Blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium.
heart
the superior and inferior vena cava into the right atrium
Veins carry deoxygenated blood back the heart.
maybe your question goes this way..."how does oxygen enter the blood from the lungs?"Two types of blood vessels carry blood throughout our bodies: The arteries carry oxygenated blood (blood that has received oxygen from the lungs) from the heart to the rest of the body. The blood then travels through the veins back to the heart and lungs, where it receives more oxygen.
It enters the arteries.
Venous return (VR) is the flow of blood back to the heart. Arteries takes oxygenated blood away from the heart to the body and veins Cary the blood back to the heart and lungs for disposal of CO2 among other things.
Through the right ventricle =D
De-oxygenated blood is dark red. Oxygenated blood is bright red. Both enter the heart- the former enters the right heart; the latter enters the left heart.
heart
heart
Veins carry deoxygenated blood back the heart.
Depleted blood enters and leaves the right side of the heart.
Actually it is the Left Atrium
somewhere
It flows through the pulmonary vein toward the heart.
The pulmonary vein enters the left atrium of the heart.
Deoxygenated blood return form the body to the heart via the Superior and Inferior Vena Cavas, which join together to enter the Heart's Right Atrium.
The lungs, I the alviolies.
Right Atrium.