Process of Inflammation
Vasodilation and increased permeability of the blood vessels occur to allow more blood to flow to the traumatic site of injury which also paves way for antibodies and clotting factors to enter the injured area. Neutrophils then emigrate (travel to the injured area) while monocytes follow them to get rid of damaged tissues, worn-out neutrophils, and any microbes. This is the process of inflammation, which will then be followed by a proliferative process of tissue repair where new blood vessels are formed around the injury, fibroblasts lay down a temporary extracellular matrix which allows epidermis to be reconstructed, and where contracting the size of the wound by the myo-fibrils attracted to the injured area occurs. Once complete, remodeling of the tissue occurs to bring it back to its normal characteristics.
Innate Immunity
Simply put, our innate immunity has two defenses: the first line of defense: the skin and the mucus, and the second line of defenses: antimicrobial substances, phagocytes, natural killer cells, inflammation, and fever.
Pathogens must go through the first line of defense first. Skin provides a barrier to inhibit the entrance of microbes inside our body. The constant sloughing off of our skin cells remove such microbes. Mucus, on the other hand, simply traps the foreign substances to prevent them from further entering our body. Other fluids are present in our body which also aids in preventing microbes from entering our body. Certain physiological activities, such as coughing or sneezing, also prevents entrance of foreign substances.
When pathogens/microbes/foreign substances were successful in passing through the first line of defenses, our body’s second line of defenses will counteract them. These defenses will carry out their specific mechanisms.
Additional Resources
LibreTexts Medicine. (2023, January 17). 5.5A: Steps of Tissue Repair. Medicine LibreTexts. Retrieved November 21, 2023, from https://med.libretexts.org/Bookshelves/Anatomy_and_Physiology/Anatomy_and_Physiology_(Boundless)/5%3A_Integumentary_System/5.5%3A_Wound_Healing/5.5A%3A_Steps_of_Tissue_Repair