GROSS ANATOMY

Detailed explanation-1: -The superior vena cava and inferior vena cava drain systemic venous blood into the posterior wall of the right atrium. The internal wall of the right atrium is composed of a smooth posterior portion (into which the vena cavae and coronary sinus drain) and a ridgelike, muscular anterior portion.

Detailed explanation-2: -Both the superior vena cava and inferior vena cava empty blood into the right atrium. Blood flows through the tricuspid valve into the right ventricle.

Detailed explanation-3: -Your superior vena cava is next to the right side of your sternum and goes into your right atrium, where all the oxygen-poor blood goes. Your inferior vena cava is a little longer. It starts where the right and left common iliac veins come together in your belly area and goes up into the right atrium of your heart.

Detailed explanation-4: -Deoxygenated blood returning from the body enters the heart through superior and inferior vena cavae, coronary sinus, and thebesian veins into the right atrium.