Module 08 Homework Assignment
1. Discuss the four (4) different classifications of emerging and re-emerging infectious diseases and give examples of diseases for each class. How do these classes differ from the three groups classified by the National Institute of Allergy and Infectious diseases (NIAID)?
There are four major groups of emerging and reemerging diseases which are classified as newly emerging, reemerging, new manifestations, and known agents in new geographical territories. Newly emerging disease are Hantavirus, Ebola, and aids which are seen as new in human population with respect to human history. Reemerging disease such as malaria and tuberculosis are ever present in ...view middle of the document...
2. Describe at least three (3) factors that play a role in the emergence of infectious diseases:
Emergence or reemergence of infectious diseases are influenced by: (1) human demographics and behavior which cause changes in population concentration such as migration or war evacuation, urbanization, economic conditions affecting living conditions, and the increase age of the general population. (2) Ecological changes and agricultural changes due to changes in farming practice, economic development, and changes in land use. (3) International travel exposes outsiders to exotic disease which can be carried home by the outside individual as well as pathogens of foreign disease being transported on imported goods from other parts of the world.
3. Describe the three (3) different lines of immune host defenses in the human body and give specific examples of each line. Which line(s) provide general immune protection and which provides specific immune protection?
The first line of defense are the physical barriers to pathogens which are provided by the skin, mucous membranes, tears, and saliva.
The human body’s second line of defense consists of internal processes to either control the spread or destroy pathogens through the following: inflammation which increases transport of immunity cells to the site of pathogen exposure; generation of a fever in order to raise the body temperature higher than what many pathogens can survive at or at least cannot reproduce at; release of phagocyte cells which destroy pathogens by ingesting and digesting pathogen cells; Alpha, Beta, and Gamma glycoproteins or interferons provide antiviral protection by interfering with the reproduction of viral pathogens to prevent the spread of the virus; and activation of the complement system that consists of more than 35 soluble proteins found in extracellular fluid which are activated by immune system in response to invasive pathogens. The complement system influences both innate and acquired immunity and is so named because it complements the cascade of the second line of defense.
The third line of defense consists of specific or adaptive defenses that can be triggered by specific antigens or be a response of cell-mediated and humoral immunity. The cell-mediated immunity is provided by actions controlled by T-Cells which react in a specific way based on their cell type. Cytotoxic T-Cells recognized an antigen and then destroy any antigen-bearing cells. Helper T cells aid in the immune response by stimulating growth and division of the cytotoxic T cells and B lymphocytes. Suppressor T cells regulate the immune response by releasing chemicals which suppress helper T cells and the antibody production of B cells. Memory T cells remain after suppression of the immune response in order to recognize the antigen in the future.
4. Differentiate between active and passive types of immunity. Which type of immunity is long lasting and which is short...