Explain how the heart muscle and the heart valves maintain a one-way flow of blood from the left atrium to the aorta

The left atrium has a higher pressure than the left ventricle due to the atrium filling with blood and contractingThis causes the atrioventricular valves (the mitral/bicuspid valve in the left side of the heart) to open This causes blood to flow into the left ventricle, causing the left ventricle's pressure to increase due to it filling with blood and contractingThe mitral/bicuspid valve closes to prevent blood flowing from the left ventricle to the left atrium (back flow)The ventricle now has a higher pressure than the aorta, as it has filled with bloodThe semi-lunar (aortic) valve opens and blood flows from the left ventricle to the aortaHigher pressure in the aorta compared to the ventricle, due to the ventricle not contracting anymore, causes the aortic valve to close and blood can now flow around the body