Figure 1 shows the action potential graph recorded from a rat neurone and the potential changes obtained from the rat neurone when the concentration of potassium ([K*]out) and calcium ([Ca²+]out) are varied extracellularly in the bathing solution. (i) In the resting state, is the neuronal permeability to potassium more than, less than or equal to that of the permeability to calcium? Explain your answer. (ii) Vm 'The calcium ion concentrations are lower inside the cell than outside.' Justify this statement based on the graphs and the Nernst equation assuming the temperature is at 25 °C. Vm 30 0 -30 30 0 -30- 50 AP overshoot [K+ lout 100 150 time (msec) 30 RP Figure 1 0 -30 AP overshoot RP 200 250 AP overshoot [Ca²+ lout RP

Figure 1 shows the action potential graph recorded from a rat neurone and the potential changes obtained from the rat neurone when the concentration of potassium ([K*]out) and calcium ([Ca²+]out) are varied extracellularly in the bathing solution. (i) In the resting state, is the neuronal permeability to potassium more than, less than or equal to that of the permeability to calcium? Explain your answer. (ii) Vm 'The calcium ion concentrations are lower inside the cell than outside.' Justify this statement based on the graphs and the Nernst equation assuming the temperature is at 25 °C. Vm 30 0 -30 30 0 -30- 50 AP overshoot [K+ lout 100 150 time (msec) 30 RP Figure 1 0 -30 AP overshoot RP 200 250 AP overshoot [Ca²+ lout RP

Human Physiology: From Cells to Systems (MindTap Course List)

9th Edition

ISBN:9781285866932

Author:Lauralee Sherwood

Publisher:Lauralee Sherwood

Chapter4: Principles Of Neural And Hormonal Communication

Section: Chapter Questions

Problem 1RE: Conformational changes in channel proteins brought about by voltage changes are responsible for...

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