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IBDP Biology- The Immune System

Topic 11.1- Different ways the body protects itself

July 12, 2021

In this IBDP Biology Post, we will be looking at :

  • Histamines
  • Types of antibodies and pathogens during pregancy

Histamines 

Histamine: Small organic molecules produced by two types of leukocyte - basophils and mast cells

Key effect in the immune response: Increases permeability of capiliaries to white blood cells and other proteins such as antibodies

Function of Histomine: 

  • Dialation of small blood vessels in the infected area causing the vessels to become leaky
  • Increases the flow of the fluid containing immune components to the infected area
  • Allows some of the immune components to leave the blood vessels resulting in both specific and non-specific responses

This allows the components of the immune system to engage the pathogen early at the site of infection 

Cells have histamine receptors

Histamine trigger symptoms of allergy:

  • Nose itching, fluid build up, sneezing, inflammation
  • Allergic rashes
  • Anaphylaxis (dangerous swelling)

To lessen effets of allergic responses - Anti-Histamines can be taken 

Monoclonal Antibodies 

Monoclonal Antibodies are used for the treatment and diagnosis of diseases

Examples are:

  • Test for malaria to identify whether either humans or mosquitoes are infected with the malaria parasite
  • Test for the HIV pathogen

B cells are fused with Myeloma which produced many different hybridoma cells

Each Hybridoma cell is tested to find the cells that produces the required antibody

The desired Hybridoma cells is then allowed to divide and form a clone

The clones secrete the orginal antibody produced by the original Lymophocyte

  • An animal is injected with an antigen and in response produces specific plasma cells
  • The plasma cells are harvested from the spleen of the animal
  • Harvested plasma cells are fused with tumor cells forming hybridoma cells
  • Hybridoma cells are screed to see which ones are producing useful antibodies
  • The selected hybridoma are allowed to divide and produce clones 

Monoclonal Antibodies are used in pregnancy test kits

  • The urine of pregnant women contain hCG: protein secreted by the developing embryo and later by the placenta
  • Pregnancy test kits 

contain monoclonal antibodies to which hCG binds. This causes a coloured band to appear indicating that hCG is present in the urine sample and that the woman is pregnant 

That's all for this post!

References:

  • https://www.google.com/url?sa=i&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FHistamine&psig=AOvVaw2h3WAhbcnGK72nsy0bHpUd&ust=1626203391439000&source=images&cd=vfe&ved=0CAoQjRxqFwoTCPCjxe6d3vECFQAAAAAdAAAAABAD
  • https://www.google.com/url?sa=i&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FMonoclonal_antibody&psig=AOvVaw1w4-vkoRpfnL1xCh18Mjx5&ust=1626203445742000&source=images&cd=vfe&ved=0CAoQjRxqFwoTCLDK_Iie3vECFQAAAAAdAAAAABAD

Drafted by Venetia (Biology)