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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 muscle (also called heart muscle or myocardium) is one of three types of vertebrate muscle tissues, the others being skeletal muscle and smooth muscle. It is an involuntary, striated muscle that constitutes the main tissue of the wall of the heart .
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Add pericardium. Add papillary muscles and chordae tendinae. Add cardiac skeleton. Inferior vena cava more wide. Add aorta in bottom. Add source veins of superior vena cava. Brachiocephalic trunk more wide and separated. Added shadows. Left main pulmonary artery with its first division. 23:55, 2 January 2008: 650 × 650 (26 KB) Jakov
The bone or other structure the muscle is attached to that remains immobile during the action. The term "bone" is omitted from bone names. Insertion The attachment point of the muscle, on a bone or otherwise, that moves during the action. Artery The artery which supplies the muscle with blood. The term "artery" is included to avoid confusing ...
The heart's cardiac skeleton comprises four dense connective tissue rings that encircle the mitral and tricuspid atrioventricular (AV) canals and extend to the origins of the pulmonary trunk and aorta. This provides crucial support and structure to the heart while also serving to electrically isolate the atria from the ventricles. [1]
As with skeletal muscles the heart can increase in size and efficiency with exercise. [1] Thus endurance athletes such as marathon runners may have a heart that has hypertrophied by up to 40%. [ 3 ] : 1063–64 The difference between maximum and minimum cardiac outputs is known as the cardiac reserve and this measures the residual capacity to ...
The heart works by pumping blood around the body allowing oxygen, nutrients, waste, hormones and white blood cells to be transported. Diagram of the human heart. The heart is composed of two atria and two ventricles. The primary purpose of the atria is to allow uninterrupted venous blood flow to the heart during ventricular systole.