What prevents blood in the left and right mixing?

The left and right sides of the heart are separated by a muscular wall called the septum, which prevents blood from mixing between the two sides. The left side of the heart pumps oxygenated blood to the body, while the right side pumps deoxygenated blood to the lungs. Additionally, one-way valves in the heart ensure that blood flows in the correct direction, further preventing any mixing. This separation is crucial for efficient circulation and maintaining proper oxygen levels in the body.