Chordae tendineae - wikipedia Chordae tendineae This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. ( July 2015 ) `` Heart strings '' redirects here. For other uses, see Heart Strings ( disambiguation ). Chordae tendineae The chordae tendineae are the tendons connecting the valves to the heart muscle Papillary muscles and chordae tendineae Details Identifiers Latin chordae tendineae cordis MeSH A07. 541.510. 240 Dorlands / Elsevier c_31 / 12236883 TA A12. 1.00. 023 FMA 76527 Anatomical terminology ( edit on Wikidata ) The chordae tendineae ( tendinous chords ), colloquially known as the heart strings, are cord - like tendons that connect the papillary muscles to the tricuspid valve and the mitral valve in the heart. Chordae tendineae are approximately 80 % collagen, while the remaining 20 % is made up of elastin and endothelial cells. Contents 1 Structure 1.1 Tendon of Todaro 2 Function 3 Additional images 4 See also 5 References Structure Tendon of Todaro The tendon of Todaro is a continuation of the Eustachian valve of the inferior vena cava and the Thebesian ring of the coronary sinus. Along with the opening of the coronary sinus and the septal cusp of the tricuspid valve, it makes up the triangle of Koch. The apex of the triangle of Koch is the location of the atrioventricular node. Function A medical illustration showing a cross section of the heart and lungs, chordae tendineae visible. During atrial systole, blood flows from the atria to the ventricles down the pressure gradient. Chordae tendineae are relaxed because the atrioventricular valves are forced open. When the ventricles of the heart contract in ventricular systole, the increased blood pressures in both chambers push the AV valves to close simultaneously, preventing backflow of blood into the atria. Since the blood pressure in atria is much lower than that in the ventricles, the flaps attempt to evert to the low pressure regions. The chordae tendineae prevent the eversion, prolapse, by becoming tense thus pulling the flaps, holding them in closed position. Additional images Papillary muscles and chordae tendineae Play media Ultrasound showing redundant chordae tendineae See also This article uses anatomical terminology ; for an overview, see Anatomical terminology. Cardiac cycle References ^ Jump up to : Karas, S. ; Elkins, R.C. ( 1970 ). `` Mechanism of Function of the Mitral Valve Leaflets, Chordae Tendineae and Left Ventricular Papillary Muscles in Dogs ''. Circulation Research. 26 ( 6 ) : 689 -- 96. PMID 5422929. doi : 10.1161 / 01. RES. 26.6. 689. Jump up ^ `` UOTW # 75 - Ultrasound of the Week ''. Ultrasound of the Week. 4 November 2016. Retrieved 27 May 2017. Anatomy of the heart General Surface base apex sulci coronary interatrial anterior interventricular posterior interventricular borders right left Internal atria interatrial septum pectinate muscles terminal sulcus ventricles interventricular septum trabeculae carneae chordae tendineae papillary muscle valves cusps atrioventricular septum cardiac skeleton intervenous tubercle Chambers Right heart ( venae cavae, coronary sinus ) → right atrium ( atrial appendage, fossa ovalis, limbus of fossa ovalis, crista terminalis, valve of inferior vena cava, valve of coronary sinus ) → tricuspid valve → right ventricle ( infundibulum, moderator band / septomarginal trabecula ) → pulmonary valve → ( pulmonary artery and pulmonary circulation ) Left heart ( pulmonary veins ) → left atrium ( atrial appendage ) → mitral valve → left ventricle → aortic valve ( aortic sinus ) → ( aorta and systemic circulation ) Layers Endocardium heart valves Myocardium Conduction system cardiac pacemaker SA node Bachmann 's bundle AV node bundle of His bundle branches Purkinje fibers Pericardial cavity pericardial sinus Pericardium fibrous pericardium sternopericardial ligaments serous pericardium epicardium / visceral layer fold of Left vena cava Blood supply Circulatory system Coronary circulation Coronary arteries Retrieved from `` https://en.wikipedia.org/w/index.php?title=Chordae_tendineae&oldid=798400462 '' Categories : Cardiac anatomy Hidden categories : Articles needing additional references from July 2015 All articles needing additional references Medicine infobox template using Dorlands parameter Talk Contents About Wikipedia Bosanski Deutsch Español Italiano Nederlands Português Tagalog Edit links This page was last edited on 1 September 2017, at 18 : 14. Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia ® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. About Wikipedia

Question: valve responsible for preventing backflow of blood from the lungs into the heart
Answer: chordae tendineae