White blood cells

White blood cells are also known as leukocytes. These are the second most common cell type in the blood. When something harmful enters the body, you want to have a way to get rid of it. Also, if something goes wrong with one of your body cells when a cell is produced with some jacked-up DNA, well, you want to get rid of that too. White blood cells play a major role in the body’s defence mechanism, your immune system. Your immune system exists to protect the body from harmful stuff. And the white blood cells, there are a big part of those processes.

Difference between white blood cells and red blood cells: –

When we looked at how red blood cells were produced, we saw that at a certain point in the process, the differentiated cells got rid of organelles like the nucleus, the endoplasmic reticulum. And others so that they can be highly specialized for their function of delivering oxygen.

White blood cells are different in that there’s one category of cells in the blood that are complete cells. And by that, I mean they keep all their organelles that you see in a typical body cell, unlike red blood cells. They need DNA, they need mitochondria to generate energy, and they need to be able to create proteins like antibodies and many others.

So you will see a nucleus, you will see things like the.

The endoplasmic reticulum, but you’ll also see some other stuff, and we’ll talk about that in a little bit. Another difference between red and white blood cells is that white blood cells don’t have as long of a life span as red blood cells.

The average red blood cell will typically last around 120 days, but some white blood cells can be around for just a few hours and in some cases even minutes, depending on the type of infection they’re trying to get rid of. And one final difference between red and white blood cells is that they are. Way more red blood cells than white. While there can be around 5,000,000 red blood cells in just one microliter of blood, there are typically around 5 to 10,000 white blood cells in the same amount of blood.

That’s a huge difference.

Characteristics of white blood cells:-

Unlike erythrocytes, the red blood cells, leukocytes don’t spend all their time in blood vessels. Yeah, they travel along in those blood vessels scouting things out, and it uses these blood vessels to get to a specific destination.

But then they’re able to leave the blood vessels and enter the tissues directly via a process called diapedesis. They’re literally like squeezing in between the cells of blood vessels to get to where they need to be.

DIFFERENT TYPES OF LEUKOCYTES: –

Leukocytes can be divided into two main groups, granular leukocytes or granulocytes

This distinction has to do with what early scientists observed under the microscope after staining them in different ways. The three granular leukocytes are white blood cells that have granules inside of them, or at least the granules are transparent. These granules are tiny little containers. They’re vesicles that have stuff inside of them that have specific functions. The three granular leukocytes are the neutrophils. The agranular leukocytes are the monocytes and the lymphocytes. These cells are all produced in the red bone marrow, and they live for a very short period. It can be hours, or it can be days. If you compare that to the 120 days that red blood cells can last, when you look at them, you’ll notice something very peculiar. But their nucleus, they have these lobes. That’s another distinguishing characteristic.

The most common of the three types of granular leukocytes are neutrophils. They make up about 50 to 70% of the leukocytes. They’re called neutrophils because the granules show up clearly when you stand them with a stain that’s not acidic or basic, In other words, a neutral stain, that’s when you see them most clearly and they show up with kind of a light lilac colour.

when looking at the nucleus of these neutrophils, you’re going to see that they have anywhere from 2 to 5 lobes, depending on the age of the cell. The older it gets, the more lobes you’re likely to see, although keep in mind they don’t really stay around that long.

Neutrophils are part of the body’s primary line of defence against invading microorganisms.

Things like bacteria.

When there are bacteria in your body, they often release certain chemicals. One example would be cytokines. Now the neutrophils are there circulating in the blood Stream. When they detect that chemical, they’re attracted to it. So they go to the site of infection to find the bacteria. They will then basically eat up those bacteria, bringing them into the cell. This process is called phagocytosis. You know, have you ever played that game Pacman, where you have these little yellow plaque manns going around eating up these dots? Well, a picture that, except it’s not quite as fun because bacteria don’t taste fun, OK? And once the bacteria is.

In the cell, that’s when the granules go to work. Inside the granules of neutrophils, there are a number of substances. There’s an enzyme called lysozyme. Anytime you hear Lysol or lysis, think of something that breaks stuff down. Homolysis is breaking down red blood cells, in this case with lysozyme. The enzyme helps to break down bacterial cell walls. But we also have other stuff in there, things like hydrogen peroxide and defensins, basically these. Substances and others that are in the granules all work together to help break down those foreign invaders. You’ll see the granules combining with the ingested bacteria and basically digesting them. That’s how they do their work.

Now let’s talk about using uphill.

This makes up about 2 to 4% of the leukocyte population. They’re called eosinophils because the granules show up best when they’re stained with an acidic stain called eosin, hence the name eosinophils.

The nuclei also have loaves, but we’re talking about 2 to 3 lobes. Now in their granules, you will find substances that are involved in dealing with things like allergic reactions, parasitic worm infections, chronic inflammation and some autoimmune diseases.

So, when a person has your canophilia, meaning they’re higher than normal levels of Yoshino Phils and that’s in the blood, that that can be an indication that we’re dealing with one of those situations. And the last of the granular leukocytes are the basophils. You see their granules best when you use a basic stain. Their granules are on the larger side and they show up dark blue when they’re stained. These guys are very important in the local inflammatory response. They kind of intensify that response. They have things like histamines and other substances that are involved in things like that. So those were the granulocytes, the leukocytes with granules.

Now let’s talk about the granular, Leukocytes. First off, technically these still have granules, but they’re smaller and less visible. When they were first described, they couldn’t see the tiny granules, so they assumed that they were granular and the name kind of stuck. There are two types of agranulocytes, lymphocytes and monocytes. For the lymphocytes, we have three main types, the natural killer or NK cells, and the B&T cells, or the BNT lymphocytes, the natural killer cells.

Here’s how they work. Let’s say a cell gets infected with a virus. There are cells that will display fragments of that virus on their surfaces.

When the natural killer cells detect those abnormal structures in the cell, they will kill the cells with the virus inside them. It does this for cells infected with other viruses, cancer cells, and other cells that have weird proteins on their surfaces.

Now the B&T cells or the B&T lymphocytes, These bad boys are part of what we call specific immunity.

You see, nonspecific. Community is more general. There’s inflammation or an infection and other leukocytes will fight against them in a more general way. They don’t care as much what it is, they just want to get rid of it because it’s bad. With specific immunity, they’re fighting against specific infections or specific antigens. The B cells will produce antibodies to fight against that specific disease. This kind of specific immunity is called humoral immunity. T cells are also involved in specific. But at the cellular level, they’re gonna physically attack the entire cell, whether a foreign or a diseased cell.

Now, what’s cool about these B&T cells is that you can also get memory cells once there’s exposure to a specific illness. These memory cells are produced so that if the same pathogen ever enters your system again, the response is much quicker towards that particular disease. And that’s a beautiful thing. A lot of vaccines are based on this concept. You build up antibodies. Against a specific disease. And if you encounter that disease in the future, your body’s defences are ready to attack. OK, one more cell. These are the monocytes. These are larger cells and represent about two to 8% of the leukocytes. Once these monocytes leave the circulation and enter the tissues, they become macrophages. These can take in bacteria and other antigenic material by phagocytosis.

Do you remember that Pacman thing we spoke about?

That’s what we’re talking about here. Once they do that, they can help with getting rid of these. Substances. Either by doing some damage themselves or by recruiting other cells to help in the process.