The Innate Immune System

Innate is a defense you are born with and is nonspecific. Its job is to detect, deflect, and destroy. The innate immune system deals with stuff we were born with such as: external barricades like skin and mucus membrane, as well as, internal defenses like phagocytes, natural killer cells, and antimicrobial proteins. The first step in the innate immune system stats with the physical barrier—your skin, which keeps out vengeful microorganism. As longs as the skin doesn’t get beat up too much. But if so no worries, we also have our mucous membrane as a physical barrier which lines the cavities that are exposed to the outside world. These physical barriers also offer chemical protection as well, acid from skin, mucin that forms mucus, microbiota

Which is where defense tact’s rise known as fever, chemical signals, and inflammation. These allow infectious invaders to be found and attacked. But the first defensive cells on site are the phagocytes which gathers intruders and eats them to rid of their existence. When a macrophage sees a new bacterium, it grabs it using cytoplasmic extensions and completely engulfs it, digesting it, and spitting the rest out. Then we have natural killer cells, which can kill your own cells if they are infected because a lack of MHC1. But if a cell is infected and a natural killer cell notices it, it will then poke holes (lyse) which is caused by the complement system. Now if the virus is flooding into the tissue an inflammation response it will be

In the event of injury certain mast cells in the connective tissues send out histamine molecules. That cause vasodilation, developing redness and heat at the site of infection. The heat helps bump up the cells metabolic rate so that they can repair quickly. While histamine and other chemicals of inflammation increase the permeability of blood vessels. Then triggering capillaries to release protein-rich fluids. Then because of this swelling takes place, the leaked proteins assist the blood in clotting and forming a scab. While the lymphatic system is cleaning the remaining fluid to be filtered to go back into blood. The openness of the capillaries make it easier for phagocytes to escape. They will then come to the site to seize the pathogens and clean up dead cells. Since neutrophils were the first to arrive first they are starting to die out near the end. Interferons are then present and they alert and protect the surrounding cells that have not yet been infected. This then allows antiviral proteins to block viral reproduction. Therefore, when leukocytosis occurs after the virus starts to heal they are then alerted by the capillaries to come. The neutrophils then bind to the capillary walls near site of virus and squeeze through the vessel to start working. Then monocytes turn into macrophages replacing the neutrophils, cleaning up the rest of the