CHAPTER 2 CELLULAR PHYSIOLOGY MCO (Please select the single best answer) A1型题 1.The action potential of a neuron A.is initiated by efflux of Na+ B.is terminated by efflux of K+ C.declines in amplitude as it moves along the axon D.results in a transient reversal of the concentration gradient of Na+ across the cell membrane E.is not associated with any net movement of Na+or K+across the cell membrane [答案]B 2. Which of the following has the slowest conduction velocity? A.Aa fibers B.AB fibers C.AY fibers D.B fibers E.C fibers [答案]E 3.A man falls into a deep sleep with one arm under his head.This arm is paralyzed when he awakens,but it tingles,and pain sensation in it is still intact. The reason for the loss of motor function without loss of pain is that in the nerves to his arm
CHAPTER 2 CELLULAR PHYSIOLOGY MCO (Please select the single best answer) A1 型题 1. The action potential of a neuron A. is initiated by efflux of Na+ B. is terminated by efflux of K+ C. declines in amplitude as it moves along the axon D. results in a transient reversal of the concentration gradient of Na+ across the cell membrane E. is not associated with any net movement of Na+ or K+ across the cell membrane [答案] B 2. Which of the following has the slowest conduction velocity? A. Aα fibers B. Aβ fibers C. Aγ fibers D. B fibers E. C fibers [答案] E 3. A man falls into a deep sleep with one arm under his head. This arm is paralyzed when he awakens, but it tingles, and pain sensation in it is still intact. The reason for the loss of motor function without loss of pain is that in the nerves to his arm
A.A fibers are more susceptible to hypoxia than B fibers B.A fibers are more sensitive to pressure than C fibers C.C fibers are more sensitive to pressure than A fibers D.sensory nerves are nearer the bone than motor nerves and hence are less affected by cooling E.sensory nerves are nearer the bone than motor nerves and hence are less affected by pressure [答案]B 4.Which part of a neuron has the highest concentration of Na+channels per square millimeter of cell membrane? A.Dendrites B.Cell body near dendrites C.Initial segment D.Axonal membrane under myelin E.None of the above [答案]C 5.Which of the following statements about nerve growth factor is not true? A.It is made up of three polypeptide subunits B.It is found in high concentration in the submandibular salivary glands of female mice C.It is necessary for the growth and development of the sympathetic nervous system D.It is picked up by nerves from the organs they innervate E.It is present in the brain [答案]B
A. A fibers are more susceptible to hypoxia than B fibers B. A fibers are more sensitive to pressure than C fibers C. C fibers are more sensitive to pressure than A fibers D. sensory nerves are nearer the bone than motor nerves and hence are less affected by cooling E. sensory nerves are nearer the bone than motor nerves and hence are less affected by pressure [答案] B 4. Which part of a neuron has the highest concentration of Na+ channels per square millimeter of cell membrane? A. Dendrites B. Cell body near dendrites C. Initial segment D. Axonal membrane under myelin E. None of the above [答案] C 5. Which of the following statements about nerve growth factor is not true? A. It is made up of three polypeptide subunits B. It is found in high concentration in the submandibular salivary glands of female mice C. It is necessary for the growth and development of the sympathetic nervous system D. It is picked up by nerves from the organs they innervate E. It is present in the brain [答案] B
6.The action potential of skeletal muscle A.has a prolonged plateau phase B.spreads inward to all parts of the muscle via the T tubules C.causes the immediate uptake of Ca2+into the lateral sacs of the sarcoplasmic reticulum D.is longer than the action potential of cardiac muscle E.is not essential for contraction [答案]B 7.The functions of tropomyosin in skeletal muscle include A.sliding on actin to produce shortening B.releasing Ca2+after initiation of contraction C.binding to myosin during contraction D.acting as a "relaxing protein"at rest by covering up the site where myosin binds to actin E.generating ATP,which it passes to the contractile mechanism [答案]D 8.The cross-bridges of the sarcomere in skeletal muscle are made up of A.actin B.myosin C. troponin D.tropomyosin E.myelin [答案]B 9.The contractile response in skeletal muscle
6. The action potential of skeletal muscle A. has a prolonged plateau phase B. spreads inward to all parts of the muscle via the T tubules C. causes the immediate uptake of Ca2+ into the lateral sacs of the sarcoplasmic reticulum D. is longer than the action potential of cardiac muscle E. is not essential for contraction [答案] B 7. The functions of tropomyosin in skeletal muscle include A. sliding on actin to produce shortening B. releasing Ca2+ after initiation of contraction C. binding to myosin during contraction D. acting as a "relaxing protein" at rest by covering up the site where myosin binds to actin E. generating ATP, which it passes to the contractile mechanism [答案] D 8. The cross-bridges of the sarcomere in skeletal muscle are made up of A. actin B. myosin C. troponin D. tropomyosin E. myelin [答案] B 9. The contractile response in skeletal muscle
