A pathogen is typically used to refer to any microorganism that can cause disease which in its turn usually can spread from one person to another. In daily language pathogens are often just referred to as “germs”. In short pathogens are foreign, infectious microbes, that cause sickness and disease. Bacteria, viruses, fungi and protozoa are the most common types of pathogens and each affect the body in different ways.
Pathogens can enter a host through the nose, mouth, eyes or through a cut, or any other opening in the body.
In the case of bacteria, once it enters the body, it releases toxins that make the host ill.
Viruses on the other hand, enter into individual cells of the host’s body and then “hijack” the cell’s replication system, forcing it to produce a multitude of copies of the virus until the cell explodes which in its turn releases more viruses into the rest of the body and possibly to other hosts as well.
A few out of the thousands of fungi in existence may cause human diseases, from minor skin conditions all the way up to life-threatening diseases.
Protozoa are single cell organisms and some may cause disease through food poisoning or through transmission with the help of insect bites as in the case of malaria.
Luckily for us, the immune system is designed to fight pathogens and stop sickness. The first step of the immune response happens when the part of the pathogen called the antigen is recognized by white blood cells. This antigen can be thought of as a sort of identification for the pathogen, allowing the body to recognize and hunt it down! These antigens are also immensely important in immunology as well as more broad research in general.
Check out this video to learn more about what antigens are as well as how they work and how we use them in science! This series of videos which will follow are meant to give you all the puzzle pieces needed to understand the immune system as a whole and the concluding video in the series will cover that topic in detail!
UNTIL NEXT TIME!
