LESSON 2.3

• NONSPECIFIC IMMUNE SYSTEM

  At birth, we were born with a number of defense mechanism to fight off disease-causing invaders or pathogens. They said to be nonspecific because defense is not aimed at specific pathogen. 
• IMMUNITY

  Immunity

  • defense response in the human body which fight the disease- causing organisms.
• NONSPECIFIC IMMUNE SYSTEM: FIRST LINE OF DEFENSE

  • it consist of a surface barrier and internal structures that employ physical and biochemical strategies to get rid of many microorganisms before they can invade body tissues. 
• WHAT ARE THE BARRIERS THAT HELP PREVENT PATHOGENS FROM ENTERING THE BODY

  Physical Barrier & Chemical Barrier
• PHYSICAL BARRIER


  protective walls that prevent  invasions. 
• CHEMICAL BARRIER

  • enzymes are produced in tears, saliva and perspiration. That can disrupt the cell walls of the microbes.
• MUCUS 


  chemical defense that is secreted and acts as protective barrier that blocks the bacteria from sticking to the inner epithelial cells.
• CILIA


  with its tiny hairs in the respiratory system that sweat up mucus.
• STOMACH ACID 


  kills germs that enter the alimentary canal.
• NONSPECIFIC IMMUNE SYSTEM: SECOND LINE OF DEFENSE


  It is also known as the other circulatory system, the lymphatic system, aside from collecting and recycling fluids that leaked from the circulatory system, it also plays a major role in fighting bacterial and viral infections.
• LYMPHATIC SYSTEM

  it consist of a network of lymphatic vessels and organs, nodes and tiny bean structures called lymph nodes
• LYMPH TISSUES


  are located in various parts of the body, which include tonsils, thymus, spleen, and bone marrow. Once the leaked fluid passes by diffusion into the lymphatic vessels,
• LYMPHOCYTES

  fight off infections, it also produced in the spleen, the largest organ of the lymphatic system.
• SPECIFIC IMMUNE SYSTEM: THIRD LINE OF DEFENSE

  The adaptive (specific) immune system makes antibodies and uses them to specifically fight certain germs that the body has previously come into contact with.
• SPECIFIC IMMUNE SYSTEM: THIRD LINE OF DEFENSE


  This is also known as an “acquired” (learned) or specific immune response.
• SPECIFIC IMMUNE SYSTEM: THIRD LINE OF DEFENSE


  It response take days or even weeks to become established. However, it is more specific to an invading pathogen.
• SPECIFIC IMMUNE SYSTEM: THIRD LINE OF DEFENSE


  It is also activated when the innate immune response is dependent on the information from the innate immune system, that is without it, the adaptive response could not be mobilized.
• WHAT ARE THE TWO ADAPTIVE RESPONSE

  Cell-Mediated & Humoral
• CELL-MEDIATED


  occurs cytotoxic cells defend the body against infection.
• CELL-MEDIATED

  The development of B and T cells, memory cells and plasma cells are important aspects of cell-mediated immune mechanism.
• HUMORAL

  The humoral response is due to the production of antibodies by B-cells.
• T CELLS

  are white blood cells that are produced in the bone marrow and mature in the thymus. 

  are activated when they encounter antigens in the lymph nodes. 
• WHAT ARE THE 3 MAJOR TYPES OF T CELLS

  Cytotoxic T Cells, Helper T Cells, and Regulatory T Cells
• CYTOTOXIC T CELLS

  Cytotoxic T cells recognize virus-infected cells and kill them.
• HELPER T CELLS


  cells secrete proteins that help other immune cells (B cells, macrophages, etc.) survive and perform their function.
• REGULATORY T CELLS


   Control the immune response by turning it off. This prevents the immune system from harming the body.
• B CELLS


  are white blood cells that develop and mature in the bone marrow. are activated when they encounter antigen in the lymph nodes.
• ANTIBODIES

  produce a highly potent protein, that is specific to neutralize the antigens by making them more susceptible to phagocytosis.
• WHAT ARE THE TWO PHASES FOR THE BODY TO PRODUCE ANTIBODIES

  Activation Phase & Effector Phase
• ANTIGEN PRESENTING CELL (APC)


  eats the  invading virus creating processed antigens.
• HELPER T CELLS 


  recognize the presented antigens binding itself with the antigen.
• WHAT ARE THE 3 MECHANISMS BY WHICH ANTIBODIES INHIBIT INFECTION

  Neutralization, Opsonization, and Complement Activation
• NEUTRALIZATION 


  Antibodies prevent a virus or toxic protein from binding their target.
• OPSONIZATION


  a pathogen tagged by antibodies is consumed by a macrophage or neutrophil
• COMPLEMENT ACTIVATION


   antibodies attached to the surface of a pathogen cell activate the complement system destroying the pathogen.
• WHAT ARE THE 5 GENERAL TYPES OF ANTIBODIES IN HUMANS

  IgA (Immunoglobulin alpha), IgD (Immunoglobulin delta), IgE (Immunoglobulin epsilon), IgD (Immunoglobulin gamma), and Igm (Immunoglobulin mu)
• IgA (Immunoglobulin alpha)


  * Found in mucosal areas, such as the gut, respiratory tract and urogenital tract. It prevent colonization by pathogens.

  • It can also be found in saliva, tears and breast milk. 
• IgD (Immunoglobulin delta)

  • Function mainly as an antigen
  • Receptor on B-cells that have not been exposed to antigens It has been shown to activate basophils and mast cells to produce antimicrobial factors
• IgE (Immunoglobulin epsolin)

  • binds to allergens and triggers histamine release from mast cells and basophils and is involved in allergy.
  •  It also protects against parasitic worms.
• IgD (Immunoglobulin gamma)

  Provides s the majority of ansib antibody-based immunity against invading pathogens. The only antibody capable of