Upper chamber of the heart that receives blood?

• A. Atrium
• B. Ventricle
• C. Aorta
• D. Pulmonary Artery

Answer: (A)

Upper chambers receive blood. The heart has atria in the top that act as receiving rooms for blood coming back to the heart, and ventricles in the bottom that pump blood out. The right atrium collects deoxygenated blood from the body via the superior and inferior vena cavae and the coronary sinus, while the left atrium collects oxygenated blood from the lungs via the pulmonary veins. These chambers have thinner walls because they operate at lower pressures, simply filling before the blood moves on. Blood flows from the atria into the ventricles through the atrioventricular valves during relaxation of the heart. In contrast, the pumping chambers are the ventricles: the right ventricle sends blood to the lungs via the pulmonary artery, and the left ventricle sends blood to the rest of the body via the aorta. The aorta and pulmonary artery themselves are arteries, not chambers. So the upper chamber that receives blood is the atrium.