If this cell were permeable only to K+, what would be the effect of reducing the extracellular K concentration from 5 to 2.5 millimolar? Intracellular (mM) Extracellular (mM) 140 K+ 5 K+ 12 Na+ 145 Na+ 5 CI- 125 CI- 0.0001 Ca++ 5 Ca++
Correct Answer: 19 millivolts hyperpolarization
Description: If a membrane is permeable to only a single ion Vm is equal to the equilibrium potential for that ion. In this hypothetical cell, EK+ = 88 millivolts. If the extracellular K+ concentration is reduced by half, EK+ = 61 x log (2.5/140) = 107 millivolts, (Hyperpolarisation of 19 millivolts.)
Category:
Physiology
Get More
Subject Mock Tests
Practice with over 200,000 questions from various medical subjects and improve your knowledge.
Attempt a mock test nowMock Exam
Take an exam with 100 random questions selected from all subjects to test your knowledge.
Coming SoonGet More
Subject Mock Tests
Try practicing mock tests with over 200,000 questions from various medical subjects.
Attempt a mock test now