A 48-year-old man has hepatic cancer that is unresponsive to standard therapy. He enrolls in a clinical study of a novel chemotherapeutic agent that, as a side effect, blocks kinesin, a component of the cellular microtubular transport system. One week later, he develops skeletal muscle weakness An alteration in which of the following components of the neuromuscular junction is the most likely cause of the muscle weakness? (A) A decrease in the number of postsynaptic neurotransmitter receptors (B) A decrease in the number of presynaptic neurotransmitter vesicles (C) A decrease in the presynaptic neuron calcium permeability (D) Impaired a-motoneuron action potential conduction (E) Impaired skeletal muscle action potential conduction

A 48-year-old man has hepatic cancer that is unresponsive to standard therapy. He enrolls in a clinical study of a novel chemotherapeutic agent that, as a side effect, blocks kinesin, a component of the cellular microtubular transport system. One week later, he develops skeletal muscle weakness An alteration in which of the following components of the neuromuscular junction is the most likely cause of the muscle weakness? (A) A decrease in the number of postsynaptic neurotransmitter receptors (B) A decrease in the number of presynaptic neurotransmitter vesicles (C) A decrease in the presynaptic neuron calcium permeability (D) Impaired a-motoneuron action potential conduction (E) Impaired skeletal muscle action potential conduction

Human Anatomy & Physiology (11th Edition)

11th Edition

ISBN:9780134580999

Author:Elaine N. Marieb, Katja N. Hoehn

Publisher:Elaine N. Marieb, Katja N. Hoehn

Chapter1: The Human Body: An Orientation

Section: Chapter Questions

Problem 1RQ: The correct sequence of levels forming the structural hierarchy is A. (a) organ, organ system,...

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Which of the following is a correct sequence (in chronological order of occurrence) within excitation-contraction coupling? a. Synpatic vesicles fuse with the pre-synaptic membrane, Neurotransmitter binds to receptors in the post-synaptic membrane, Neurotransmitter diffuses across the synaptic cleft b. Neurotransmitter binds to receptors in the post-synaptic membrane, Synpatic vesicles fuse with the pre-synaptic membrane, Neurotransmitter diffuses across the synaptic cleft c. Synpatic vesicles fuse with the pre-synaptic membrane, Neurotransmitter diffuses across the synaptic cleft, Neurotransmitter binds to receptors in the post-synaptic membrane
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