23. Local anesthetics "block" the action potential and therefore do not allow "pain" information to proceed to the brain and spinal cord. In the presence of these molecules (local anesthetics) 'threshold' is essentially "ignored". The molecules most logically work by: a. Decreasing the intracellular [potassium] b. Blocking the opening of the voltage-gated potassium channels c. Decreasing the extracellular [sodium] d. Blocking the opening of the voltage-gated sodium channels

23. Local anesthetics "block" the action potential and therefore do not allow "pain" information to proceed to the brain and spinal cord. In the presence of these molecules (local anesthetics) 'threshold' is essentially "ignored". The molecules most logically work by: a. Decreasing the intracellular [potassium] b. Blocking the opening of the voltage-gated potassium channels c. Decreasing the extracellular [sodium] d. Blocking the opening of the voltage-gated sodium channels

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,...

See similar textbooks

Similar questions

8. Describe the differences between ionotropic and metabotropic signaling in the brain with respect to receptor properties and duration
9. Sodium Channels activate prior to Potassium channels. a. What would happen to the action potential if the potassium channels opened prior to sodium channels? b. Draw and describe what an action potential would look like; Label all axes.
3.single choice Which part of the nervous reflex is fatigable. A. synapse B. sensory receptors C. afferent neuron D. efferent neuron E. effector 4.multiple choice The factors that influence the AP conduction velocity on nerve fiber include A. thickness of the myelin shealth. B. myelinated or not C. diameter of the fiber D. temperature E. strength of the stimulation 5.single choice Which property could be destroyed by the local anesthetics procaine (普鲁卡因). A. physiological integrity B. structure integrity C. insulation D. infatigable 6.single choice Which of the following is not the chemical mediated signal transmission. A. gap junction B. neuro-muscular junction. C. hormone binding with the receptor on the target. D. classical synapse E. varicosity 7.single choice In the nerve reflex, the latency from the stimulation to the response is mainly dependent on A. the number of synapses in the central nervous system. B. the action potential…
27.
3. GABA is commonly introduced as the most prominent inhibitory neurotransmitter in our brains. However, scientists have discovered that GABA does not always lead to the inhibition of a postsynaptic neuron. Explain how this is possible for neurotransmitters more generally. In other words, describe how it is possible for the same neurotransmitter to cause either a depolarizing or hyperpolarizing effect at different postsynaptic synapses. Make sure you clearly explain the reasoning behind your answer.
1. What are an afferent neuron and efferent neuron? What are efferent components of the facial nerve and their actions? 2. Under certain circumstances, axons in the peripheral nervous system can regenerate after sustaining damage. Why is axonal regeneration in the central nervous system much less likely? 3. At a healthy myoneural junction, acetylcholine is responsible for stimulating muscle activity. What mechanisms are in place to prevent the continuous stimulation of a muscle fiber after the neurotransmitter is released from the presynaptic membrane?
7. You stimulate a presynaptic cell and record from the postsynaptic neuron of each pair. For each mutation below, describe the following: i) After the first stimulus, how does the excitatory postsynaptic potential (EPSP) you record from the postsynaptic neuron differ from the EPSP recorded from a wild-type animal? Does it increase, decrease, stay comparatively the same, or fail to be generated at all? ii) After five stimulations of the presynaptic cell in quick succession, how does the EPSP you record from the mutant animal differ from that in the same experiment on a wild-type animal? Explain your reasoning in each case. The mutations are as follows: 7A. Mutation of the voltage-gated Ca2+ channels of the presynaptic terminal. The mutant channels have a lower opening threshold.
7. Cell A is a glutamatergic neuron with a single synapse onto Cell B. Which of the following events would NOT result in an increased postsynaptic response in Cell B caused by an action potential in Cell A? a. Increase in the amount of glutamate released from Cell A b. Increase in the number of AMPA receptors on the surface of Cell B c. Increase in the number of GABA receptors on the surface of Cell B d. Addition of more synapses between Cell A and Cell B e. These would all increase the postsynaptic response
Benzodiazepines bind to & activate GABA receptors. This drug is: (SELECT 2) (a) Direct (b) Indirect (c) Agonist (d) Antagonsit
22. Blocking the opening of the voltage-gated potassium channels (after depolarization to threshold has occurred) would cause which of the following changes to the Action Potential? a. The neuron would never depolarize b. The neuron could never reach threshold c. The neuron would depolarize but never repolarize d. Blocking the potassium channels would decrease the intracellular [potassium].
4. What temporal relationship between presynaptic and postsynaptic spikes will result in: 4A. Long term potentiation (LTP)? 4B. Long term depression (LTD)? 4C. Neither LTP nor LTD?
9. In an inhibitory synapse, neurotransmitter binding to a receptor cause opening of __________ resulting in a hyperpolarizing event and reduces likelihood of AP generation. a. sodium ion channels b. potassium ion channels c. chloride ion channels d. a and b e. b and c