The depolarization phase of the action potential of skeletal muscle cells ends when the ? a. Na+ activation gates close. B. Na+ activation gates open. c. Na+ inactivation gates close. d. Na+ inactivation gates open. e. K+ voltage gated channels open. What is the correct choice.
The depolarization phase of the action potential of skeletal muscle cells end?
(B) Na+ activation gates open.
When the voltage gated Na+ channels begins to inactivate, the membrane potential stops becoming more positive this results in the end of depolarization phase of action potential
The depolarization phase of the action potential of skeletal muscle cells ends when the ? a....
The peak of an action potential reaches +30 mV. This is because a. all of the available Na+ voltage activation gates are open b. all of the K+ voltage-gated channels open c. of the absolute refractory period d. of the decreased Na+ concentration gradient e. all of the available Na+ voltage inactivation gates are closed
CNCORA 6 of 10 > Action potentials in neurons involve opening and closing of voltage-gated Nat and K ion channels. Place the events of an action potential in order, starting and ending with a cell at its resting membrane potential. Resting state Return to resting state Answer Bank A graded potential brings the membrane to threshold potential. Fast Na+ and slow K* channels are activated. Nat rushes into the cell, causing membrane depolarization. K channels close slowly, resulting in hyperpolarization....
Which statements describe the action potential in cardiomyocytes (heart muscle cells)? Depolarization stimulates voltage-gated, slow calcium channels to open. The absolute refractory period can last for about 200 ms. Rapid sodium influx causes the membrane to rapidly depolarize. Repolarization occurs immediately after the initial depolarization.
Which of the following events does not occur during the depolarization phase of a skeletal muscle action potential? A. T-tubules depolarize B. troponin changes shape, moving tropomyosin off of actin's myosin binding sites C. Ca++ is released from the sarcoplasmic reticulum D. Ca++ channels in the axon terminal open
2. Neuron during an action potential: a. What triggers the first action potential (which ion)? b. What is the typical threshold potential of a neuron? c. The calculated equilibrium potential of Na+ (EN) is approx. +60mV (calculated). Explain how this is related to the rising phase of an action potential (depolarization). d. The calculated equilibrium potential of K+ (EK) is approx. -90mV. Explain how this is related to the falling phase (repolarization). e. Direction of Nation movement (influx/efflux). f. Direction...
The fixed pattern of changes in membrane potential during an action potential is coordinated by the sequential opening and closing of voltage-gated ion channels. Can you identify the status (open/closed) of the voltage-gated Na+ and K+ channels during each phase of an action potential? Drag the appropriate labels onto the graph to indicate the status (open or closed) of the voltage-gated Na+ and K+ channels during each phase of an action potential. Labels may be used once, more than once,...
For each phase of an action potential, indicate the ion channel most responsible for the membrane potential change that occurs during the phase. Action Potential Phases Ion Channels Depolarization phase Repolarization phase Hyperpolarization phase Voltage-gated potassium channels Chemically-gated sodium channels Chemically-gated potassium channels Voltage-gated sodium channels
During the propagation of an action potential, what would be the effect of a mutation in the voltage-gated Na+-channels that does not allow “inactivation” phase to occur, such that these channels go directly from open to closed conformations? a) The neuron with the mutant Na+ channels will start letting in calcium ions and generate a calcium-based action potential that is stronger than the sodium-based action potential. b) The neuron with the mutant Na+ channel will exhibit a reverse electrochemical gradient...
3. Many neurons contain "delayed K channels". Like voltage-gated Nat channels, these voltage-gated K+ channels open in response to a rise in membrane potential and then undergo inactivation. However, opening of the voltage-gated K channels lags behind opening of the voltage-gated Na channels. a) Why does neuronal function require the voltage-gated K channels to open more slowly than the voltage-gated Na channels? b) Compared to a neuron that lacks voltage-gated K channels, what differences would you expect in the shape...
QUESTION 7 What happens (immediately) if T-tubules blocked in skeletal muscle action potential increased an action potential blocked from progressing in fibril Myosin phosphatase in muscle O4(MP) activated d. inactivated QUESTION 8 Can be activated by stretch receptors (best answer only) a. Skeletal muscle Ob. smooth muscle Oc. myosin light chain phosphataso Od. A and B QUESTION 9 Action potential leads to activation of neurotransmitter in muscle answer true or false a true b. false c. not sure od silly...