The role of the Na+/K+ pump in cell membranes is to maintain the appropriate concentration gradients of sodium (Na⁺) and potassium (K⁺) ions across the plasma membrane. This active transport mechanism expels three Na⁺ ions from the cell while bringing in two K⁺ ions, thus establishing a membrane potential necessary for various cellular functions, including nerve impulse transmission and muscle contraction. The Na+/K+ pump plays a critical role in maintaining cellular homeostasis and overall cell viability.