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Heart muscle)
Myocardium is the muscular tissue of the heart. Other tissues are the endocardium (inner lining, effectively a specialised endothelium) and the pericardium (a connective tissue layer around the heart).
The myocardium is composed of specialized cardiac muscle cells with an ability not possessed by muscle tissue elsewhere in the body. Cardiac muscle, like other muscles, can contract, but it can also conduct electricity, like nerves.
The blood supply of the myocardium is by the coronary arteries. If these arteries are occluded by atherosclerosis and/or thrombosis, this can lead to angina pectoris or myocardial infarction.
Certain viruses lead to inflammation of the myocardium, or myocarditis.
Failure of the heart to contract properly (for various reasons) is termed heart failure, generally leading to fluid retention, edema, pulmonary oedema, renal insufficiency, hepatomegaly, a shortened life expectancy and decreased quality of life.
| Cardiovascular system - Heart - edit
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| atria (interatrial septum, musculi pectinati) | ventricles (interventricular septum, trabeculae carneae, chordae tendinae, papillary muscle) | valves
base | apex | grooves (coronary/atrioventricular, interatrial, anterior interventricula, posterior interventricular) | surfaces (sternocostal, diaphragmatic) | borders (right, left)
right heart: (vena cavae, coronary sinus) → right atrium (auricle, fossa ovalis, limbus of fossa ovalis, crista terminalis, valve of the inferior vena cava, valve of the coronary sinus) → tricuspid valve → right ventricle (conus arteriosus, moderator band/septomarginal trabecula) → pulmonic valve → (pulmonary artery and pulmonary circulation)
left heart: (pulmonary veins) → left atrium (auricle) → mitral valve → left ventricle → aortic valve (aortic sinus) → (aorta and systemic circulation)
pericardium (sinus) | epicardium | endocardium | myocardium | cardiac skeleton (fibrous trigone, fibrous rings)
conduction system: cardiac pacemaker | Purkinje fibers | bundle of His | SA node | AV node
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| skeletal muscle/general: epimysium, fascicle, perimysium, endomysium, muscle fiber, myofibril
sarcomere (a, i, and h bands; z and m lines), myofilaments (thin filament/actin, thick filament/myosin, elastic filament/titin), tropomyosin, troponin
neuromuscular junction, intrafusal muscle fibers, extrafusal muscle fiber, motor unit, muscle spindle, sliding filament mechanism
myoblast, satellite cells, sarcoplasm, sarcolemma, sarcoplasmic reticulum, T-tubule
cardiac muscle: myocardium, intercalated disc
smooth muscle: calmodulin, vascular smooth muscle
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de:Herzmuskel
es:Miocardio
eu:Miokardio
fr:Myocarde
it:Miocardio
nl:Hartspierweefsel
nn:Myokard
pt:Miocárdio
ru:Миокард
