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During craniocaudal folding, it assumes a position cranial to the developing heart at the level of the cervical vertebrae. [1] During subsequent weeks the dorsal end of the embryo grows much faster than its ventral counterpart resulting in an apparent descent of the ventrally located septum transversum. At week 8, it can be found at the level ...
The mediastinum (from Medieval Latin: mediastinus, lit. 'midway'; [2] pl.: mediastina) is the central compartment of the thoracic cavity.Surrounded by loose connective tissue, it is a region that contains vital organs and structures within the thorax, namely the heart and its vessels, the esophagus, the trachea, the vagus, phrenic and cardiac nerves, the thoracic duct, the thymus and the lymph ...
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 ...
T-tubules (transverse tubules) are extensions of the cell membrane that penetrate into the center of skeletal and cardiac muscle cells.With membranes that contain large concentrations of ion channels, transporters, and pumps, T-tubules permit rapid transmission of the action potential into the cell, and also play an important role in regulating cellular calcium concentration.
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]
Myocardial infarction; Other names: Acute myocardial infarction (AMI), heart attack: A myocardial infarction occurs when an atherosclerotic plaque slowly builds up in the inner lining of a coronary artery and then suddenly ruptures, causing catastrophic thrombus formation, totally occluding the artery and preventing blood flow downstream to the heart muscle.
A heart attack can cause arrhythmias, as well as permanent damage to the heart muscle. [25] Coronary ischemia resulting from coronary artery disease also increases the risk of developing heart failure. [10] Most cases of heart failure result from underlying coronary artery disease. [10]
A heart attack results from a sudden plaque rupture and formation of a thrombus (blood clot) that completely blocks blood flow to a portion of the heart, leading to tissue death . CAD can also result in heart failure or arrhythmias. Heart failure is caused by chronic oxygen deprivation due to reduced blood flow, which weakens the heart over time.