Human Anatomy & Physiology
1st Edition
ISBN: 9780805382952
Author: Erin C. Amerman
Publisher: PEARSON
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Textbook Question
Chapter 11, Problem 3AYKA
Albert accidentally ingests the poison tetrodotoxin from the pufferfish, which you know blocks voltage-gated
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After discussing his case with his physician, he learned that he had probably been the victim of pufferfish poisoning. The active toxin in the tissues of this fish is a chemical called tetrodotoxin (TTX). Tetrodotoxin is in a class of chemicals known as neurotoxins because it exerts its effects on neurons. The specific action of tetrodotoxin is that it blocks voltage-gated sodium ion channels.
Define the following phrases and terms associated with the signs and symptoms of Dr. Westwood’s TTX poisoning:
diaphoresis
motor dysfunction
paresthesias
cyanotic
hypoventilating
bradycardia
gastric lavage
oxygen saturation
As mentioned in the case description, tetrodotoxin is a molecule that blocks voltage-gated sodium ion channels. What is a voltage-gated sodium ion channel and what is its function?
When nerve cells are at rest, there is an unequal amount of positive and negative charges on either side of a nerve cell membrane. This charge difference creates an electrical potential.…
Use this illustration to place these events in the order they occur during synaptic communication:
Column A
Column B
a. Voltage gated sodium channels carry the action potential
to the synapse by allowing the influx of sodium ions.
1.
1
2
b. An increase in calcium levels triggers vesicle release.
3.
3
c. Sodium enters the post-synaptic cell, causing it to
depolarize.
4.
4
d. Sodium influx at the synapse activates voltage gated
5.
calcium channels which allow calcium ions to enter the
presynaptic neuron.
6.
6.
e. Neurotransmitters are released into the synaptic cleft.
f. Ligand-gated ion channels are opened by the
neurotransmitters.
2.
Dendrotoxins, produced by the mamba snakes (Dendroaspis), are inhibitors of the voltage-gated K+ channels. What phase of the action potential would this toxin affect? How would it affect ion permeability during this phase? How would ion movement be affected?
Chapter 11 Solutions
Human Anatomy & Physiology
Ch. 11.1 - What are the organs of the CNS?Ch. 11.1 - Prob. 2QCCh. 11.1 - Describe the sensory, integrative, and motor...Ch. 11.1 - 4. What are the differences between the somatic...Ch. 11.1 - How does the somatic motor division of the PNS...Ch. 11.2 - What are the functions of the cell body,...Ch. 11.2 - What are the structural differences between...Ch. 11.2 - What are the functional differences between...Ch. 11.2 - What are the functions of astrocytes?Ch. 11.2 - Prob. 5QC
Ch. 11.2 - Prob. 6QCCh. 11.2 - 7. What is the function of the myelin sheath?
Ch. 11.2 - How does the myelin sheath differ in the CNS and...Ch. 11.2 - Are neurons more likely to regenerate in the CNS...Ch. 11.2 - Prob. 10QCCh. 11.3 - 1. What is the resting membrane potential?
Ch. 11.3 - Prob. 2QCCh. 11.3 - What two factors generate the resting membrane...Ch. 11.3 - Prob. 4QCCh. 11.3 - Prob. 5QCCh. 11.3 - In and around the axon, where is the higher...Ch. 11.3 - What is the resting membrane potential, and what...Ch. 11.3 - Prob. 8QCCh. 11.3 - Prob. 9QCCh. 11.3 - Prob. 10QCCh. 11.3 - What takes place during the depolarization phase...Ch. 11.3 - 7. What must be reached in order for...Ch. 11.3 - 8. What takes place during the repolarization and...Ch. 11.3 - 9. What are the absolute and relative refractory...Ch. 11.3 - 10. How do local potentials and action potentials...Ch. 11.3 - Which is useful for long-distance signaling, and...Ch. 11.3 - 12. How is an action potential propagated down an...Ch. 11.3 - Prob. 18QCCh. 11.4 - What are three locations where presynaptic axons...Ch. 11.4 - Define synaptic transmission.Ch. 11.4 - Prob. 3QCCh. 11.4 - Prob. 4QCCh. 11.4 - Prob. 5QCCh. 11.4 - Prob. 6QCCh. 11.4 - Prob. 7QCCh. 11.5 - Prob. 1QCCh. 11.5 - Prob. 2QCCh. 11.5 - Prob. 3QCCh. 11.5 - Prob. 4QCCh. 11.5 - Prob. 5QCCh. 11.6 - 1. Why are neurons organized into neuronal...Ch. 11.6 - Prob. 2QCCh. 11.6 - 3. What mechanisms stabilize neural circuits?
