5.3- Cell Mediated immunity Flashcards
What is an antigen?
Any part of an organism or substance that is recognised as non-self by the immune system and stimulate a response.
Do specific immune responses create short or long term immunity?
Long- term
Where are lymphocytes produced?
By stem cells in the bone marrow
What are the two types of lymphocytes?
B-Lymphocytes (Hurmoral) and T- Lymphocytes (Cell-mediated)
What type of foreign material does T-Lymphocytes respond too?
Self-cells that have been affected (Virus) or cells from other individuals (Not genetically the same).
How do the T-lymphocytes know that a phagocyte has engulfed a pathogen?
The phagocyte will display some of the pathogens foreign material on the cell surface membrane.
How do the T-lymphocytes know that a virus has invaded a self-cell?
They present viral antigens on the cell-surface membrane.
How do T-lymphocytes know that transplanted or cancer cells are present?
They both have antigens presented on the outer cell-surface membrane.
What is the cell-mediated immunity?
Where T-lymphocytes respond to antigens that are presented on a body cell- Not in the bloodstream or bodily fluid.
What are the 4 things that, after mitosis, the T helper cell can do?
1) Develop into memory cells which allow a rapid response to future infections.
2) Stimulate phagocytosis to engulf pathogens.
3) Stimulate B cells to divide and secrete antibodies.
4) Activate Cytotoxic T cells.
What is the first step in the cell- mediated response?
The phagocyte has engulfed the pathogen and is now presenting antigens on its cell surface membrane.
What happens after the phagocyte presents the foreign antigens? Step 2 in CMR
The T helper cells have receptors that are complementary to the antigens being presented, then one of the four responses is produced.
How do cytotoxic T cells help to destroy pathogens? CMR
They produce a protein called perforin that creates pores within the cell-surface membrane, allowing substances to enter the cell and the cell dies.
What do B cells do?
They produce antibodies that are complementary to the pathogens cell-surface material.
What happens after the B cell binds with the foreign antigen presented on the cell-surface membrane? HR
The antigen enters the B cell by endocytosis and then gets processed and presented on its cell surface membrane.
What happens after the antigen has been processed and is presented on the cell surface membrane? HR
T helper cells will bind to the processed antigens and stimulate the B cells to divide by mitosis.
What is clonal selection?
Where certain B lymphocytes are cloned and all produce the same type of antibodies.
What are the two types of cells that the cloned B cells can turn into?
Plasma cells (Secrete antibodies into the blood plasma) and memory cells (circulate the blood and tissue fluid).
What is the primary immune response within the humoral response?
The cloned cells that mature into plasma cells.
What is the secondary immune response within the humoral response?
The cloned cells that mature into memory cells.
