Heart ‒ Section

Septum (Latin for “something that encloses”) refers to a wall or partition that divides the into chambers. The septa are physical extensions of the myocardium lined with endocardium. Located between the two atria is the interatrial septum. Between the two ventricles is a second septum known as the interventricular septum. It is substantially thicker than the interatrial septum, since the ventricles generate far greater pressure when they contract. The septum between the atria and ventricles is known as the atrioventricular septum. It is marked by the presence of four openings that allow blood to move from the atria into the ventricles and from the ventricles into the pulmonary trunk and aorta. Located in each of these openings between the atria and ventricles is a valve, a specialized structure that ensures one-way flow of blood. The valves at the openings that lead to the pulmonary trunk and aorta are known generically as semilunar valves.



*LICENSES AND ATTRIBUTIONS

CC licensed content, Shared previously, Heart Anatomy, Authored by: OpenStax College. License: CC BY: Attribution. License Terms: Download for free at:http://cnx.org/contents/Y5T_wVSC@3/Heart-Anatomy*

## Keywords
heart vein artery aorta pericardium cardiac muscle myocardium pulse circulation circulatory system capillaries blood