Major Questions in Immunology - Coursework Example

Innate immunity is one of them and it is the first line of defence when a pathogen gains entrance into the body the system works by hindering the pathogen. Innate immunity is usually the immediate and non-specific response. The Adaptive immune response is only activated when the pathogen evades the innate immunity. Adaptive immune response acts by recognising of the pathogen and is retained after the pathogenic infection has been eliminated (Doan, 2008).

The Humoral immune response is a branch of an adaptive immune response. Humoral immune response act on pathogens that are outside the bed such as toxins and bacterias, during the response antibodies which are protein bodies present in the body are produced and secreted into the bloodstream and other body fluids to help in fighting with the intruding agents by binding to them and destroying them (Doan, 2008).

 In the case of the student who was first exposed to the avian flu, the humoral system retained the response given first hence when the student was infected again by the flu the immune response had the memory and hence acted on it faster than the first time (Doan, 2008).

Components of the adaptive immune response:
- Only found in vertebrates.
- Has an antigen-specific and pathogen response.
- Has an extended time between exposure and maximal response.
- Has immunologic response due to prior exposure.

The T helper cells are responsible for suppressing and regulating innate responses. Low helper T-cells result in hypersensitivity reactions in the patient because the body will view the host’s antigen-presenting antibody as foreign and go on to destroy all the host antigens. Low helper T-cells lead to fewer killer cells in the body and this leads to lower antibody class switching (Doan, 2008).

Activation-induced deaminase: Helps in a mutation of the somatic cells and helps generate antibodies with a higher affinity to antigens. Important in the recombination of the class switch of B cells from IgM to IgG.

C5 (complement): It is divided into C5a and C5b. Complement 5b forms a membrane attack complex while complement 5a plays a role in chemotaxis.

FcRn receptor in neonates: It functions to transport IgG from the mother to the fetus. How pathogens can demonstrate to the immune system that they are foreign. The pathogens have antigens on them that the body interprets as a foreign body and acts to neutralize it (Doan, 2008). How innate immunity recognizes pathogens.

Surface barriers: They include chemical, mechanical, and biological barriers. Chemically the skin produces an antimicrobial agent that protects against pathogens. Mechanically, sneezing helps to expel foreign bodies present in the respiratory tract.

Inflammation: This response comes first after an infection. Cytokines are produced and they communicate with the white blood cells to recruit immune cells to the infection site hence healing takes place after the removal of the pathogens (Doan, 2008).