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Briefly describe the process of inflammation in an area that has been traumatized.
Inflammation is a complex and essential biological response that the body initiates in reaction to tissue damage, injury, or infection. It serves as a protective mechanism, aiming to eliminate harmful stimuli, clear damaged cells and tissues, and initiate the repair process. The four hallmark signs and symptoms of inflammation, irrespective of the triggering factor, are redness, pain, heat, and swelling. Additionally, it may lead to a loss of function in the affected area, depending on the nature, site, and extent of the injury.
The inflammatory response can be broken down into three fundamental stages. First, there is vasodilation and increased permeability of blood vessels in the affected area. This process involves the widening of blood vessels and enhanced permeability of their walls, allowing an influx of immune cells, proteins, and other substances from the bloodstream into the surrounding tissue. This increased blood flow contributes to the characteristic signs of inflammation, such as redness and swelling. The second stage involves the emigration of phagocytes, particularly white blood cells like neutrophils and macrophages, from the bloodstream to the site of injury. Chemical signals released by damaged cells guide these immune cells to the affected area, where they play a crucial role in engulfing and digesting foreign particles, such as bacteria or debris. Finally, the third stage focuses on tissue repair. Once the threat is neutralized, and debris is cleared, the body shifts its efforts towards rebuilding and regenerating the damaged tissue. Fibroblasts produce collagen fibers, gradually replacing the damaged tissue with new, functional tissue. Overall, inflammation is a dynamic and precisely regulated process that contributes to the body's ability to defend itself and recover from injury.
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Choose one type of Immunity (Innate and Humoral) and explain how its mechanism protects our body.
Innate immunity, the body's first line of defense, is an inherent and immediate protective mechanism against a diverse array of pathogens, including bacteria, viruses, and fungi. Present from birth, this nonspecific immunity serves as the initial response before the more specialized adaptive immune system becomes active.
The first line of defense comprises the physical barriers of the skin, whose outer layer, the epidermis, forms a formidable obstacle for pathogens, and mucous membranes that line entry points into the body. These membranes secrete mucus, trapping pathogens, while cilia facilitate their removal. Chemical barriers, such as sebum on the skin and antimicrobial substances in mucous membranes, contribute to the prevention of pathogen entry.
The second line of defense, known as internal defenses, involves various mechanisms to counter infections that breach the first line. Phagocytes, including neutrophils and macrophages, play a pivotal role by engulfing and digesting pathogens. Inflammation is a nonspecific immune response that occurs in response to tissue damage or infection, involving increased blood flow, redness, and warmth, facilitating the arrival of white blood cells to eliminate pathogens. Fever, a systemic response to infection, inhibits pathogen growth and enhances immune cell activity. The complement system, a group of circulating proteins, and interferons, signaling proteins produced by virus-infected cells, contribute to immune defense by promoting inflammation, attracting phagocytes, and inhibiting viral replication. Together, these components of innate immunity provide a swift and effective response to a wide range of threats, safeguarding the body from harmful invaders.
Reference/s:
Tortora, G. J., & Derrickson, B. H. (2017). Tortora’s Principles of Anatomy & Physiology. Wiley.
WHAT IS INNATE IMMUNITY? (2021). Center for Innate Immunity and Immune Disease. https://ciiid.washington.edu/content/what-innate-immunity
Alberts, B., & Johnson, A. (2020). Innate Immunity. National Library of Medicine. https://www.ncbi.nlm.nih.gov/books/NBK26846/