What Is the Immune System for Kids | Learn all about how the body fights off bad germs

What is the immune system? Have you ever wondered about how your body protects itself from sickness and disease? Our body often takes care of itself without us even knowing what is happening. It does so through something called the immune system. Long ago, knights and other warriors wore armor to protect themselves from swords, spears, clubs, and other weapons when they were attacked. But the armor was only effective when the knights were wearing it. Similarly, the immune system acts as a protective armor to our bodies. But unlike the knight's armor, it works 24 hours a day, seven days a week. Besides being an invisible armor, what is the immune system exactly and how does it work? Simply put, the immune system is in charge of keeping the body safe from invading germs that try to attack it every day. These germs can be spread through the air from other people or by food. The immune system is made up of organs and cells just like the rest of your body and includes the skin, white blood cells, and the lymph system. This network works together with the circulatory system which controls the flow of blood throughout the body. Let's talk more about the super cool defense system and how it functions. Our first layer of defense from infection is our skin. It covers our bodies and acts as a guard against bacteria and other germs. The skin is the first place that germs attack and it is also a place where germs can spread. This is why it is important to keep our skin clean. Hand washing is one of the best ways to prevent the spread of germs. White blood cells are the watchers of the blood. There are three types of white blood cells. Neutrophils, macrophages, and lymphocytes. Each has a special mission to help keep your blood healthy and germ-free. Neutrophils move in the blood seeking out germs and bacteria that should not be there. Macrophages are the biggest blood cells. They move throughout the body to help keep it clean during the healing process. And lymphocytes are the white blood cells that attack infections. These amazing cells go after viruses and bacteria and seek to eliminate them. There are actually two different kinds of lymphocytes. T-cells and B-cells. T-cells find hidden germs or other unhealthy cells and destroy them. B-cells produce something called antibodies which are proteins produced to fight germs. The B-cell attaches itself to a germ which signals to the other white blood cells that needs to be destroyed. Helper T-cells are the ones that tell the B-cells to start making antibodies and also instruct killer T-cells to attack and destroy infected cells. And memory cells remember the germs that attack the body so that when the same germs come back again they are ready to fight These cells are like your own personal knights with permanent armor. Wow, white blood cells are so cool! The lymph system helps the lymphocytes get to where they need to go, picking up germs along the way and carrying them to lymph node glands. These glands collect and eliminate bacteria and Have you ever had a sore throat and one or both sides of your neck feel swollen? These are your lymph nodes doing their job and then when you are feeling better they shrink back to their normal size. We have talked a lot about the harmful germs in our bodies but not all germs are totally bad. In fact, some germs actually help make our immune system stronger. Remember when we talked about how memory cells help the body recall which germs have attacked the body so it can be ready for them if they come back? This is one of the ways germs can be important to our bodies because the exposure to germs prepares and strengthens our immune system against future attacks. This is how vaccines work and why they are so important. A vaccine is a weak virus that is injected into the body for the immune system to fight against. The weak virus has been changed so that you do not get sick from it but if the real disease or virus tries to attack the antibodies that were produced against the weak virus will destroy the real virus. Not all immune systems are the same though. Allergies are the result of the immune system attacking too much because it thinks that a safe food product or other item is a harmful germ and attacks it and sometimes the immune system mistakenly attacks healthy cells too. When this happens the person will have something that is called an autoimmune disease which is treated by medicine. Type 1 diabetes is an autoimmune disease that attacks the pancreas. Maybe you've heard of this or know someone that has it. Some people naturally have stronger immune systems than others but doing your best to keep it as healthy as possible is always a good idea. So what can you do? Do your best to reduce stress and get plenty of sleep. It is also important to eat healthy foods. Move your body and wash your hands. It might seem simple but every little bit helps. We have just learned of a lot of interesting facts about the immune system. Are you ready to review? True or false? Red blood cells are the watchers of the blood. False. White blood cells are the ones who do all that hard work. Name one of the ways that you can help keep your immune system strong. Get plenty of sleep. Reduce stress. Eat healthy. Move your body and exercise and wash your hands. Fill in the blank. Blank is the first layer of defense against germs. Skin. Great work all. No matter what you are doing, your immune system is always working. It is working when you get better after you get sick, when a cut heals, and when you do not catch the same disease over and over again. It works together along with other organs and systems in the body to keep you healthy and strong. And even though every immune system is not the same, it is still a vital part of our defense against disease. Our own system of knights always ready to go to battle. Hope you had fun learning with us. Visit us at learnbright.org for thousands of free resources and turnkey solutions for teachers and homeschoolers.