1. It is known that inflammation is a nonspecific, defensive response of the body to tissue damage. This defense mechanism is an attempt to dispose of microbes, toxins, or foreign material at the site of the injury, to prevent their spread of other tissues, and to prepare the site for tissue repair in an attempt to restore tissue homeostasis. In simpler terms, inflammation occurs when disturbance of cells, pathogens or abrasions are present as it acts as a defense response to further initiate the healing process.
There are also signs-symptoms that are associated with inflammation; pain, redness, immobility, swelling, and heat.
Notably, the process of inflammation has three basic stages:
Vasodilation and Increased Blood Permeability: Vasodilation (widened blood vessel; increase in diameter) indicates the increase in blood that will flow to the area that has been traumatized, which is also apparent as redness and heat can be seen. In this accord, the occurrence of vasodilation also allows the removal of dead cells and microbial toxins. Increased blood permeability allows defensive proteins and clotting factors that are normally confined in the blood, pass through and enter the traumatized area.
Phagocyte Emigration: As neutrophils start to adhere or stick to the endothelium of the blood vessel moving and squeezing towards the affected area, phagocyte emigration occurs. They then will eliminate the invading microbes by the process of phagocytosis (engulfing) ultimately battling out further infection. Also, neutrophils worn-out, macrophages are the ones who engulf damaged tissue and invading microbes. Lastly, pus formation occurs.
Tissue Repair: Regeneration tissue happens as an indication of healing in the affected area.
2. Innate immunity comprises the external physical and chemical barriers provided by the skin and mucous membrane. Notably, the skin and mucous membranes are the first line of defense against pathogens. Aside from these, antimicrobial substances, natural killer cells, phagocytes, inflammation, and fever are present as internal defenses. Innate immunity is also indicated to be “nonspecific” as it takes action in the same manner towards all pathogens, microbial toxins, germs, etc.
With its mechanism of action, innate immunity protects the body by the skin providing a physical barrier against foreign pathogens, preventing their entrance, penetration, and potential infection to the body. First, sebum overall protects the surface of the skin. Second, mucus acts as a lubrication for cavity surfaces hence it also has the ability to trap microbes due to its viscosity. Moreover, mucus-coated hairs traps and filters out the inhaled air during respiration. Gastric juice that contains acid and enzymes can destroy bacterial toxins due to its high acidity. Lastly, in terms of apparent elimination of microbes, sweat, vaginal discharge, urine, and defecation then occurs.
References
Institute for Quality and Efficiency in Health Care. (2020, July 30). The innate and adaptive immune systems - InformedHealth.org. NCBI. https://www.ncbi.nlm.nih.gov/books/NBK279396/
Tortora, G. J., & Derrickson, B. (2017). Principles of Anatomy and Physiology (15th ed.). John Wiley & Sons, Inc