Left atrioventricular opening

Left atrioventricular opening
Details
Latin	ostium atrioventriculare sinistrum
Identifiers
Gray's	p.533
Dorlands /Elsevier	o_09/12601891
TA	A12.1.04.002
FMA	9335
Anatomical terminology

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.

References

This article incorporates text in the public domain from the 20th edition of Gray's Anatomy (1918)

Anatomy of the heart

General

Surface

Internal

atria interatrial septum musculi pectinati sulcus terminalis 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 (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

Endocardium	heart valves

Myocardium	conduction system: cardiac pacemaker SA node AV node bundle of His Purkinje fibers

Pericardial cavity	pericardial sinus

Pericardium	fibrous pericardium sternopericardiac ligaments serous pericardium epicardium/visceral layer fold of left vena cava

Blood supply

Index of the heart

Description	Anatomy Physiology Development

Disease	Injury Congenital Neoplasms and cancer Other Symptoms and signs eponymous Blood tests

Treatment	Procedures Drugs glycosides other stimulants antiarrhythmics vasodilators