Current leakage from one cell depolarizes what?

Current leakage from one cell depolarizes what?

• A. The heart's nerve endings
• B. Another cell triggering an action potential
• C. The blood vessels
• D. The nucleus of the cell

Answer: (B)

Electric current spreading from one cardiac cell to its neighbors through gap junctions causes those neighboring cells to depolarize. When this passively brought-nearby membrane potential reaches the threshold, voltage-gated channels activate and an action potential is generated in the next cell, propagating the impulse through the heart. This electrotonic spread explains how a single depolarization can trigger neighboring cells to fire without external synaptic input. It doesn’t primarily involve nerve endings, blood vessels, or the nucleus, which are not driven by this direct intercellular depolarizing current in the same way.

Electric current spreading from one cardiac cell to its neighbors through gap junctions causes those neighboring cells to depolarize. When this passively brought-nearby membrane potential reaches the threshold, voltage-gated channels activate and an action potential is generated in the next cell, propagating the impulse through the heart. This electrotonic spread explains how a single depolarization can trigger neighboring cells to fire without external synaptic input. It doesn’t primarily involve nerve endings, blood vessels, or the nucleus, which are not driven by this direct intercellular depolarizing current in the same way.