Heart Muscle Contraction

Heart muscle contraction is how the heart pumps blood. It begins when electrical signals trigger muscle cells in the heart walls to contract simultaneously. These signals cause calcium ions to enter the cells, prompting the muscle fibers to slide past each other and tighten. This squeezing action pushes blood out of the heart's chambers—either into the lungs for oxygenation or to the rest of the body. After contraction, calcium is removed, and the muscle relaxes, ready for the next beat. This cycle repeats, maintaining steady blood flow essential for health.