Which of the following might serve as a secondary pacemaker for the heart?
A) Both AV node and Purkinje fibers B) AV node
C) Purkinje fibers D) Neither AV node nor Purkinje fibers
B
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before initiating the voltage clamp, the membrane potential of the giant squid axon was resting at a present value of...
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The myometrium is the inner most layer of the uterus.
Answer the following statement true (T) or false (F)
X, Y, and Z are adjacent sensory receptors in the skin. During administration of the flu shot, a needle is inserted in the middle of Y's receptive field. All three receptors are activated. Which of the following is likely to be true?
A. The receptor potential in neurons X and Z will be more depolarized than in neuron Y. B. It won't be possible to discriminate which neuron's receptive field was stimulated at its center. C. The frequency of action potentials in the afferent pathway from neuron Y will be increased by excitatory interneurons projecting from the afferent pathways from neurons X and Z. D. The receptor potentials in all three neurons will achieve the same, average value. E. The frequency of action potentials in neuron Y will be greater than that in neurons X and Z.
Which of the following statements explains why sensations felt on the left side of the body are received by the right cerebral hemisphere?
A) There is no explanation for this occurrence. B) Axons of third-order neurons cross over to the opposite side of the CNS. C) First-order neurons cross over to the opposite side of the CNS. D) Axons of second-order neurons in a sensory pathway cross over to the opposite side of the CNS.