Cardiac septa

The different cardiac septa are the anatomical structures that separate the chambers of the heart. The main septa are:

• Interatrial septum: This separates the right and left atria, described with the three main components of the atrial septum, with the fossa ovalis (formed by the septum primum) and its muscular rim (septum secundum). The sinus venosus is adjacent but not a true component of the atrial septum.

• Interventricular septum: This separates the right and left ventricles. It consists of a muscular portion (further divided into inlet, trabecular, and outlet portions) and a membranous portion.

• Atrioventricular septum: the part of the membranous part of the interventricular septum, located above the root of the septal cusp of the mitral valve, between the right atrium and the left ventricle.