Cardiac Muscle Cannot Increase Its Strength by Recruitment Because

Multiple Choice

Cardiac muscle cannot increase its strength by recruitment because

A) The functional syncytium prevents activation of adjacent cells
B) Cells are coupled electrically through gap junctions, so all are activated every
contraction
C) The cardiac action potential lasts as long as the contraction
D) The [Ca²⁺] transient does not saturate cardiac TnC during most contractions
E) The bundle of His has no reserve capacity