(a)+HDS+overview

**(a) First line of defense** Skin makes it impossible for microorganisms to penetrate Mucus dmembranes = Traps micro-organisms and prevents further entry **(b) Second line of defense** Phagocytes recognize foreign pathogens by the antigen on its surface. They engulf the pathogen via phagocytosis. They secrete enzymes and destroy the pathogen. Phagocytes are flexible and can push through pores in capillaries into tissues. **(c) Third line of defense** In this line, the production of antibodies is involved. They produce different kinds of lymphocytes which are specific to particular antigens. Clone is a group of lymphocytes, all producing same antibody which will attach itself to the antigen >>> make it harmless. **(2) Distinguish between the following categories of resistance to pathogens (KIM)** **(a) Non-specific resistance (= first line of defense)** This system responses automatically to any and all foreign substances including pathogen. Non-specific resistance system is skin and mucus. >>> wipe out all pathogens and decrease workload for other lines of defense **(b) Specific resistance (= immune system = third line of defense)** This system produces different kinds of lymphocytes which are specific to particular antigens and make them harmless. This is when your immune system is weak and it is easier for bacteria or viruses to attack your body. b. ** Resistance ** : the natural ability of an organism to resist microorganisms or toxins which produce diseases. This helps strengthens the body's immune system as it will be less likely that the body can get ill from the microorganisms. c. ** Phagocytosis ** : when white blood cells "eat" up the cells that are not recognised to be from the body, in other words, foreign cells. This process helps get rid of bacteria and other microorganisms that are harmful for the body. d. ** Inflammation ** : a localized physical condition in which part of the body becomes reddened, swollen, hot, and often painful, esp. as a reaction to injury or infection. The inflammatory response occurs when tissues are injured by bacteria, trauma, toxin, heat or any other cause. The damaged cells release chemicals which cause blood vessels to leak fluid into the tissue which causing swelling. This is to isolate the foreign substance from further contact with body tissues.
 * (1) Describe the __type of responses__ against pathogens carried out by each of the following levels of defense (KIM)**
 * Lungs protected by mucus and cilia which transports mucus to throat(dust is captured by mucus, cilia moves the mucus up and we swallow it into our stomach
 * Glands above eyes produce tears that contain lysozymes. The enzyme destroys bacterial cell walls
 * Vagina produces mucus and has an acidic environment
 * (3) Briefly define the following terms and give a short explanation of their role in internal defense (Anna) **
 * a. Susceptibility ** : the state of being likely to be harmed or influenced by a particular thing.

It is an important part of the body's defense against infection. Al though a fever signals that there is a battle going on within the body, but it is //for// the body and not against it.
 * e. Fever ** : the increase in the body's temperature in response to some disease or illness.