Outline the physiology of excitation and conduction in nerve axons (60% of marks). List the factors which delay axonal conduction (40% of the marks).

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College Answer

The following points were expected to be outlined in this question
1. The resting membrane potential (RMP) and its physiological basis
2. How the RMP changes rapidly after a stimulus e.g. electrical or chemical and reaches a
threshold potential and an all or none action potential results
3. The ionic basis of the action potential
4. How the action potential is propagated
5. Factors that delay axonal conduction such as fibre size, myelination and electrolyte
abnormalities e.g. hypermagnesaemia.
Syllabus G2a
Reference: Power and Kam 1st edition p 6-9