ANSWER:
The four major blood vessels in the heart are:
1. Aorta: The aorta is the largest artery in the body and carries oxygenated blood from the left ventricle of the heart to the rest of the body. It distributes oxygen-rich blood to various organs and tissues.
2. Pulmonary Arteries: The pulmonary arteries carry deoxygenated blood from the right ventricle of the heart to the lungs for oxygenation. There are two pulmonary arteries, one for each lung.
3. Superior Vena Cava: The superior vena cava is a large vein that carries deoxygenated blood from the upper body and arms back to the right atrium of the heart. It collects blood from the head, neck, upper limbs, and upper chest.
4. Inferior Vena Cava: The inferior vena cava is another major vein that carries deoxygenated blood from the lower body and legs back to the right atrium of the heart. It collects blood from the abdomen, pelvis, and lower limbs.
These four major blood vessels play crucial roles in the circulation of blood within the heart and throughout the body, ensuring the delivery of oxygen and nutrients to various tissues and the removal of waste products.