Immunology

Defence mechanisms

Non-specific immune response

They have several ways to prohibit entry of pathogens, such as the skin, Hydrochloric acid in the stomach and epithelia cells that are lines with mucus and hairs to catch and cover the pathogens that the boy can then dispose of. This also includes complement proteins that are blood proteins that contribute to the brake down and removal of pathogens, and phagocytosis.  

Phagocytosis is a process whereby the phagocyte is attracted to the pathogens by chemicoattractants it secretes. The phagocyte binds to the pathogen and engulfs it by wrapping it body around the pathogen. Once included the lysosomes in the phagocyte release there lytic enzyme which breaks down the pathogen. The remains are then absorbed into the body of the phagocyte. 

Specific immune response

Cell mediate response involves T lymphocytes which are matured in the thymus gland and only happens in cells that have been infected. This process starts similarly to phagocytosis. The pathogen is engulfed by the phagocyte and breaks it down. But instead of absorbing the remains, it presents the antigens on it cell surface membrane: giving this type of cell its mane of Antigen-presenting cell. The presented antigens attract a T cell that has a receptor that compliments the antigen perfectly. This then triggers the T cell to divide by mitosis. The products are T killer cells being produced, stimulates phagocyte activity and B cells being produced. B cells form Plasma cells and Memory B cells, which aid in the patrolling of the body to flag out any other pathogens. T killer cells kill the pathogens by punching holes in their cell surface membrane and letting the content flow out of the cell.

Humeral Response involves two responses, primary and secondary. It only happens in the body fluids such as the blood systems. The primary response involves the pathogen engulfing the pathogen and presenting its antigens on the phagocytes cell surface membrane. The T helper cells compliment this antigen exactly and stimulate the B cell’s to divide by mitosis. They form plasma cells, which produce antibodies to fight the pathogen, and Memory cells.

Memory cells are part of the secondary response. Once the first wave has been fought off then the memory B cells remember the antibody that was made. When next the immune system comes in contact with that antigen than the antibody can be produced quickly and we, the humans, won’t feel any of the symptoms.

As shown on this diagram there are four chains with a variable region and a constant region.  The variable region is the one that changes depending on the antigen that is had to compliment.

There are what looks like two binding sites on this antibody but you don’t need to know why and what they do just how it looks.

There are three different types o f antibodies: Opsonises, Agglutinins and Lysins.

 Opsonises bind to the antigens and create a marker so the phagocyte can destroy them. Agglutinins clump the pathogens together which prevents them from entering cells. Lysins bind to the pathogen and cause it’s cell wall to rupture, rendering it dead.

Monoclonal antibodies

 This is a process whereby a non-dividing plasma cell is taken form an animal’s spleen. Then a dividing myeloma cell is taken and cultured with the plasma cell. This creates a hybrid of both cells which is called a hybridoma cell. This is them cultured and put into the area of the cancer. The cell now produced antibodies with the same genetic make up as the cancerous cells.  So our bodies are killing its own mutated cells.

This is used to treat cancers and translate surgery where the tissue of the implanted organ is cultured with your own cells so that the organ is accepted.

Immunity

 There are two types of immunity passive and active. Passive immunity is produced form an outside source such as vaccination, whereas active immunity is our own lymphocytes fighting off pathogens.

 You also need to know about herd immunity, which is when a high percentage of the people around you are vaccinated and you aren’t so you are protected from the outbreak because the people around you won’t catch it.

You may need to know about natural and artifical active immunity but these are just extras that will help they arent on the spec, I think.