1. Briefly describe the process of inflammation in an area that has been traumatized.
As one of the second line of defenses under innate immunity, inflammation happens in response to tissue damage. This nonspecific defense occurs in order to clear out foreign materials at the injury site and prevent them from spreading to nearby tissues. Moreover, inflammation is necessary in preparation for tissue repair. A traumatized area undergoes inflammation in 3 steps. First is the vasodilation and increased blood vessel permeability. At this stage, more blood can flow, thus removing microbial toxins and dead cells, and the defensive proteins can now enter the affected area and the clotting sequence can begin. Secondly, the emigration of phagocytes happens within an hour after the prior stage. Neutrophils stick and squeeze through the blood vessels to go to the traumatized area and perform phagocytosis. As neutrophils die off rapidly, monocytes will now be in action and will be transformed into wandering macrophages. Together with the fixed macrophages on the tissue, these wandering macrophages increase the phagocytic activity. Afterwards, tissue repair will take place. Along this process, pus, a collection of dead phagocytes and damaged tissue, is formed and is gradually destroyed and absorbed.
2. Choose one type of Immunity (Innate and Humoral) and explain how its mechanism protects our body.
Innate immunity is the nonspecific defense that is already present at birth. This type of immunity doesn’t concern itself with specific recognition of a certain microbe, instead, it has a general and same way of defending the body against all microbes. Innate immunity has two primary components: the first and second line of defense.
The first line of defense involves the skin and mucous membranes which provides the external physical and chemical barriers which protect the body from pathogens and other foreign materials that may cause disease when they successfully penetrate the line of protection. The skin, being the primary protective layer of the body, sheds periodically which helps in removing microbes attached to the superficial layer of the epidermis. Meanwhile, the mucous membranes secrete mucus that traps microbes and other foreign materials. In addition, there are various types of fluids secreted by several organs that also aid in expelling pathogens and microbes out of the body.
The latter mechanism in innate immunity involves the second line of defense which works on the internal immune responses when pathogens are able to pass the aforementioned first line of defense. This component includes several immunological features including internal antimicrobial substances, natural killer cells and phagocytes, inflammation (which processes were mentioned above), and fever. These antimicrobial substances inhibit microbial growth which can be done by interferons, complement, iron-binding proteins, and antimicrobial proteins. Natural killer cells and phagocytes, on the other hand, have a primary focus on phagocytosis as it occurs through the stages of chemotaxis, adherence, ingestion, digestion, and finally, killing. Lastly, fever, which is described as having a very high body temperature, can elevate the effects of interferons, limit some microbial growth, and quicken body repair.
Reference:
Tortora, G. & Derrickson, B. (2017). Chapter 22: The Lymphatic System and Immunity. Principles of Anatomy and Physiology (15th ed.). Wiley.