I am a virus, which is also a pathogen. My main job/goal is to enter your body and then stimulate an immune response.
First I am going to try to infiltrate through the nose of this human.
Mucus and nose hair are going to attempt to keep me out . They are apart of the first line of defense in the immune system and is also a non-specific defense. Skin is also apart of this first line. A specific defense, for example, would be if this body developed immunity to specific pathogens or other foreign things.
I'm in! Now I have to get through the 2nd line of defense.
The 2nd line of defense includes macrophages ,which is a phagocyte,and inflammatory response. It assists with allergic and inflammatory responses. This second line of defense also releases Histamine. Histamine is what makes blood vessles dialate near injuries.
The T cell is apart of the cell mediated response. It destroys infectious cells and releases perforin, which creates a hole in the cell membrane.
The B cell is apart of the humoral response. It creates antibodies.
Lastly, is the 3rd line of defense. This line includes B and T cells, which are specific types of white blood cells.They are antibodies.