ANATOMY

Detailed explanation-1: -Two large veins that lead into the heart are the superior vena cava and inferior vena cava.

Detailed explanation-2: -Your pulmonary arteries carry blood from your heart to your lungs. They’re the only arteries in your body that carry oxygen-poor (deoxygenated) blood.

Detailed explanation-3: -Final answer: Blood vessels that carry blood from organs to the heart are called veins.

Detailed explanation-4: -Veins. Veins carry blood toward the heart. After blood passes through the capillaries, it enters the smallest veins, called venules. From the venules, it flows into progressively larger and larger veins until it reaches the heart.

Detailed explanation-5: -From the innumerable cardiac capillaries, blood flows back to the cardiac chambers through venules, which in turn coalesce into the cardiac veins. Most cardiac veins collect and return blood to the right atrium through the coronary sinus; there may or not be a Thebesian valve covering the ostium of the coronary sinus.