Answer Happy

(a) Describe with suitable diagrams (transmembrane potential and ionic conductances) the sequence of events during a nerve or muscle action potential. Indicate typical values for the resting transmembrane potential, maximum value of the transmembrane potential and duration of the action potential. (b) Using the core conductor model to describe a single fibre, derive an expression for the relationship between the transmembrane current density and the second spatial derivative of the transmembrane potential. State all assumptions that you make. ©) Show how the core conductor model may be combined with the Hodgkin-Huxley action potential model to obtain an expression for a propagating action potential that may be solved as a function of both time and space. Draw the equivalent electrical circuit for the fibre membrane, taking care to label and define each component.