’s Category: 1. Remembering 14. Considering the cycle of an action potential, when is the permeability to K+ at its greatest? a. During the resting membrane potential b. During the rising phase of the action potential c. At the peak of the action potential d. During the falling phase of the action potential Answer: d Textbook Reference: The Action Potential Bloom’s Category: 2. Understanding 15. Which statement regarding the action potential is false? a. In an extremely long axon, the action potential eventually will degrade. b. During the “falling” phase, K+ permeability increases. c. During the “rising” phase, Na+ moves into the neuron. d. In the recovery phase, Na+ channels are closed. Answer: a Textbook Reference: The Action Potential Bloom’s Category: 5. Evaluating 16. What allows the action potential to return to a repolarized state? a. Voltage-gated Na+ channels become inactivated. b. Voltage-gated K+ channels become inactivated. c. Na+ reaches equilibrium across the neural membrane and stops leaking in. d. Voltage-gated Na+ channels close. Answer: a Textbook Reference: The Action Potential Bloom’s Category: 2. Understanding 17. Which statement regarding cardiac pacemaker cells is false? a. They spontaneously generate action potentials. © 2016 Sinauer Associates, Inc. b. The frequency of action potential generation can be modified by neural input. c. The pacemaker cells are modified neural tissue. d. They are connected to myocardium via gap junctions. Answer: c Textbook Reference: The Action Potential Bloom’s Category: 5. Evaluating 18. _______ are responsible for extending the time of the cardiac action potential relative to a neural action potential. a. Slow Ca2+ channels b. Slow Na+ channels c. Slow K+ channels d. Voltage-gated Na+ channels Answer: a Textbook Reference: The Action Potential Bloom’s Category: 2. Understanding 19. Which character of neurons affects conduction velocity the least? a. Axon diameter b. Myelination c. Axon length d. Temperature Answer: c Textbook Reference: The Propagation of Action Potentials Bloom’s Category: 5. Evaluating 20. In myelinated axons, action potentials occur a. all along the axon. b. only at the internodes. c. only at the initial segment of the axon. d. only at the nodes of Ranvier. Answer: d Textbook Reference: The Propagation of Action Potentials Bloom’s Category: 2. Understanding © 2016 Sinauer Associates, Inc.