Concept explainers
Ion regulation is a key feature of kidney function. What happens to the resting membrane potential of a neuron if extracellular K+ levels decrease? [p. 249]
To determine: The condition of resting membrane potential when the extracellular potassium ion level decreases.
Introduction: Resting membrane potential (RMP) describes the voltage difference across the cell membrane when the cell is at rest. It is a result of distribution of charged particles.
Explanation of Solution
At rest, a typical neuron has a resting potential of -70 millivolts. The RMP of living cells is determined by the K+ concentration gradient and the cell’s resting permeability to Na+, K+, and Cl-.
An alteration in either K+ concentration gradient or ion permeability changes the membrane potential. For example, if the extracellular K+ levels decrease, the resting membrane potential will be more negative. This change in cell’s membrane potential is known as hyperpolarization.
The lower K+ levels in the extracellular space causes hyperpolarization of the resting membrane potential.
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Chapter 19 Solutions
Human Physiology: An Integrated Approach (7th Edition)
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- Human Physiology: From Cells to Systems (MindTap ...BiologyISBN:9781285866932Author:Lauralee SherwoodPublisher:Cengage Learning