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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 ...
Cardiac physiology or heart function is the study of healthy, unimpaired function of the heart: involving blood flow; myocardium structure; the electrical conduction system of the heart; the cardiac cycle and cardiac output and how these interact and depend on one another.
The bundle of His (BH) [1]: 58 or His bundle (HB) [1]: 232 (/ h ɪ s / "hiss" [2]) is a collection of heart muscle cells specialized for electrical conduction.As part of the electrical conduction system of the heart, it transmits the electrical impulses from the atrioventricular node (located between the atria and the ventricles) to the point of the apex of the fascicular branches via the ...
This is the strongest part of the fibrous cardiac skeleton. The upper chambers ( atria ) and lower ( ventricles ) are electrically divided by the properties of collagen proteins within the rings. The valve rings, central body, and skeleton of the heart consisting of collagen are impermeable to electrical propagation.
In vertebrates, the circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the body. [1] [2] It includes the cardiovascular system, or vascular system, that consists of the heart and blood vessels (from Greek kardia meaning heart, and Latin vascula meaning vessels).
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.
The myocytes of the heart (also called the myocardial fibers) are arranged in a general circumferential direction in the ventricles. In the left ventricle (LV), the fiber will change gradually in direction from a certain longitudinal-circumferential direction in the outer layer of the heart (epicardium) to another angulated direction almost orthogonal in the inner wall (endocardium), becoming ...
This function is so significant to normal functioning of the circulatory system that the cardiovascular centre is considered a vital centre of the medulla oblongata. [ 2 ] [ 3 ] Hormones like epinephrine and norepinephrine can affect the cardiovascular centre and cause it to increase the rate of impulses sent to the sinoatrial node , resulting ...