1. Briefly describe the process of inflammation in an area that has been traumatized.
Inflammation is a nonspecific, defensive response of the body to tissue damage, produced by pathogens, chemical irritations, distortion of cells, and/or extreme temperature. It is a vital defense to continuously maintain homeostasis when we have damaged tissues.
- Vasodilation and Increased Blood Vessel Permeability. Blood vessels present in the site of the wound immediately respond by vasodilation of arterioles and increase in permeability of capillaries. Vasodilation allows an increase in the blood flow in the damaged tissue, helps in repairing the damage and in removal of microbes. On the other hand, as capillaries become more permeable, defense cells easily penetrate the site of injury— eliminating toxins and initiating repair as well.
- Emigration of Phagocytes from the Blood into Interstitial Fluid. Within the first hour of the inflammatory process, neutrophils stick to the endothelium of blood vessels, then squeeze through the walls to reach the damaged area. Once they reach the location of the wound, neutrophils phagocytize microbes, toxins, and dead cells— the defense mechanism of the body. They are also aided by wandering macrophages which also engulf invading substances. After a few days, the dead cells and fluids form a pus.
- Tissue Repair. Injured tissue gradually heals to resume its normal function. The process involves: development of new blood vessels in the injured area, fibroblasts attaching a temporary extracellular matrix, re-epithelialization, and contraction of myo-fibroblasts, reducing the size of the injured tissue. When the wound closes, the inflammatory cells vanish and the injured tissue returns to its original state.
2. Choose one type of Immunity (Innate and Humoral) and explain how its mechanism protects our body.
Innate Immunity is the defense system with which we were born. It protects the body against all antigens. The two lines of defense that make up innate immunity are the mechanical barriers that coat the body's exterior and the cells and chemicals that operate as the body's first line of defense against invasive infections. Surface membrane barriers, in particular the mucous membranes and the epidermis, are the first line of defense since they both keep infections out of the body. The epidermis is made up of keratin, which offers resistance to acids, alkalis, and bacterial enzymes, and an acid mantle that makes the epidermal surface acidic and prevents bacterial development. Conversely, the mucous membranes are made up of lacrimal secretion, stomach juice, nasal hairs, cilia, and the vaginal acid mantle.
Antimicrobial chemicals, phagocytes, natural killer cells, and inflammatory responses are examples of the cellular and chemical defenses that make up the second line of defense. The elements of the second line of defense will eliminate the infections generally rather than focusing on specific pathogens, if they are strong enough to get past the first line of defense. Phagocytosis, fever, and inflammatory reactions are a few examples of this.