The Cardiovascular System Essay

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Composed of the heart, blood vessels, and blood, the cardiovascular system is the body system that carries out the tasks of pumping and transporting blood, oxygen, nutrients, and waste products, and other substances throughout the body. The cardiovascular system, however, would not be able to effectively complete these functions without help from what is sometimes referred to as the body’s hardest-working organ- the heart. Approximately the size of a fist, the heart is contains four chambers (the uppermost are called the atria and the lowermost are called the ventricles) and four valves. Additionally, the heart is surrounded by the pericardium, a structure that serves to protect the heart, keep the heart stabilized in the chest, and…show more content…
Composed of the heart, blood vessels, and blood, the cardiovascular system is the body system that carries out the tasks of pumping and transporting blood, oxygen, nutrients, and waste products, and other substances throughout the body. The cardiovascular system, however, would not be able to effectively complete these functions without help from what is sometimes referred to as the body’s hardest-working organ- the heart. Approximately the size of a fist, the heart is contains four chambers (the uppermost are called the atria and the lowermost are called the ventricles) and four valves. Additionally, the heart is surrounded by the pericardium, a structure that serves to protect the heart, keep the heart stabilized in the chest, and secrete lubricating fluid in order to prevent friction from generating as the heart rubs against other structures in the thoracic cavity. The outer wall of the heart is made up of three layers: the epicardium (the inner part of the pericardium), the myocardium (the muscular layer that contracts), and the endocardium (the innermost layer). Finally, the SA node (the body’s “pacemaker”), AV node, bundle of His, and purkinje fibers run the heart’s electrical conduction system, causing it to contract and relax, thus enabling it to pump blood. These structures make it possible the heart to perform its main function of circulating blood, which it does through two pathways known as the pulmonary and systemic circuits. The pulmonary circuit describes
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