1. Briefly describe the process of inflammation in an area that has been traumatized.
The process of inflammation in an area that has been traumatized has three basic stages: (1) vascular permeability/vasodilation and release of mediators; (2) emigration of phagocytes; and (3) tissue repair and regeneration.
During the first stage, vasodilation allows increased blood flow in the damaged area. Increased permeability permits the entry of defensive proteins, such as antibodies and clotting factors, into the damaged area. With this, fibrinogen is changed into fibrin threads that localize and trap the microbes to prevent their spread. Histamine, kinins, prostaglandins, and leukotrienes contribute to vasodilation and permeability. This stage produces signs and symptoms of inflammation, such as redness and swelling.
At the second stage, blood accumulation causes a movement of phagocytes from the blood to the interstitial fluid. First, neutrophils, which are present during the early stages of infection, kill pathogens by phagocytosis. They are followed by monocytes, which transform into wandering macrophages and contribute to phagocytic activity. Neutrophils and monocytes will then eventually die after a few days of reactions. These dead phagocytes and the damaged tissue form the pus until the infection subsides.
Lastly, tissue repair and regeneration is initiated and begins.
2. Choose one type of Immunity (Innate and Humoral) and explain how its mechanism protects our body.
Innate immunity pertains to the defenses present in our bodies at birth. includes the external physical and chemical barriers provided by the skin and mucous membranes. It functions against all microbes in the same way and does not require specific recognition.
When microbes try to enter our system, our innate immunity protects our body using various components and lines of defense. The first ones are the physical and chemical barriers of the skin and mucous membranes that serve as our first line of defense. The skin's many layers of keratinized cells give us a formidable physical barrier; shedding of epidermal cells then removes microbes from the surface of the skin. Meanwhile, the mucous membranes lining the body cavities produce slightly viscous mucus that traps microbes and foreign substances. These barriers discourage pathogens and foreign substances from entering our system and causing disease.
When microbes penetrate the body’s first line of defense, they are addressed by the second line of defense: antimicrobial substances, natural killer cells, phagocytes, inflammation, and fever. Antimicrobial substances include interferons, complement systems, iron-binding proteins, and antimicrobial proteins that protect uninfected host cells, promote phagocytosis, prevent bacterial growth, and perform antimicrobial activities, respectively. Natural killer cells release perforin and granzymes to kill infected cells. Phagocytes ingest the microbe or foreign substance. Inflammation confines the microbes and signals the start of tissue repair. Finally, fever accelerates the body's response to repair.