Circulatory System for Kids | Learn all about how blood travels through the body

The circulatory system for kids. What is like a freeway or highway that stretches for more than 60,000 miles in your body? It is the circulatory system. Let's learn more about it and why it is the most important system in the human body. Put your hand on your heart for a second. Do you feel it beating? Every time your heart beats, blood is sent all around your body. This is part of the circulatory system. This special system is responsible for bringing blood to all areas of the body, fighting disease, healing injuries, and transporting nutrients and oxygen throughout the body. And the heart is, well, the heart of the whole operation and the muscle. Get it? Because the heart is a muscle. Without the heart, the circulatory system would not work. The circulatory system circulates or transports blood to and from the heart and also carries oxygen and nutrients to every cell in the human body. This oxygen comes from the air you breathe into your lungs. So, the circulatory system is many different parts of your body, all working together to make sure that every cell is getting what it needs to thrive. There are two main parts to the circulatory system, the heart and the blood vessels. Blood vessels include arteries, veins, and capillaries. Let's start with the heart. Located between the lungs, just to the left, is the heart. We already mentioned that it pumps blood into the rest of the body, but here is an interesting fact. The heart beats around 60 to 100 times per minute, depending on lots of factors, including age and health. And your heart may beat faster or slower, depending on what your body needs at the time. For example, when you are playing outside and running around with friends, your heart beats faster because your body needs more oxygen. Right now, you may be sitting still, so your heart is beating slower, because it does not need as much oxygen. Did you know that the heart has different sections called chambers? These four chambers are divided by valves and collect and pump blood. They also control the direction the blood flows in the body. Two of the heart's chambers, called the left and right ventricles, are located in the bottom of the heart and pump blood out. The other two chambers, the left and right atria, which are found in the upper part of the heart, receive blood or take it in. The valves open for the blood to empty from the chambers and then close so that the blood does not flow in the wrong direction. The valves make sure the rest of the body gets the right amount of blood. When you hear the sound of your heart or feel it beat, that is the result of the opening and closing of the valves as your blood pumps through your body. Pretty awesome, right? The other main part of the circulatory system is the blood vessels, which include the arteries, veins, and capillaries. What do these vessels do? Glad you asked. Arteries are the thickest blood vessels. They carry blood away from the heart. This blood is enriched with oxygen as it is sent through the largest artery in the body, called the aorta, and then circulated through the rest of the body. Then veins carry blood back to the heart. Veins are thin and not as flexible as arteries, but they are larger in diameter. Capillaries are tiny blood vessels that carry blood between the arteries and veins, connecting them together. Here is an interesting fact. Capillaries are so small, they are only about one cell thick. They also deliver nutrients and oxygen to all of the body cells. Capillaries also remove carbon dioxide and other waste products from the body. Now that we know how the circulatory system works, let's talk about what's inside your blood. Have you ever heard of bone marrow before? Bone marrow produces red blood cells, white blood cells, and platelets. These ingredients plus plasma are what make up your blood. Red blood cells carry oxygen throughout the body by carrying a chemical called hemoglobin, which gets oxygen from the air you breathe. Here is another interesting fact. Hemoglobin is what makes your blood red in color. White blood cells protect your body when it gets sick. There are not as many white blood cells as there are red, but there are different kinds of white blood cells. Granulocytes help wounds heal and prevent infections by killing germs. T-cells and B-cells are lymphocytes that produce antibodies to attack bacteria or viruses. B-cells also prevent germs from causing problems in the future. Last, monocytes fight and destroy bacteria by surrounding and attacking it. Platelets are cells that help clot or stop bleeding when you have a cut or other injury. Plasma is a yellowish liquid that carries proteins, nutrients, and hormones to the rest of the body. It is mostly made up of water that comes from what you eat and drink. Plasma also carries waste away from your cells, directing it to the kidneys, which are the organs that remove this waste from the blood. All of these things work together to form the circulatory system. Okay, that was a lot of new information. Let's review to see what you remember. True or false, the heart has four chambers. True, they are the left and right ventricles and the left and right atria. Fill in the blank. Blank blood cells protect the body from getting sick. White, which organ is at the heart of the circulatory system. The heart. Nicely done, friend. The circulatory system is a vital part of keeping your body alive and healthy. The next time you are taking a swim or running around, remember how your heart and blood vessels are working together to make sure you get the oxygen and nutrients it needs to be strong. Hope you had fun learning with us. Visit us at learnbright.org for thousands of free resources and turnkey solutions for teachers and homeschoolers.