Boezem

Boezem is the Dutch term for the atrium of the heart, one of the heart’s two upper chambers that receive blood before it is pumped to the ventricles. There are two boezems: de rechter boezem (right atrium) and de linker boezem (left atrium).

The right atrium receives deoxygenated blood from the body via the superior and inferior vena cava and the coronary sinus. The left atrium receives oxygenated blood from the lungs through the pulmonary veins. Blood moves from the boezems to the ventricles through the atrioventricular valves: the tricuspid valve from the right atrium to the right ventricle, and the mitral valve from the left atrium to the left ventricle. The walls of the right atrium contain muscular ridges called pectinate muscles, while the left atrium is largely smooth-walled.

Anatomically, the two chambers are separated by the interatrial septum, which includes the fossa ovalis, a remnant of the fetal foramen ovale. The sinoatrial node (the natural pacemaker) is located in the right atrium, and the atrioventricular node lies near the septal area between the atria and ventricles, forming part of the heart’s conduction system.

Functionally, the boezems act as receiving reservoirs and contribute to ventricular filling, providing an atrial kick that aids the subsequent ventricular contraction, particularly during physical exertion or in certain cardiac conditions. Clinically, atrial fibrillation, atrial enlargement, and thrombus formation in the left atrial appendage are relevant considerations related to the boezems.