Which ion is the primary conductor of the voltage-gated channel affected in HYPP?

Which ion is the primary conductor of the voltage-gated channel affected in HYPP?

• A. Sodium
• B. Potassium
• C. Calcium
• D. Chloride

Answer: (A)

The main idea is that HYPP affects a skeletal muscle voltage-gated sodium channel. When these channels open, sodium ions flow into the cell, causing the rapid depolarization that initiates muscle action potentials. A mutation in this sodium channel (SCN4A) alters sodium conductance, leading to abnormal excitability and episodes of weakness. So the ion that primarily passes through the affected channel is sodium. While potassium and calcium are important in muscle physiology, they are not the primary permeant through the voltage-gated channel implicated in HYPP.

The main idea is that HYPP affects a skeletal muscle voltage-gated sodium channel. When these channels open, sodium ions flow into the cell, causing the rapid depolarization that initiates muscle action potentials. A mutation in this sodium channel (SCN4A) alters sodium conductance, leading to abnormal excitability and episodes of weakness. So the ion that primarily passes through the affected channel is sodium. While potassium and calcium are important in muscle physiology, they are not the primary permeant through the voltage-gated channel implicated in HYPP.