Which of the following ions is most likely to cross the plasma membrane of a resting neuron?
A) K⁺
B) Na⁺
C) Ca²⁺
D) Cl⁻

Question

Quizplus · Accepted Answer

The resting membrane potential of a neuron is primarily influenced by the ion concentrations of K⁺ and Na⁺. At rest, the neuron is more permeable to K⁺, meaning that it is more likely to cross the plasma membrane. Na⁺ is also able to cross the membrane, but to a lesser extent. Ca²⁺ is primarily involved in synaptic neurotransmitter release and is less likely to cross the membrane. Cl⁻ is negatively charged and would require an active transport mechanism to cross the membrane.

Which of the Following Ions Is Most Likely to Cross