Osmosis video - Cardiac contractility

Contractility is the ability of the heart muscle to contract and thereby pump blood. Cardiac contractility is determined by the interaction between intracellular calcium concentration, and the myofilament cross-bridge cycling. The Frank-Starling mechanism is a key factor in determining cardiac contractility. This mechanism states that the more stretched (tensed) a heart muscle fiber is, the more calcium it will release from its stores, leading to increased contraction force.