Ch. 11 - Which of the following statements about the...Ch. 11 - 2. Regulation of heart rate, blood pressure, and...Ch. 11 - Match each type of neuroglial cell with its...Ch. 11 - Prob. 4CYRCh. 11 - Prob. 5CYRCh. 11 - Prob. 6CYRCh. 11 - 7. Fill in the blanks: The _______is the period of...Ch. 11 - With respect to the condition of action...Ch. 11 - 9. Identify the following as properties of...Ch. 11 - The trigger for exocytosis of synaptic vesicles...Ch. 11 - Match the following neurotransmitters with their...Ch. 11 - 12. Which of the following is not a method by...Ch. 11 - 13. A ________is characterized by multiple input...Ch. 11 - Mark the following statements as true or false. If...Ch. 11 -
15. Mark the following statements as true or...Ch. 11 - Sequence the following list of events of a...Ch. 11 - 16. Mark the following statements as true or...Ch. 11 - 1. A drug that blocks channels in neurons does so...Ch. 11 - Prob. 2CYUCh. 11 - What conditions must be met for an axon to...Ch. 11 - 4. Explain how an action potential is propagated...Ch. 11 - Prob. 1AYKACh. 11 - 2. During a surgical procedure, an...Ch. 11 - Albert accidentally ingests the poison...Ch. 11 - 4. Albert, the patient in question 3, takes the...Ch. 11 - Predict the effect that tetrodotoxin would have on...Ch. 11 - Explain what would happen if depolarization of the...
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Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, biology and related others by exploring similar questions and additional content below.Similar questions
- An undisclosed drug (Drug A) is a drug that can block voltage-gated K+ channels when being introduced into the bloodstream. Explain the effects of Drug A on the action potentials produced by a neuron. If Drug A could be applied selectively to a presynaptic neuron that releases an excitatory neurotransmitter, analyse how would it alter the synaptic effect of the neurotransmitter on the presynaptic cell. Remark: The word count limit (250 words only), no less than 100 wordsarrow_forwardThe graph shows a tracing of membrane potential change during the course of an action potential in a typical neuron. Predict the effect of exposure to the following neurotoxins. Briefly explain how you would expect the action potential to change in the presence of each toxin and why. A toxin produced by puffer fish which specifically binds to voltage-gated sodium channels and blocks the flow of sodium ions through the channel. A toxin found in scoprion venom which slows the closure of voltage-gated sodium channel inactivation gates. Assume that the cell is normally brought to threshold by an electrical stimulus applied to it, so that any change is due only to the presence of the toxin Precise values for voltage and duration are not important, just a general trend in how the action potential may differ from the typical trace shown is expected.arrow_forwardAcetylcholine is an excitatory neurotransmitter that is responsible for initiating muscle movement. Consider the scenario where a mouse was bitten by a snake that injected venom into their circulatory system. The venom has an inhibitory effect on the reuptake of acetylcholine from the synaptic cleft. Explain how the mouse’s body would respond to the venom as well as the venoms effect at the cellular level.arrow_forward
- The venom of many cobras contains a potent neurotoxin that binds to ligand-gated Na+ channels,causing them to open. Unlike ACh, which binds to and then rapidly unbinds from ligand-gated Na+ channels, the neurotoxin tends to remain bound to ligand-gated Na+ channels. How does this neurotoxin affect the nervous system’s ability to stimulate skeletal muscle contraction? How does it affect the ability of skeletal muscle fibers to respond to stimulation?arrow_forwardCan you explain to me why choice E is the correct answer and break down why the other options are false?Select the choice option that is TRUE regarding the absolute and relative refractory periods of the action potential (AP). A. The absolute refractory period occurs when the activation gate of voltage gated sodium channel closes at the peak of the AP B. The relative refractory period occurs when the inactivation gate of voltage gated sodium channels closes at the peak of the AP C. The relative refractory period occurs when the activation gate of voltage gated potassium channels opens at the peak of the AP D. The absolute refractory period may be overcome if enough excitatory stimulation is applied to the neuronal membrane E. All of the choice options are FALSE regarding the absolute and relative refractory periods of the AParrow_forwardDescribe the action potential in terms of the different functional states of the voltage- gated Na+ membrane channels (Note: there are three states)arrow_forward
- What is the difference between inactivate and closed Na+ channels?Explain how a salty flavor is transduced into an action potential. Describe each step in an action potentialarrow_forwardActivation of the beta-gamma subunit associated with the Go protein complex would lead to what outcome? 1.closing of presynaptic Ca++ channels 2.postsynaptic depolarization 3.postsynaptic hyperpolarization 4.increased production of cAMParrow_forwardDescribe the three states of voltage-gated Na+ channels in neurons.arrow_forward
- The compound tetraethylammonium (TEA) blocks the voltage-gated changes in potassium permeability that occurs during an action potential. After administration of TEA, what changes would you expect in the action potential?arrow_forwardPlease answer question 3 parts A and Barrow_forwardPredict the effect of a reduced extracellular concentration of Na+ on themagnitude of the action potential in an electrically excitable cell.arrow_forward
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