HeartFrom Wikipedia, the free encyclopediaThis article is about the internal organ. For other uses, seeHeart (disambiguation).Heart

The heart is located at the center of the chest. The muscle mass is greater on the left side and the apex of the heart is pointed slightly to the left.

Drawing of a human heart

Details

Latincor

Greekkarda ()

SystemCirculatory

ArteryRight coronary artery,left coronary artery,anterior interventricular artery

VeinSuperior vena cava,inferior vena cava, rightpulmonary veins, left pulmonary veins

NerveAccelerans nerve,Vagus nerve

Identifiers

MeSHA07.541

TAA12.1.00.001

FMA7088

Anatomical terminology

Normal heart sounds

MENU0:00Normal heart sounds as heard with astethoscope

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Theheartis amuscularorganin humans and other animals, which pumpsbloodthrough theblood vesselsof thecirculatory system.[1]Blood provides the body withoxygenandnutrients, and also assists in the removal ofmetabolic wastes.[2]The heart is located in the middle compartment of themediastinumin thechest.[3]In humans, other mammals and birds the heart is divided into fourchambers: upper left and rightatria; and lower left and rightventricles.[4][5]Commonly the right atrium and ventricle are referred together as theright heartand their left counterparts as theleft heart.[6]Fish in contrast have two chambers, an atrium and a ventricle, while reptiles have three chambers.[5]In a healthy heart blood flows one way through the heart due toheart valves, which preventbackflow.[3]The heart is enclosed in a protective sac, thepericardium, which also contains a small amount offluid. The wall of the heart is made up of three layers:epicardium,myocardium, andendocardium.[7]The heart pumps blood through both circulatory systems. Blood low in oxygen from thesystemic circulationenters the right atrium from thesuperiorandinferiorvena cavaeand passes to the right ventricle. From here it is pumped into thepulmonary circulation, through thelungswhere it receives oxygen and gives off carbon dioxide. Oxygenated blood then returns to the left atrium, passes through the left ventricle and is pumped out through theaortato the systemic circulationwhere the oxygen is used andmetabolizedtocarbon dioxide.[2]In addition the blood carries nutrients from theliverandgastrointestinal tractto various organs of the body, while transporting waste to the liver andkidneys.[citation needed]In the healthy organism eachheartbeatcauses the right ventricle to pump the same amount of blood into the respiratory organ as the left ventricle pumps to the body.Veinstransport blood to the heart and carry deoxygenated blood - except for the pulmonary andportal veins.Arteriestransport blood away from the heart, and apart from the pulmonary artery hold oxygenated blood. Their increased distance from the heart cause veins to have lowerpressuresthan arteries.[2][3]The heart contracts at a restingrateclose to 72 beats per minute.[2]Exercisetemporarily increases the rate, but lowersresting heart ratein the long term, and is good for heart health.[8]Cardiovascular diseases(CVD) are the most common cause of death globally as of 2008, accounting for 30% of deaths.[9][10]Of these more than three quarters followcoronary artery diseaseandstroke.[9]Risk factors include:smoking, beingoverweight, little exercise,high cholesterol,high blood pressure, and poorly controlleddiabetes, among others.[11]Diagnosis of CVD is often done bylisteningto theheart-soundswith astethoscope,ECGor byultrasound.[3]Specialists who focus on diseases of the heart are calledcardiologists, although many specialties of medicine may be involved in treatment.[10]Contents[hide] 1Structure 1.1Heart wall 1.2Chambers 1.3Coronary circulation 2Development 3Physiology 3.1Blood flow 3.2Electrical conduction 3.3Heart rate 3.4Heart sounds 4Clinical significance 4.1Diagnosis 4.2Assessment 4.3Treatment 4.4Surgery 5History 5.1Ancient 5.2Pre-modern 5.3Modern 6Society and culture 6.1Symbolism 6.2Food 7Other animals 7.1Double circulatory systems 7.2The fully divided heart 7.3Fish 7.4Invertebrates 8Additional images 9References 10External links