The wall of muscle separating the right and left atria is the interatrial septum. The interventricular septum separates the right and left ventricles.
As with many walls separating two chambers it is called the coronary/cardiac/heart septum. More acurately it is two separate septa the atrial septum and the ventricular septum.
the Endocardium.
The heart is divided into four chambers, the left atrium, the left ventricle, the right atrium, and the right ventricle. The two chambers in the upper portions of the heart are the atrium, and the two at the lower portions are the ventricles.
The upper chambers of the heart muscle include the
The upper two chambers of the heart are the right atrium or auricle, and the left atrium or auricle.
You are probably referring to mitral valve prolapse between the left atrium and ventricle.
The muscle that the heart is made out of is called the cardiac muscle. There are terms that represent heart attack and the heart muscle, but there isn't an exact scientific name for "heart". It's simply called heart.
Atrium
It is the valve that lies between the left atrium and the left ventricle in the heart.
The heart is divided into four chambers, the left atrium, the left ventricle, the right atrium, and the right ventricle. The two chambers in the upper portions of the heart are the atrium, and the two at the lower portions are the ventricles.
The upper chambers of the heart muscle include the
The type of muscle that is found in the right atrium is mainly the pectinate muscles. This is one of the four chambers of the heart.
the upper chambers of the heart are called the atria. (or atrium singular)
right atrium and left atrium
The areas of the heart are called atrium, and ventricals.
left atrium
The four major parts and division of the heart is the left and right atrium, and the left and right ventricle.
atrium
To return deoxygenated blood from the heart muscle to the right atrium.