what is the innate immune system?

the innate immune system is a very important part of our body as it contains our first and second defenses against pathogens. it is considered a non-specific immune response because it isn’t tailored to any specific pathogens and is more a defense to stop/kill most pathogens from entering the body using a vaguer method than the adaptive immune system.

for example, let’s say per say a pathogen gets pass the skin, which is our first line of defense (but it can be any physical barrier for the pathogens), through a cut or in the nose or something and but let’s say in this example it is through the nose. when a cell is damaged by pathogen that got in, the cell releases histamine to basically say to the body that a pathogen has gotten in. the body responds to the histamine by increasing blood flow to the damaged tissues, this is called vasodilation. this first step in inflammatory response (this is our second line of defence).

Normally after the first step may you start feeling hot but you could lead to redness, pain, heat, or swelling depending on how the pathogen got in. the body starts to clot the wound to isolate the pathogen. this is the second step in the inflammatory response. Phagocytes come to the area and neutrophils and macrophages engulf the pathogen and this causes inflammation. the dendritic cells collect the dead pathogens with long tentacles and show them to immune system. while the natural killer cells kill the infected cells. This is the third step of the inflammatory response.

The last step is that the macrophages die forming puss.