1. There are multiple factors of Host-Pathogen interactions. In human pathogens must cross our first line of defense, the skin. Pathogens can gain entrance to the human body and other hosts through several avenues, which are called portals of entry. There are multiple ways that pathogens can penetrate host defenses. Pathogenic bacteria have many components that helps them make it across our first line and second line of defenses. Recall old information the capsule of bacteria can help them become a virulence factor. Bacteria capsule can resist phagocytosis; however, human can produce antibodies against the capsule, so the bacteria can be destroy by phagocytosis. The cell walls of these pathogenic bacteria are another factor that contribute to virulence factors. Theses cell walls contain chemical substance that contain that help them to resist the fight of white blood cells. In addition, once these pathogenic bacteria enter the host they can produce extracellular enzymes. Some examples are hyaluronidase, collagenase, and IgA proteases. Some pathogen can alter the surface antigen, so that the immune system antibodies won’t affect them. These pathogenic bacteria can produce protein called invasins which rearrange the actin filaments of the cytoskeleton. Rearranging actin filaments allow bacteria to be taking into the host cell.
2. Normal flora maintain permanent residence but do not cause disease unless something alter the balance and then the microbes have the chance to become an opportunistic pathogen. Pathogen are microorganisms that have the ability to cause diseases.
3. Norma flora harbor within the skin, GI tract, respiratory tract, urinary tract, and reproductive (vaginal) tract, and eyes.
4. Pathogenesis is the process of producing a disease; moreover, the term can also be define as the origin and development of the disease. The major steps involved in the progress of an infection are determine by organism factors, virulence, host factors, host innate and adaptive defenses, and the dose (number of organisms).
6. What is epidemiology is the science that study where and when diseases come from, how they occur, and how they transmitted in a population. 7. Norma flora benefits us by preventing the over growth of harmful bacteria. The normal flora protect the host by competing for nutrients; in addition, producing substances that are harmful to the evading microorganisms, and affecting condition such as pH and oxygen this is known as microbial antagonism. Immunity is the host defense mechanism. It’s is the ability to fight off infections by producing antibodies or cells to destroy foreign objects.
8. These defenses are always present, they aren’t specific like other components of our immune system. In addition, the innate immune system doesn’t have rapid memory response like adaptive immunity. The components of the innate immunity are the first line of defense, second line of dense, and the Toll like Receptors or pathogens molecules patterns. Transmembrane proteins of immune cell that recognize pathogens and active an immune response directed against those pathogen is known as TLRs.
9. Adaptive immunity is a response from the body when expose to the particular pathogen. Adaptive immunity is very specific to microbes. It’s actually called adaptive immunity because it adapt to handle a specific microbe. Adaptive immunity components of the immune system are the white blood cell such as the T lymphocytes and B lymphocytes. Adaptive immunity don’t just response to infection it also response to any foreign object that enter the body which called an antigen.
10. Phagocytosis
11. Self and non self refers to our immune system
12. and 13 Every year we need to receive the flu vaccination because the influenza virus can change its DNA strain and present different antigens that our immune system can’t recognize. This
