It’s more pointed apex is directed toward the left hip and rests on the diaphragm, approximately at the level of the fifth intercostal space. Snugly enclosed within the inferior mediastinum, the medial cavity of the thorax, the heart is flanked on each side by the lungs. Approximately the size of a person’s fist, the hollow, cone-shaped heart weighs less than a pound. The modest size and weight of the heart give few hints of its incredible strength. The cardiovascular system can be compared to a muscular pump equipped with one-way valves and a system of large and small plumbing tubes within which the blood travels.
The heart separates the pulmonary and systemic circulations, which ensures the flow of oxygenated blood to tissues.
The valves of the heart secure a one-way blood flow through the heart and blood vessels. Contractions of the heart produce blood pressure, which is needed for blood flow through the blood vessels. Variations in the rate and force of heart contraction match blood flow to the changing metabolic needs of the tissues during rest, exercise, and changes in body position. The functions of the heart are as follows: Capillary Exchange of Gases and Nutrients.Intrinsic Conduction System of the Heart.Major Veins of the Systemic Circulation.Major Arteries of the Systemic Circulation.
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