Body Defence

• The second line of defence fights pathogens through phagocytosis, where white blood cells engulf and digest the pathogens.
• Pathogens enter the body through the respiratory system, digestive system, excretory system, and skin.
• The first line of defence prevents pathogens from entering the body through the skin and mucous membranes.
• The body defence system can be divided into two categories:

  1. Non-specific body defence mechanism which are first and second-line defence.
  2. Specific body defence mechanism which is third line defence.
• The third line defence is where antibodies attack the pathogen by attaching to the pathogen and preventing it from entering the host cell. This will cause the pathogens to clump together and slowly destroy it.
• Third line defence is body immune system
• An antigen is a foreign substance that comes from outside the body and induces the production of antibodies
• Immunity: the state or quality of being resistant to a particular infectious disease or pathogen before being infected
• Vaccine injection is important to increase the antibody level in blood. The level should be higher than immunity level. This is important to provide an effective immunity.
• if the level of the antibody is low, the body cannot resist the pathogens
• Passive immunity can be obtained naturally through breast milk or from the mother's blood, or artificially through the injection of antiserum.
• Immunisation is an effort to stimulate the body's defense against infections by injecting vaccines containing antigens obtained from a weakened or dead virus or bacterium.
• Active artificial immunity is achieved through vaccination, while passive artificial immunity is obtained by injecting antiserum into the patient's body.
• Active immunity is obtained when the body produces an antibody when stimulated by antigen

  It is long lasting and offers better protection
• Passive immunity is obtained when the body received antibodies from other sources it is temporary and offers inferior protection.
• Vitamin C will boost the production of white blood cells. Therefore, it will increase the production of antibodies. This is important in order to fight infections.
• Smoking will interrupt our blood circulation. Thus it will interrupt the circulation of immune system substances in the body resulting in weakening of our immune system causing us high risk of getting infections.
• Immunisation saves lives. It helps protect future generations by putting an end to diseases. Many infectious diseases are rare now as a result of immunisation programs.
• Factors of low immunity:

  • High risk patient
  • Concentration of antibody is lower than immunity level


  How to boost immunity:

  • Take booster shot
• Prevent spread of infectious disease:

  • Self quarantine
  • Sanitise to avoid contamination
  • Go to hospital to get treated
• Importance of immunity:

  • Herd immunity
  • To protect those who are sickly/low immunity
  • To prevent the person from falling sick badly