N3 Anatomy and Physiology AY 2023-2024

Activity 1: Inflammation and Immunity

• Briefly describe the process of inflammation in an area that has been traumatized.
  • An inflammation is a reaction brought on by harm to living tissues. Higher organisms have evolved an inflammatory response as a defense mechanism to keep them safe from harm and infection. Its goal is to remove damaged tissue components and localize and eradicate the harmful agent so that the body can start healing. The inflammatory response has multiple stages:
    • First stage: Vasodilation (Blood Vessels Dilate) and Increased Blood Vessel Permeability

      • The acute vascular inflammatory response is the first step in the healing of acute injuries. Vascular alterations are intended to improve local blood flow as well as mobilize and deliver cells to the location to start the healing process. The body starts to rebuild collagen in the injured area after removing the damaged cells. This stage lasts three to five days and starts as soon as the damage occurs.

      • The blood vessel walls then become more permeable, allowing only water and salts to pass through with ease. Exudate, a fluid rich in proteins, can now escape into the tissues. Clotting factors, which aid in halting the transmission of infectious organisms throughout the body, are among the substances found in the exudate. Antibodies are among the other proteins that aid in eliminating invasive microbes.

    • Second Stage: Emigration of phagocytes

      • The term "emigration process" describes how neutrophils adhere to the inner surface of blood vessel endothelium and subsequently squeeze through the wall of the blood vessel to reach the injured area. These neutrophils use phagocytosis to try and get rid of invasive microorganisms. Once inside the infected area, monocytes accompany neutrophils and change into more effective phagocytes called wandering macrophages. Pus eventually forms once these macrophages die, and it continues until the infection goes away. Pus either spreads throughout the body after reaching the surface, drains into an interior cavity and stays there even after the infection has ended, or is progressively absorbed and destroyed.

    • Third Stage: Tissue Repair

      • Endothelial cells create new blood vessels throughout the healing process, and fibroblast cells proliferate to create a loose connective tissue framework. Granulation tissue is the name for this thin, vascularized connective tissue. The little red granular patches that appear in healing tissue—such as the skin behind a scab—are the source of the name of this condition. New blood vessels form to provide blood circulation in the healing area as the repair process advances, while fibroblasts generate collagen to give the developing tissue mechanical strength.

• Choose one type of Immunity (Innate and Humoral) and explain how its mechanism protects our body.
  • Humoral immunity is based on the synthesis of antibody molecules in response to an antigen through a process that needs substances present in bodily fluids like humor. Antibodies produced by plasma cells serve as a link between the humoral and cellular immune responses. Helper T cells are activated and B cells become alerted when antigens bind to their antigen receptors. Helper T cell signals and antigen binding promote B cell development and differentiation into plasma cells that secrete specific antibodies. These antibodies can kill infections by adhering to them and obstructing their harmful effects. Additionally, pathogens can be coated, which enables opsonization by accessory cells to ingest and eliminate them. Additionally, antibodies have the power to trigger the complement system, which can greatly increase opsonization and even kill some bacteria directly.

References:

Inflammation | Definition, Symptoms, Treatment, & Facts. (2023, November 17). Encyclopedia Britannica. https://www.britannica.com/science/inflammation/Cellular-changes

Janeway, C. A., Jr. (2001). The humoral immune response. Immunobiology - NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK10752/

Tortora, G., & Derrickson, B. (2017). Principles of Anatomy & Physiology (15th ed.). Wiley & Sons.