In turn, veins bring nutrient-depleted blood back to the heart. That's more than 21 road trips between New York and Los Angeles!Īrteries (along with smaller arterioles and microscopic capillaries) convey oxygen- and nutrient-rich blood to the body's tissues. Laid end-to-end, your body's blood vessels would extend about 60,000 miles. This extended network of stretchy tubes circulates blood throughout the body. While the heart and lungs are the largest organs of the circulatory system, the blood vessels are the longest.

The aortic valve is between the left ventricle and the aorta.Įach heart valve, except for the mitral valve, has three flaps (leaflets) that open and close like gates on a fence.

The mitral valve is between the left atrium and left ventricle.

The pulmonary valve is between the right ventricle and the pulmonary artery.

The tricuspid valve is situated between the right atrium and right ventricle.

These valves ensure that blood flows in only one direction, preventing backflow. Valves maintain direction of blood flowĪs the heart pumps blood, a series of valves open and close tightly.

The left side of the heart receives oxygen-rich blood from the lungs, then pumps blood out to the rest of the body's tissues, through the aorta. The right side of the heart collects oxygen-depleted blood and pumps it to the lungs, through the pulmonary arteries, so that the lungs can refresh the blood with a fresh supply of oxygen. The heart has a total of four chambers: right atrium, right ventricle, left atrium and left ventricle. Each side has an atrium (which receives blood as it enters) and a ventricle (from which blood is pumped out). The heart is divided into a right and left side, separated by a septum. On average, your heart will beat 100,000 times and pump about 2,000 gallons of blood each day. It pumps blood to all parts of the body through a network of blood vessels by continuously expanding and contracting.

Your heart is a strong, muscular organ situated slightly to the left of your chest.

Structure of heart download