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The heart is a muscular organ situated in the mediastinum.It consists of four chambers, four valves, two main arteries (the coronary arteries), and the conduction system. The left and right sides of the heart have different functions: the right side receives de-oxygenated blood through the superior and inferior venae cavae and pumps blood to the lungs through the pulmonary artery, and the left ...
The heart is cone-shaped, with its base positioned upwards and tapering down to the apex. [8] An adult heart has a mass of 250–350 grams (9–12 oz). [ 17 ] The heart is often described as the size of a fist: 12 cm (5 in) in length, 8 cm (3.5 in) wide, and 6 cm (2.5 in) in thickness, [ 8 ] although this description is disputed, as the heart ...
The Purkinje fibers have a fast inherent conduction rate, and the electrical impulse reaches all of the ventricular muscle cells in about 75 ms. Since the electrical stimulus begins at the apex, the contraction also begins at the apex and travels toward the base of the heart, similar to squeezing a tube of toothpaste from the bottom.
The right ventricle is triangular in shape and extends from the tricuspid valve in the right atrium to near the apex of the heart. Its wall is thickest at the apex and thins towards its base at the atrium. When viewed via cross section however, the right ventricle seems to be crescent shaped.
Coronary artery disease (CAD) or ischemic heart disease are the terms used to describe narrowing of the coronary arteries. [8] As the disease progresses, plaque buildup can partially block blood flow to the heart muscle. Without enough blood supply , the heart is unable to work properly, especially under increased stress.
The anatomy of the veins of the heart is very variable, but generally it is formed by the following veins: heart veins that go into the coronary sinus: the great cardiac vein, the middle cardiac vein, the small cardiac vein, the posterior vein of the left ventricle, and the oblique vein of Marshall.
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It is located on the diaphragmatic surface of the heart [1] [2] near the right margin. [2] It extends between the coronary sulcus and the (notch of [ 2 ] ) apex of the heart. It contains the posterior interventricular artery and middle cardiac vein .