atriums

Atriums, or atrium as a singular, refers to two distinct concepts in everyday use: the atria of the heart and architectural atria. In anatomy, the atria are the two upper chambers of the heart. The right atrium receives deoxygenated blood from the superior and inferior vena cavae and the coronary sinus, while the left atrium receives oxygenated blood from the pulmonary veins. Blood moves from the atria into the ventricles through the atrioventricular valves—the tricuspid valve on the right and the mitral valve on the left. The atria are relatively thin-walled reservoirs that aid ventricular filling and house parts of the heart’s conduction system, including the sinoatrial node in the right atrium. The interatrial septum separates the two atria, with the fossa ovalis marking the remnant of the fetal foramen ovale.

In architecture, an atrium is a large open space inside a building, often spanning several stories and frequently covered by a glass roof. Atriums serve as light wells, social or circulation hubs, and organizing cores for interior routes. They are common in shopping centers, hotels, libraries, and office complexes, and contemporary designs emphasize daylighting, vertical openness, and views to surrounding spaces. Architectural atria may include balconies, plants, skylights, and integrated stair or escalator systems, influencing acoustics and climate within a structure. The term comes from Latin atrium, the main reception hall of a Roman house; in architectural usage, atriums is a standard plural, whereas atria is typically used for anatomical contexts.