Heart Dissection Essay

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Introduction In this investigation, the external and internal structures of a sheep’s heart was examined and identified by dissection. The heart is a muscle that pumps oxygenated blood and nutrients throughout the body. A sheep’s heart has four chambers like most mammals. Two of those chambers are receiving chambers called the right and left atrium. The other two chambers are pumping chambers called the right and left ventricle. The efficiency in the cycle of blood depends on the sequential contraction of the atriums and ventricles. Whenever the atriums contract this is called the systolic phase and whenever the ventricles contract this is called the diastolic phase. These contractions ensure the regular flow of blood through the heart. The contractions occur one after another to make a heartbeat. The many valves such as the tricuspid and mitral valves control the flow of blood from each chamber. Blood flow through the heart starts when the right atrium takes the blood that flows in through the superior or inferior vena cava. The right atrium then fills with blood and pressure causes tricuspid valve to open. The blood then goes into the right ventricle where it contracts the blood into the pulmonary arteries. These arteries lead to the lungs where blood is then oxygenated. The oxygenated blood then flows from the lungs to the left atrium through the pulmonary veins. Due to pressure the mitral valve, which leads to the left ventricle, opens up and pushes the blood into the left ventricle. The left ventricle then contracts and forces the blood through the aorta, which provides the rest of the body with blood. Objectives Describe the appearance of the external and internal structures of a sheep’s heart Name the structure and function of a sheep’s heart Materials The materials needed in this dissection include: sheep’s heart, a dissecting tray, a
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