Ventricles Contract

The heart is crucial to all walks of life and although the heart is approximately the size of a fist, it plays a vital role in life. The heart is broken down into four chambers, four valves, and different arteries and veins along with it. The atrium are located on the upper half of the heart, known as the right and left atria. On the bottom half of the heart, the chambers are known as the right and left ventricles. The atria work together simultaneously and then the ventricles will work in a synchronized manner. The atria will contract and then the ventricles will in tandem. Although it seems simple enough, the heart is one extraordinary organ that has a mind of its own. It all starts with the sinoatrial (SA) node in the upper right corner

From there the impulse travels along the left and right bundle branches in the septum of the heart all the way to the Purkinje fibers. At this point, the blood has flowed from the atria to the ventricles. The impulse signal in the Purkinje fibers is allowing the apex of the heart to contract. Allowing the apex to contract first allows for the heart to work more efficiently. As soon as the apex contracts, the AV valves close and the walls of the heart begin to contract which pull the papillary muscles. The papillary muscles have chordae tendineae that attach themselves to the atrioventricular valves. These chordae tendineae work to try and prevent AV valve prolapse. When the pressure is great enough in the ventricles to overcome the resting blood on the other side of the arteries, the blood will be pushed out of the ventricles and will be passed through the semilunar valves. The right ventricle pushed blood through the pulmonary semilunar valve, and the left ventricle will push blood through the aortic semilunar valve. When the ventricles have expelled as much blood as they can and the pressure returns to a lower level the heart will begin to relax allowing the semilunar valves to close. Excess blood that does not get pushed along the arteries will remain on the artery side of the semilunar