Activity 1:
- Briefly describe the process of inflammation in an area that has been traumatized.
Whenever our body is damaged, as is the case when you scrape your knee or get a cut, you can usually notice that the area around this wound becomes red, and it swells. Whenever you experience these symptoms of inflammation (redness, swelling, heat, pain and in some cases loss of function) you can expect that your body is working overtime to dispose of microbes, dead tissue, toxins and other foreign objects in this site of injury, because if not the wound may further escalate to an infection, so our body’s main objective is to quickly stop this from happening. The 3 stages of the process are as follows: the Vasodilation and Blood Vessel Permeability that allows more blood to flow in the site which in turn also flushes toxins and dead cells, permeability permits defense mechanisms like antibodies and clotting factors into the area which is key in stopping these pathogens. The next stage is the Emigration of Phagocytes where first neutrophils and then followed by monocytes come to the site to destroy microbes via phagocytosis, these phagocytes die in a few days however and this leads to pus formation. The last stage of inflammation is where our tissue repairs itself.
- Choose one type of Immunity (Innate and Humoral) and explain how its mechanism protects our body
Humoral Immunity or antibody mediated-immunity is mainly facilitated by Plasma cells which are the effector cells of B cells, the main process in which these cells protect our body is through antibodies that circulate all around our body. The first part of this defense mechanism is B-cell activation and cloning, where antigens bind to the B-cell receptors meanwhile Helper T-cells also recognize these antigens functioning as costimulators for activation, Once activated these cells undergo clonal selection and produces plasma cells that secrete antibodies and memory B cells that can differentiate into more plasma cells. Antibodies or Immunoglobulins, are the key substance that facilitates humoral immunity, these antibodies have the following functions in disabling antigens:
- Neutralizing antigens – neutralizes toxins and prevents attachment of viruses
- Immobilizing Bacteria - antibodies form against antigens on cilia and flagella, losing motility
- Agglutinating and Precipitating antigen - antigen-antibody reactions may crosslink pathogens and clump together, phagocytic cells ingest these agglutinated microbes;
- Activating complement – where complexes initiate pathways of the complement system
- Enhancing phagocytosis by attracting phagocytes with antibody stems
Some classes of Immunoglobulins include: IgG (protecting us from bacteria and viruses; can be passed down from mother to fetus) IgA (provides localized protection of mucous membranes) IgM (Indicates recent invasion, after initial exposure) IgD (B-cell activation) and IgE (Allergic reactions and parasitic worms). Our immune system also has Immunological memory, where our body remembers specific antigens and as a result of this secondary responses have a higher affinity for the antigen disposing of it more successfully relative to primary responses.