Welcome to learning about the circulatory system! This amazing network in your body works like a highway system, with your heart as the central pump. The heart sends oxygen-rich blood through arteries to your brain and lungs, while veins bring blood back to the heart. Your brain controls everything, and your lungs add fresh oxygen to the blood.
The heart is divided into four chambers. The two upper chambers are called atria, and the two lower chambers are called ventricles. The right side of the heart pumps blood to the lungs, while the left side pumps blood to the rest of the body. Watch how the heart beats rhythmically to push blood through your circulatory system.
Inside your lungs are millions of tiny air sacs called alveoli. When you breathe in, oxygen from the air passes through these alveoli into your bloodstream. At the same time, carbon dioxide waste from your blood passes into the alveoli to be breathed out. This exchange happens continuously, providing fresh oxygen to every cell in your body.
Your brain is the master controller of your circulatory system. It constantly monitors oxygen levels in your blood and adjusts your heart rate accordingly. When you exercise, your brain signals your heart to beat faster and your lungs to breathe deeper. The brain stem controls these automatic functions, sending signals through the spinal cord to keep your circulation working perfectly.
Here's how blood flows through your complete circulatory system. The heart pumps oxygen-poor blood to the lungs where it picks up fresh oxygen. This oxygen-rich blood then travels to your brain and other organs, delivering the oxygen they need. The blood, now carrying waste products, returns to the heart to start the cycle again. This amazing process happens continuously, about 70 times per minute, keeping every cell in your body alive and healthy.