Intraoperatively, the anatomy the the love is perceived from the ideal side of the supine patient via a median sternotomy incision. The structures at first seen from this perspective encompass the superior vena cava, right atrium, right ventricle, pulmonary artery, and aorta. Medial displacement that the ideal side of the heart exposes the left atrium and also right pulmonary veins. Medial rotation from the left exposes the left ventricle apex, left pulmonary veins, and left atrium. (See the images below.)

You are watching: The pointed inferior portion of the heart

Heart, anterior view.
Heart, posterior view.

The all at once shape and also position of the heart might vary follow to the loved one size and also orientation of each of the parts. For example, a big right ventricle may allow exposure of just a brief segment that aorta; this is since of the narrow boundaries of the center mediastinal space.

Right atrium

The premium vena cava and inferior vena cava drainpipe systemic venous blood right into the posterior wall surface of the best atrium. The internal wall of the appropriate atrium is written of a smooth posterior portion (into i beg your pardon the vena cavae and coronary sinus drain) and also a ridgelike, muscular anterior portion. The coronary sinus drains coronary venous blood right into the anteroinferior part of the appropriate atrium. The thebesian valve is located at the orifice that the coronary sinus. The limbus that the fossa ovalis is located on the medial wall of the right atrium and circumscribes the septum primum the the fossa ovalis anteriorly, posteriorly, and also superiorly. (See the picture below.)

Heart, sectioned view.

The right auricle is separated indigenous the right atrium by a shallow posterior upright indentation ~ above the appropriate atrium (ie, the sulcus terminalis) and, internally, by a upright crest (ie, the crista terminalis). The crista terminalis off the appropriate atrium into trabeculated and nontrabeculated portions.

Congenital anomalies of best atrial contents can be associated with clinically significant cardiac malformations. For example, in patients v tricuspid atresia, the eustachian and also thebesian valves might be therefore enlarged the they physically different the appropriate atrium right into 2 distinctive sections. Other variations incorporate juxtaposition of both atrial appendages and malpositioning the both appendages.

Left atrium

The 4 pulmonary veins drain into the left atrium. The flap valve that the fossa ovalis is situated on the septal surface of the left atrium. The appendage the the left atrium is continuously narrow and long; acknowledgment of this appendage is the many reliable way to identify the left atrium indigenous the appropriate atrium. The left atrial appendage is the only trabeculated structure in the left atrium because, uneven the appropriate atrium, the left atrium has actually no crista terminalis.

Right ventricle

The best ventricle receives blood from the appropriate atrium across the tricuspid valve, i beg your pardon is situated in the huge anterolateral (ie, sinus) part of the right ventricle. The ideal ventricle discharges blood right into the pulmonary artery across the pulmonic (semilunar) valve situated in the outflow street (infundibulum). The inflow tract (sinus) and also outflow street (infundibulum) that the appropriate ventricle room widely separated. Internally, the sinus area and infundibulum contain rough circuit trabeculations.

The septal portion of the best ventricle has actually 3 components: (1) the inflow tract, which support the tricuspid valve; (2) the trabecular wall, which typifies the internal appearance the the ideal ventricle; and also (3) the outflow tract, which itself is subdivided right into 3 components, namely, the conal septum, septal tape division, and trabecular septum. Of these 3 subdivisions, the conal septum is clinically far-reaching because it deserve to be malpositioned in patients through congenital disorders (eg, double outlet best ventricle).

Lateral come the conal septum, the parietal extension of the infundibular septum and also the infundibular fold make up the crista supraventricularis. Ventricular septal defects (VSDs) commonly occur in the area between the sinus and the outlet tract of the right ventricle. However, because the surface of the right ventricle is trabecular, tiny defects of the muscular section of the ventricular septum might be challenging to see.

The tricuspid valve is sustained by a large anterior papillary muscle, which occurs from the anterior complimentary wall and also the moderator band, and by several little posterior papillary muscles, which affix posteriorly to the septal band.

Left ventricle

The left ventricle receive blood native the left atrium via the mitral (ie, bicuspid) valve and also ejects blood across the aortic valve in the aorta. The left ventricle deserve to be separated into 2 major portions, namely, the huge sinus portion containing the mitral valve and the tiny outflow tract that supports the aortic (semilunar) valve. Inflow and outflow parts are closely juxtaposed, uneven in the appropriate ventricle, in i beg your pardon the tricuspid and pulmonic valves space widely separated.

See more: Although A Variety Of Different Styles Of Documentation, Writing Center: Documentation Styles

The totally free wall and apical half of the septum contain fine internal trabeculations. The septal surface ar is divided into a trabeculated section (sinus) and a smooth portion (outflow). The sinus area simply beneath the mitral valve is termed the inlet septum; the remainder the the sinus area is termed the trabecular septum. The outflow street is located anterior come the anterior mitral leaflet and also is component of the atrioventricular (AV) septum. Both the right fifty percent of the anterior mitral valve leaflet and the ideal aortic cusp attach to the septum. (In the ideal ventricle, just the septal tricuspid leaflet attaches come the septum.)

The left half of the anterior mitral leaflet is in direct, fibrous contact with the aortic valve at the aortic-mitral annulus. The conal septum that the appropriate ventricle is positioned the contrary the aortic valve. The mitral valve is supported by 2 large papillary muscle (ie, anterolateral, posteromedial) attached come the totally free wall. The anterior papillary muscle is attached come the anterior part of the left ventricular wall, and the posterior papillary muscle arises much more posteriorly indigenous the ventricle"s inferior wall. <1>