The Immune System: Fighting Infection
Learning Objectives
Understand what the immune system is and what it does.
Be able to identify the 4 types of immune cells and an example of each.
Know what T-Cell is and its role in the body.
Know what antibodies are.
Your immune system is a group of cells, working together to defend you from all sorts of infection. These infectious villains are called pathogenic antigens.
Pathogenic Antigens (Figure 1) are the things that make you sick, like bacteria, viruses, and parasites.
To utterly destroy them, you have 4 different classes of murderous cells.
Let’s check them out!
First, there are the Phagocytes (Figure 2). This team includes Macrophage, Dendritic Cells, and Neutrophils. Phagocytes are soul eaters. They consume intruders and wear them like skins.
This lets other cells, like T-Cell know more about the enemy and the best strategy to kill them.
Then there are Antiparasitic cells (Figure 3). Basophils, Mastic Cells and Eosinophils are 3 types of Antiparasitic cells in your body. These cells kill what Phagocytes can’t: parasites. They are too big to eat.
But they can’t do everything in the spotlight! Someone has to kill the cells that are already infected. There’s a cell for that. They’re called Natural Killers(figure 4). These Ninja Assassins lurk in the shadows killing virus infected cells. This process is called “lysis” causing cells to undergo apoptosis. Instant cell death. Pretty cool! But they’re pretty general, and sometimes they screw up. Oh well.
Finally, there are Humoral Intercellular Cells (Figure 5). The HIC. This team of T and B Cells are your adaptive immune gang. They make sure that you have all the bits you need to defend against new attackers.
Check these guys out!
Helper T Cell reads the reports from phagocytes and decides what the other cells will do. It’s like the general commander.
B Cell makes antibodies based on T Cell’s specifications. These things mark intruding bacteria for death. Hard to hide when you’re glowing.
Cytotoxic Cells are a type of T Cell. But they don’t give the orders. Instead they selectively lyse cells.
And that’s your team! Together, these diverse cells defend your body from unwanted intruders; Keeping you healthy, one cell at a time.
infectious agents; they are what cause human sickness and disease.
Phagocytes are a type of immune cell that consumes bacterial intruders.
Antiparasitic cells target parasites that enter the body.
Natural Killers are immune cells that lyse infected or abnormal cells.
Humoral Intercellulars are immune cells that make up the adaptive immune system. They conduct the process of eliminating novel pathogens from the body.
Helper T Cells are a type of T cell . It reads data from Phagocytes and Natural Killers to decide how to defend against new invaders
B Cells are human cells that produce antibodies
Cytotoxic Cells are a type of T cell that lyses sells. But it is more selective and careful than Natural Killer Cells
