The inflammatory response is a special type of innate immune response that will result in swelling of a region. So, if you, for example, fall and scrape your knee, let's say. Following that injury, platelets are going to form clots to seal off that site and prevent blood loss and also hopefully prevent any nasty stuff from getting into the wound. Now, those wounded tissues and the macrophages around them are going to release chemokines which are basically like a special type of cytokine that recruits cells to the infection site. Now, mast cells, which are a special type of immune cell, they are a type of granulocyte, their main job, or one of their main jobs, is to release histamine and this is a chemical signal that is going to constrict blood vessels in the area and that is going to not only reduce blood flow to the area but also prevent blood loss from the area. And part of the mast cell's job is also to signal the peripheral blood vessels to the infection site. So, you know, the local blood vessels are going to constrict. The blood vessels in the area around that are actually going to dilate and that combination of dilation and the chemokines that are being secreted is a major signal to neutrophils to mobilize, get there right away, and go to that infection immunosuppression site and release cytokines to recruit more immune cells. So hopefully, you can see that immune responses are sort of like escalations, there is an initial signal of help, a bunch of immune cells move in and, you know, they kind of shout help and more guys come in, and the signals and the response grows and grows. It's an escalation to recruit more and more cells to that area to deal with any pathogens or infection and, here I am trying to sort of cheat and use the same figure but pretend that this time, these are histamines and also cytokines and stuff. I don't have a great image unfortunately to illustrate the inflammatory response but it is a very similar process and this is really a theme you'll see throughout the immune system is cells secreting a signal to recruit other cells to that area to mount some type of immune defense. So that's all I have for this video. I'll see you guys next time. Stay healthy.