Final answer:
Blood circulates through the heart in two main loops: the pulmonary circulation that involves the lungs and the systemic circulation that delivers oxygenated blood to the body. Oxygen-poor blood enters the heart, is sent to the lungs for oxygenation, returns to the heart, and is then pumped to the rest of the body. This cyclical process repeats to maintain vital functions.
Step-by-step explanation:
Blood Flow Through the Heart
The journey of blood through the heart and body consists of two main circuits: the pulmonary circulation and the systemic circulation.
Pulmonary Circulation
- Oxygen-poor blood returns to the right atrium through the superior and inferior vena cava.
- From the right atrium, it moves to the right ventricle, which pumps it to the lungs via the pulmonary arteries.
- In the lungs, blood releases carbon dioxide and takes in oxygen.
- Oxygen-rich blood then flows back to the left atrium of the heart via the pulmonary veins.
Systemic Circulation
- From the left atrium, blood travels to the left ventricle.
- The left ventricle pumps the oxygen-rich blood into the aorta, the body's main artery.
- This highly oxygenated blood is then distributed throughout the body via arteries, reaching every cell where it is needed for cellular respiration.
- Once the oxygen is delivered and carbon dioxide is collected, the now oxygen-poor blood returns to the heart to begin the process again.
The cardiovascular circulation is an efficient system ensuring that oxygenated blood is constantly delivered to the tissues and organs, and waste products like carbon dioxide are expelled from the body.