Final answer:
The sequence of blood flow through the heart starts at the superior and inferior vena cava, moves through the right atrium and ventricle, into the lungs for oxygenation, and then back to the heart's left atrium and ventricle before being pumped throughout the body via the aorta.
Step-by-step explanation:
The correct sequence of blood flow through the heart, beginning with the superior and inferior vena cava, is as follows:
- Superior vena cava / Inferior vena cava - Veins that return deoxygenated blood from the body to the heart.
- Right atrium - Chamber that receives blood from the vena cavae.
- Tricuspid valve - Doorway between the right atrium and right ventricle.
- Right ventricle - Chamber that pumps the blood towards the lungs.
- Pulmonary valve - Gateway to the pulmonary artery.
- Pulmonary artery - Vessel carrying blood to the lungs for oxygenation.
- Lungs - Site of gas exchange where blood receives oxygen.
- Pulmonary veins - Vessels that return oxygenated blood to the heart.
- Left atrium - Chamber receiving oxygen-rich blood from the pulmonary veins.
- Mitral valve - Valve between the left atrium and left ventricle.
- Left ventricle - Chamber that pumps oxygenated blood to the body.
- Aortic valve - Valve leading to the aorta.
- Aorta - The main artery that distributes oxygenated blood to the body.
The blood exiting the systemic capillaries is low in oxygen concentration. It then flows through venules and veins before entering the superior and inferior vena cavae to be directed back to the right atrium of the heart, where the sequence begins.