The Circulatory System

Every part of the body is essential to its function. The heart is one of the most essential organs in the body; it essentially gives us life. Without the heart, the blood in our bodies would not be able to run its course through our veins and arteries. Without the heart, fresh oxygenated blood could not be produced for the many components of the body that depend on it. Without the heart, a body could not be kept alive.
The heart is an organ that pumps blood through the body, supplies oxygen and nutrients to the tissues, and removes waste and carbon dioxide from the body. It is the key component of the circulatory system. The heart’s weight ranges from about 8 to 12 ounces and is located in the center of the thoracic cavity, specifically the
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Blood circulates through the heart in two ways. They are identified as the pulmonary circuit and the systemic circuit. The pulmonary circuit is simply the movement of blood from the heart, to the lungs, and back up to the heart again. Deoxygenated blood leaves the right ventricle of the heart and runs through the pulmonary artery; from here, the blood is pumped through the right atrium and into the right ventricle. The blood continues its course and travels through the lungs. While in the lungs, the deoxygenated blood releases its carbon dioxide and picks up oxygen through the process of respiration. Finally, the newly oxygenated blood returns to the left atrium of the heart, completing the pulmonary circuit. Opposite of the pulmonary circuit is the systemic circuit. This circuit carries blood to all the nooks and crannies of the body excluding the lungs. In the systemic circuit, the newly oxygenated blood, from the pulmonary circuit, leaves the body through the left ventricle to the aorta, and enters the arteries and capillaries where it supplies the body 's tissues with oxygen. The now oxygen-depleted blood returns back to the heart, completing the circuit. The pulmonary and systemic circulations are on a continuous loop, pumping blood to and from the heart. The heart is critical to the body for survival because it pumps the blood and nutrients that the …show more content…
The human body is covered by the epithelial tissue. This tissue also lines all cavities and makes the glands. The second tissue is the connective tissue which connects the structures of the body, provides support and holds the organs together. The third type of tissue is the muscular tissue. This tissue provides movement and heat. The nervous tissue is the last type of tissue and its function it to respond to the environment by detecting, processing, and coordinating information. The heart is a fist-sized organ made of muscle tissue. It contains two types of cardiac muscle cells: cardiomyocytes and pacemaker cells. The cardiomyocytes make up the bulk, or 99%, of the cells within the atria and ventricles. These cells must be able to shorten and lengthen their fibers in the proper form during the beating of the heart. These cells are connected by certain discs that allow a rapid response to the impulses of action potential sent out by the pacemaker cells. Pacemaker cells make up the remaining 1% of cardiac muscle cells. These are generally smaller than cardiomyocytes and have myofibrils that give the pacemaker cells their limited contractibility. Pacemaker cells work almost like neurons. They fire rhythmic impulses that are received by the cardiomyocytes thus causing the heart wall to contract. These cells set the pace for blood pumping. Cardiomyocytes and pacemaker cells are unique only to the heart.
In conclusion, the heart

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