Left atrioventricular opening

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Left atrioventricular opening
Latin	ostium atrioventriculare sinistrum
Gray's	subject #139 533
Dorlands/Elsevier	o_09/12601891

The left atrioventricular opening (mitral orifice) is placed below and to the left of the aortic orifice.

It is a little smaller than the corresponding aperture of the opposite side.

It is surrounded by a dense fibrous ring, covered by the lining membrane of the heart, and is guarded by the bicuspid or mitral valve.

[edit] External links

• left+atrioventricular+orifice at eMedicine Dictionary

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.

v • d • e Anatomy of torso, cardiovascular system: heart Structures atria (interatrial septum, musculi pectinati) • ventricles (interventricular septum, trabeculae carneae, chordae tendinae, papillary muscle) • valves • cusps Regions base • apex • grooves (coronary/atrioventricular, interatrial, anterior interventricula, posterior interventricular) • surfaces (sternocostal, diaphragmatic) • borders (right, left) Right heart (vena cavae, coronary sinus) → right atrium (atrial appendage, 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)  → 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 pericardium: fibrous pericardium • serous pericardium (pericardial cavity, epicardium/visceral layer) • pericardial sinus myocardium • endocardium • cardiac skeleton (fibrous trigone, fibrous rings) Conduction system Cardiac pacemaker • SA node • AV node• bundle of His • Purkinje fibers