Heart
The hear t is a muscular organ in most animals. This organ pumps blood t hrough t he blood
vessels of t he circulat ory syst em.[1] The pumped blood carries oxygen and nut rient s t o t he
body, while carrying met abolic wast e such as carbon dioxide t o t he lungs.[2] In humans, t he
heart is approximat ely t he size of a closed fist and is locat ed bet ween t he lungs, in t he
middle compart ment of t he chest .[3]
Heart
The human heart
Details
System
Circulatory
Artery
Aorta,[a ] pulmonary trunk and right and left
pulmonary arteries,[b] right coronary artery, left
main coronary artery[c]
Vein
Superior vena cava, inferior vena cava,[d] right
and left pulmonary veins,[e] great cardiac vein,
middle cardiac vein, small cardiac vein, anterior
cardiac veins [f]
Nerve
Accelerans nerve, vagus nerve
Identifiers
Latin
cor
Greek
kardía (καρδία)
MeSH
D006321 (https://meshb.nlm.nih.gov/record/ui?
ui=D006321)
TA98
A12.1.00.001 (http://www.unifr.ch/ifaa/Public/E
ntryPage/TA98%20Tree/Entity%20TA98%20E
N/12.1.00.001%20Entity%20TA98%20EN.htm)
3932 (https://ta2viewer.openanatomy.org/?id=3
TA2
932)
Anatomical terminology
In humans, ot her mammals, and birds, t he heart is divided int o four chambers: upper left and
right at ria and lower left and right vent ricles.[4][5] Commonly t he right at rium and vent ricle are
referred t oget her as t he right heart and t heir left count erpart s as t he left heart .[6] Fish, in
cont rast , have t wo chambers, an at rium and a vent ricle, while most rept iles have t hree
chambers.[5] In a healt hy heart blood flows one way t hrough t he heart due t o heart valves,
which prevent backflow.[3] The heart is enclosed in a prot ect ive sac, t he pericardium, which
also cont ains a small amount of fluid. The wall of t he heart is made up of t hree layers:
epicardium, myocardium, and endocardium.[7]
The heart pumps blood wit h a rhyt hm det ermined by a group of pacemaker cells in t he
sinoat rial node. These generat e a current t hat causes t he heart t o cont ract , t raveling t hrough
t he at riovent ricular node and along t he conduct ion syst em of t he heart . In humans,
deoxygenat ed blood ent ers t he heart t hrough t he right at rium from t he superior and inferior
venae cavae and passes it t o t he right vent ricle. From here it is pumped int o pulmonary
circulat ion t o t he lungs, where it receives oxygen and gives off carbon dioxide. Oxygenat ed
blood t hen ret urns t o t he left at rium, passes t hrough t he left vent ricle and is pumped out
t hrough t he aort a int o syst emic circulat ion, t raveling t hrough art eries, art erioles, and
capillaries—where nut rient s and ot her subst ances are exchanged bet ween blood vessels and
cells, losing oxygen and gaining carbon dioxide—before being ret urned t o t he heart t hrough
venules and veins.[8] The heart beat s at a rest ing rat e close t o 72 beat s per minut e.[9]
Exercise t emporarily increases t he rat e, but lowers rest ing heart rat e in t he long t erm, and is
good for heart healt h.[10]
Cardiovascular diseases (CVD) are t he most common cause of deat h globally as of 2008,
account ing for 30% of deat hs.[11][12] Of t hese more t han t hree-quart ers are a result of
coronary art ery disease and st roke.[11] Risk fact ors include: smoking, being overweight , lit t le
exercise, high cholest erol, high blood pressure, and poorly cont rolled diabet es, among
ot hers.[13] Cardiovascular diseases frequent ly do not have sympt oms or may cause chest pain
or short ness of breat h. Diagnosis of heart disease is oft en done by t he t aking of a medical
hist ory, list ening t o t he heart -sounds wit h a st et hoscope, ECG, echocardiogram, and
ult rasound.[3] Specialist s who focus on diseases of t he heart are called cardiologist s,
alt hough many specialt ies of medicine may be involved in t reat ment .[12]
Structure
Development
Physiology
Clinical significance
History
Society and culture
Other animals
Additional images
Notes
References
Bibliography
External links
Retrieved from
"https://en.wikipedia.org/w/index.php?
title=Heart&oldid=1117919412"
Last edited 11 days ago by CactiStaccingCrane