Why does increased extracellular potassium around a neuron cause hyperexcitability?

💡 Explanation

Increased extracellular potassium reduces the potassium concentration gradient across the neuronal membrane, which reduces potassium efflux. Because the resting membrane potential is more depolarized, the neuron is closer to the threshold for firing an action potential; therefore, hyperexcitability results, rather than hyperpolarization.

• If a patient with a thyroid hormone synthesis deficiency begins taking an amiodarone medication, which consequence follows?
• Why does bone remodeling increase around a femoral hip implant after prolonged use, even when initial stress shielding was minimal?
• Why does hypertension commonly develop in elderly individuals with arteriosclerosis?
• Why does fever increase heart rate, even though cardiac output could initially meet metabolic demands?
• Which outcome occurs when bone marrow experiences failure?
• If a catheter-associated biofilm infection exhibits increasing resistance to antibiotics, which consequence is most likely regarding horizontal gene transfer within the biofilm community?