Hi, need to submit a 1500 words paper on the topic The Circulatory System. In the most basic sense, the job of the circulatory system is to ensure that blood moves around inside a man’s body, supplying the nutrients needed in order for all the parts of the body to function properly. While the blood carries the oxygen and nutrients to the body, it also collects the carbon dioxide from the same. If there is no proper flow of blood, the organs in the body will not be able to function well.The circulatory system can be divided into three parts: pulmonary circulation, coronary circulation, and systemic circulation. The heart, lungs, and blood vessels are the major organs in each of these parts. Each individual part has its own unique process of blood circulation. “The successful circulation of each part results in an efficient distribution of blood throughout the body.” (Body)The central organ in the circulatory process is the heart. Composed of four chambers that are divided by a wall, this muscle pushes 2,000 gallons of blood containing oxygen and nutrients into the body. (Dowshen) The heart sends the blood out through its pumping motion. “It beats about 100,000 times a day, more than 30 million times per year, and about 2.5 billion times in a 70-year lifetime (Dowshen).” The speed of the heart’s pumps depends on the kind of activity the body does. It pumps slower when the body is at rest and faster when the body is in motion. This is because man uses up more energy when immersed inactivity. Energy comes from oxygen and oxygen comes from blood. The source of oxygen-rich blood is the heart.The four chambers of the heart can be grouped into two. namely, the upper and lower. The upper chamber or left and right atria receive the blood which has passed through the different organs in the body. On the other hand, the heart releases the blood to be used from the lower chamber or left and right ventricles.&nbsp. Two cardiac valves separate the bottom part of the heart from the blood vessels that allow blood to the rest of the body. The pulmonic valve is between the right ventricle and the pulmonary artery which goes to the lungs. The aortic valve is between the left ventricle and the aorta.