The Specific Defence System(Complete) Flashcards
What is an antigen?
A foreign particle capable of causing an antibody response.
Stimulates b lymphocytes to produce antibodies.
Give 2 examples of antigens.
Viral protein coat.
Bacterial cell wall.
What is an antibody?
A specific defence protein produced by b lymphocytes in response to specific antigens in which they bind.
Each antibody only attacks a specific antigen
What is the main role of an antibody?
To deactivate antigens.
What is the specific defence system?
It attacks specific pathogens by the production of antibodies by b lymphocytes and the action of white blood cells.
It provides a precise response to each different antigen.
What are the three main types of white blood cells?
Monocytes- macrophages in their active form.
B lymphocytes.
T lymphocytes.
Name two organs in the human body which are specific to the immune system.
The spleen.
Lymph nodes.
Give a description on monocytes.
Monocytes are large white blood cels produced in the red marrow of long bones like the femur.
Called macrophages when actively fighting infection.
They have a kidney shaped nucleus
They carry out phagocytic action.
Describe how macrophages fight infection.
They develop into active macrophages which engulf and digest the pathogen.
They display the antigen to the outer surface to stimulate the production of antibodies by b lymphocytes.
They have a great effect on the control of viruses.
Give a description on lymphocytes.
The specialised white blood cells of the specific defence system produced in the red marrow of long bones like the femur.
They are almost 25% of the white blood cells.
The cytoplasm is small and rounded.
The nucleus takes up most of the space.
How are B and T lymphocytes classified?
By how they mature.
Distinguish between be a B lymphocyte and a T lymphocyte.
B lymphocytes are produced and mature in the red marrow and then move to the lymphatic tissue.
T lymphocytes are produced in the red marrow and mature in the thymus gland before moving to the lymphatic system
What hormone causes B and T lymphocytes to mature?
Thymosin.
How do B lymphocytes fight pathogens/infections?
B lymphocytes detect an antigen and produces antibodies specific to that antigen.
The antibody attaches to the antigen forming an antigen antibody complex.
Some antigens are deactivated by agglutination, attracting phagocytes to engulf the pathogens.
Other antigens are deactivated by lysis causing the pathogen to burst.
After infection, memory B cells are formed and they provide long lasting immunity by producing antibodies at a larger and faster rate if the infection appears again.
Also by reacting even when a small amount of antigen is present.
Name the 4 types of T cells.
Helper T cells.
Killer T cells.
Suppressor T cells.
Memory T cells.