A.starts after the action potential is over B.does not last as long as the action potential C.produces more tension when the muscle contracts isometrically than when the muscle contacts isotonically D.produces more work when the muscle contracts isometrically than when the muscle contacts isotonically E.decreases in magnitude with repeated stimulation [答案]C 10.Gap junctions A.are absent in cardiac muscle B.are present but of little functional importance in cardiac muscle C.are present and provide the pathway for rapid spread of excitation from one cardiac muscle fiber to another D.are absent in smooth muscle E.connect the sarcotubular system to individual skeletal muscle cells [答案]C 11. Which of the following is not synthesized in postganglionic sympathetic neurons? A.L-Dopa B.Dopamine C.Norepinephrine D.Histamine E.Acetylcholine [答案]D
A. starts after the action potential is over B. does not last as long as the action potential C. produces more tension when the muscle contracts isometrically than when the muscle contacts isotonically D. produces more work when the muscle contracts isometrically than when the muscle contacts isotonically E. decreases in magnitude with repeated stimulation [答案] C 10. Gap junctions A. are absent in cardiac muscle B. are present but of little functional importance in cardiac muscle C. are present and provide the pathway for rapid spread of excitation from one cardiac muscle fiber to another D. are absent in smooth muscle E. connect the sarcotubular system to individual skeletal muscle cells [答案] C 11. Which of the following is not synthesized in postganglionic sympathetic neurons? A. L-Dopa B. Dopamine C. Norepinephrine D. Histamine E. Acetylcholine [答案] D
12.Fast inhibitory postsynaptic potentials (IPSPs) A.are a consequence of presynaptic inhibition B.interact with other fast and slow potentials to move the membrane potential of the postsynaptic neuron toward or away from the firing level C.can be produced by an increase in Na+conductance D.can be produced by an increase in Ca2+conductance E.occur in skeletal muscle [答案]B 13.Initiation of an action potential in skeletal muscle by stimulating its motor nerve A.requires spatial facilitation B.requires temporal facilitation C.is inhibited by a high concentration of Ca2+at the neuromuscular junction D.requires the release of norepinephrine E.requires the release of acetylcholine [答案]E 14. Which of the following is a ligand-gated ion channel? A.VIP receptor B.Norepinephrine receptor C.GABAA receptor D.GABAB receptor E.Metabotropic glutamine receptor [答案]C
12. Fast inhibitory postsynaptic potentials (IPSPs) A. are a consequence of presynaptic inhibition B. interact with other fast and slow potentials to move the membrane potential of the postsynaptic neuron toward or away from the firing level C. can be produced by an increase in Na+ conductance D. can be produced by an increase in Ca2+ conductance E. occur in skeletal muscle [答案] B 13. Initiation of an action potential in skeletal muscle by stimulating its motor nerve A. requires spatial facilitation B. requires temporal facilitation C. is inhibited by a high concentration of Ca2+ at the neuromuscular junction D. requires the release of norepinephrine E. requires the release of acetylcholine [答案] E 14. Which of the following is a ligand-gated ion channel? A. VIP receptor B. Norepinephrine receptor C. GABAA receptor D. GABAB receptor E. Metabotropic glutamine receptor [答案] C
15. Which of the following is most likely not to be involved in production of LTP? A.NO B.Ca2+ C.NMDA receptors D.Membrane hyperpolarization E.Membrane depolarization [答案]D 16. Which of the following synaptic transmitters is not a peptide,polypeptide, or protein? A.Substance P B.Met-enkephalin C.B-Endorphin D.Serotonin E.Dynorphin [答案]D 17.Activation of which of the following receptors would be expected to decrease anxiety? A.Nicotinic cholinergic receptors B.Glutamate receptors C.GABAA receptors D.Glucocorticoid receptors E.a 1-Adrenergic receptors [答案]C
15. Which of the following is most likely not to be involved in production of LTP? A. NO B. Ca2+ C. NMDA receptors D. Membrane hyperpolarization E. Membrane depolarization [答案] D 16. Which of the following synaptic transmitters is not a peptide, polypeptide, or protein? A. Substance P B. Met-enkephalin C. β-Endorphin D. Serotonin E. Dynorphin [答案] D 17. Activation of which of the following receptors would be expected to decrease anxiety? A. Nicotinic cholinergic receptors B. Glutamate receptors C. GABAA receptors D. Glucocorticoid receptors E. α1-Adrenergic receptors [答案] C
18. Which of the following receptors is coupled to a heterotrimeric G protein? A.Glycine receptor B.GABAB receptor C.Nicotinic acetylcholine receptor at myoneural junction D.5-HT3 receptor E.ANP receptor [答案]B 19.Which of the following would not be expected to enhance noradrenergic transmission? A.A drug that increases the entry of arginine into neurons B.A drug that enhances tyrosine hydroxylase activity C.A drug that enhances dopamine B-hydroxylase activity D.A drug that inhibits monoamine oxidase E.A drug that inhibits norepinephrine reuptake [答案]A
18. Which of the following receptors is coupled to a heterotrimeric G protein? A. Glycine receptor B. GABAB receptor C. Nicotinic acetylcholine receptor at myoneural junction D. 5-HT3 receptor E. ANP receptor [答案] B 19. Which of the following would not be expected to enhance noradrenergic transmission? A. A drug that increases the entry of arginine into neurons B. A drug that enhances tyrosine hydroxylase activity C. A drug that enhances dopamine β-hydroxylase activity D. A drug that inhibits monoamine oxidase E. A drug that inhibits norepinephrine reuptake [答案] A