ACTIVITY 1
Answer the following questions:
1. Briefly describe the process of inflammation in an area that has been traumatized.
Inflammation is one of the body's nonspecific defensive responses to tissue damage through the disposal of microbes, toxins, or any foreign material at the injury site, preventing them from damaging other tissues. The inflammatory response occurs in three stages: (a) vasodilation and increased permeability of blood vessels, (b) emigration (movement) of phagocytes from the blood into interstitial fluid, and (c) tissue repair.
(a) Vasodilation and Increased Blood Vessel Permeability: In the area that has been traumatized, vasodilation of arterioles will occur, promoting blood flow through the damaged area and removing microbial toxins and dead cells. Permeability of blood vessels will also increase, allowing the defensive proteins, or the antibodies and clotting factors, to reach the area of injury from the blood.
(b) Emigration of Phagocytes: Emigration process refers to the neutrophils sticking to the inner surface of the endothelium of blood vessels, then squeezing through the blood vessel wall to reach the area that has been traumatized. These neutrophils attempt to eliminate invading microbes via phagocytosis. Monocytes follow the neutrophils into the area of infection then transform into wandering macrophages, which are more potent phagocytes compared to neutrophils. When these macrophages die, pus formation occurs eventually and proceeds until the infection subsides. Pus either reaches the body surface, drains into an internal cavity and dispersed, remains even after the termination of infection, or is gradually destroyed and absorbed.
(c) Tissue Repair: The last stage of the inflammation process is the restoration or repair of tissues, a complex biological reaction involving immune and connective tissue cells interactions.
2. Choose one type of Immunity (Innate and Humoral) and explain how its mechanism protects our body.
Innate (nonspecific) immunity, or the defenses present at birth, includes the external physical and chemical barriers and internal defenses. The first line of defense is the external physical and chemical barriers provided by the skin and mucous membranes. These barriers prevent the body from acquiring diseases due to pathogens and foreign substances through (1) periodic shedding of epidermal cells to remove microbes at the surface of the skin, (2) secretion of mucus to trap and filter microbes, dust, and pollutants from inhaled air, (3) production of fluids, such as tears and saliva, and (4) secretion and production of substances and chemicals, like sebum and gastric juice, to flush microbes and destroy bacteria. When pathogens are able to penetrate the first line of defense, they encounter the second line of defense or the internal defenses like the antimicrobial substances, natural killer cells, phagocytes, inflammation, and fever. These defenses (1) discourage microbial growth (antimicrobial substances), (2) attack body cells that exhibit abnormal plasma membrane proteins (natural killer cells) through cytolysis, or cell bursting, and apoptosis, or self-destruction, (3) ingest microbes, cellular debris, and other particles (phagocytosis), (4) dispose microbes and other foreign material (inflammation), and (5) intensify the effects of interferons, inhibit growth of microbes, and speed up repair through body reactions (fever).
REFERENCES:
Soliman, A. M., & Barreda, D. R. (2022). Acute inflammation in tissue healing. International Journal of Molecular Sciences, 24(1), 641. https://doi.org/10.3390/ijms24010641