- [Narrator] Now that we know where the white blood cells are made, in the red bone marrow of your bones. Might as well get into the functionality of what they do. There are really two primary, two main functions, that your white blood cells will perform. First off, protection from infection. Your body can become infected in many different ways. It can become infected through bacteria. It can become infected through viruses. Or it can simply get other types of pathogens in there. So the white blood cells are meant to try and protect you from anything that might enter into your system. But besides protecting you for infection, they also will help control the inflammatory response. Your inflammatory response is going to happen whenever you get a nick, cut, scratch, simply a bruise. Inflammation is your body's way of initiating the healing process. So the white blood cells are going to help initiate this process by controlling the amount of inflammation. The more severe the injury, the more inflammation there'll be. The less severe the injury, the less inflammation there'll be. We have too many types of these white blood cells. They're referred to either as granular or agranular. Well, the granular types, they're called neutrophil, eosinophil and basophil, these three will all have little kind of specs or granules floating around in their surplasm, that's the liquid in the cell. While the agranular, the prefix a means without, so agranular or without granules, the lymphocytes and monocytes will no have any granules or specs floating around in the surplasm. So in their cell fluid, there's nothing floating around that looks like granules. So we have the two types, granular and agranular, and we break down the five different types of white blood cells into those two types. Let's start with the neutrphils. The neutrophil is a granular leukocyte. That means it's a white blood cell that's going to have granules inside the cell. It's the most common of all white blood cells. The neutrophils, since they are the most common, will be the first ones in the scene to fight an infection. Their specialty, engulfing bacteria, eating bacteria. Now, can they help out with other things? Sure. But they're really really specialized to destroy incoming bacteria. Your neutrophils. Eosinophils. Well, eosinophils are defending against larger parasites. They're specifically targeting worms. You're thinking worms, ew. Well, no, unfortunately sometimes there are parasitic worms that will try to infiltrate into your body. So these eosinophils are meant to detect any worms that have penetrated into your body and destroy these worms or any other large parasite. But the eosinophils have a secondary function also. They can help to lessen your allergic response. They will not get rid of it completely but they can definitely lessen it so it's not quite as problematic. Then we have the basophils. The basophils are the rarest of your white blood cells. So, WBC, white blood cell. They are very rare as far as behind the blood. Now, everyone has them, at least you're supposed to have them. Some people might have less than others. But they contain histamine in their granules. And these basophils have a lot of granules. Histamine, every heard that before? Maybe heard anti-histamine. Allergies. Well your allergies, usually trying to block the histamine. Block inflammation or swelling. Basophils contain histamine, which means they actually cause inflammation. So our neutrophils, eosinophils, basophils, the three types of granular leukocytes. Which leaves us with our last two. The agranular leukocytes. So first off, the monocyte. Monocytes are unique because they can actually leave the blood. That's not a typo. This are blood cells that can leave the blood. When they leave the blood they transform into macrophages. Now, macrophages are kind specialized. You can think of them as eating machines. They're going to eat any microorganisms, bacteria, viruses, other larger parasites. They're gonna eat any fragments, any particles. Maybe old broken down cells. So these monocytes are in the blood but can leave the blood, become macrophages and continue eating and digesting whoever is around. And the last of leukocytes, the lymphocyte. Lymphocytes are, again, part of the immune system but they play a pretty large roll because there's two different types of lymphocyte. You have your B lymphocytes and you have your T lymphocyte. Now, the T lymphocytes that's more traditionally what you heard of. Because T lymphocytes coordinate the immune response. They're going to help direct what cells go where. They're going to help direct when to basically move forward or hold. They are pretty much playing the coordinators of the entire battle between your body and foreign pathogens. While the B lymphocytes, they kind of take more a back seat. They won't necessary go out and fight pathogens. Instead, these B lymphocytes will end up making a cell called a plasma cell. The plasma cell makes your antibodies. That means the B lymphocytes eventually end up becoming antibodies, or lead to the making of antibodies. What do antibodies do? Antibodies are your body's way of detecting foreign particles. Cause pretty much every cell in your body has this marker on its surface, kind of like a fingerprint. It's meant to identify the cell as your own, part of your body. That means anything that is not part of your body, so hence an invader, or any other form, microorganism, will not have that marker. The antibodies detect that, can tag that cell for destruction. So antibodies are your body's way of figuring out what shouldn't be there, and they tag it and allow destruction. So we have the lymphocytes, a type of leukocyte. Monocytes, a type of leukocyte. So, again, leukocytes, those are the white blood cells. One type is a monocytes, another type is a lymphocytes.