HL Bio - Unit #2.5: Defense Against Disease (Responses)

Immune System

Help protect the body from infectious diseases

Innate Immune System

• Responds to broad categories of pathogens by initiating common responses

• The body still hasn’t had time to adapt to the pathogen so it uses general defenses

Adaptive immune system

• Adapt to the pathogen and create antibodies that will attack the specific pathogens

• Using white bloods cells specifically  B-lymphocytes and T-lymphocytes

Immunity

• Ability for the body to eliminate diseases from the body

  • B-cells remain inactive in the body until they are needed again and then secrete the antibodies much quicker

Phagocytes

• A type of white blood cell that is apart of the innate immune system 

  • Responds to all foreign substances in the same way (eating them up)

• They squeeze out through the pores in the walls of capillaries and move to the site of infection

Lymphocytes

• Another type of white blood cell apart of the adaptive immune system

  • Identify the type of pathogen they’re facing and create antibodies

  • A lymphocyte can only create one specific antibody

• They need to distinguish between the body cells and foreign cells

Antibodies

proteins that help destroy pathogens

Antibiotics

Medicine that fight bacterial infection in people and animals

• Can only block the DNA replication process in bacteria

  • Useless against viruses

• Too much use of antibiotics lead to bacteria resistance 

  Bacteria can pass along antibiotic resistant genes to other bacteria

Antibody Production

1. Pathogens are engulfed by macrophages and display it’s antigens on its surface

2. Helper T-lymphocytes then bind to the antigens by their receptor protein

   • The t-cells then bind to B-lymphocytes

3. When the antigen binds to B-cells it stimulates the B-cells to divide into a group of identical clones

4. Older B-cells make Plasma Cells: which have larger RER and Golgi apparatus and allows for more antibody production

Human Immunodeficiency Virus (HIV)

• A virus that attacks the body’s immune system

  • Destroys the helper t-lymphocytes causing a very weak adaptive immune system

• Can be passed through….

  • Shared needles

  • Unprotected sex

  • Transfusion of infected blood

HIV +

HIV patients that can produce antibodies against it are referred to as HIV+ 

Acquired Immunodeficiency Syndrome (AIDS)

Caused by untreated HIV

• The progressive loss of the capacity to produce antibodies

When conditions caused by HIV are combined in a person they now have Acquired Immunodeficiency syndrome (AIDS)

Zoonoses

Diseases that can be transmitted from one organism to the other

Zoonotic Diseases

Pathogens that can infect multiple species

Vaccines and Immunization

• Preparations used to stimulate the body’s immune response against disease

  • Administered through injections (Containing a killed, weakend, or synthetically manufactured version of the virus)

• Helps start a primary immune response in the body and stores them in their memory cells