Problem:

A patient is complaining of recent onset of muscle weakness in her right hand and arm that gets progressively worse throughout the day. Her right eyelid and the right side of her mouth also are drooping (ie. when she tries to smile) and her speech is slurred.

First a blood test is run to determine plasma electrolyte concentrations. Results show normal electrolyte concentrations.

Required:

Question 1: Explain what the effect would be on EK and on resting Vm if the ECF [K+] level was abnormally low?

Question 2: Explain how and why this change would affect the likelihood of AP firing? Be clear as to the direction of the equilibrium potential and membrane potential changes compared to normal. (3 pt, 100 words)

Question 3: Explain what the effect would be on ENa and on resting Vm if the ECF [Na+] level was abnormally high?

Question 4: Explain how and why this change would affect the likelihood of AP firing? Be clear as to the direction of the equilibrium potential and membrane potential change compared to normal. (3 pt, 100 words)

Please explain the results of all the answers.