Lecture 7 Flashcards
What are high endothelial venules?
The region in which lymphocytes leave the blood stream
What is the main lymphatic vessel which takes the lymph back to the blood?
The thoracic duct
What is the point of the continuous circulation of lymph?
To ensure that the correct lymphocyte will encounter antigens and allow circulation of the resulting activated cells
What are the four effector responses of the lymphocytes?
Anti body production, Antigen-specific cytotoxicity, Antibody-dependant cell mediated cytotoxicity, Natural Killer cell activity
What are the regulatory responses of lymphocytes?
Cytokine production
Do effector responses last forever?
No they degrade, but immunological memory will allow a more vigorous rapidly secondary response
What region on the immunoglobulin molecule has a high affinity for neutrophils?
The CH3 domain
What connects the heavy and light chains?
Disulphide bonds
What is the purpose of the hinge region of the immunoglobulin molecule?
To allow the immunoglobulin to change from a Y to a T shape
What is the CH2 region responsible for?
Where complement proteins can bind to
What do primary antibody responses result from?
When an unactivated antigen sensitive B cells come into contact with its specific antigen
What do secondary antibody responses result from?
Activation of long lived memory B lymphocytes
Where does the activation for primary and secondary immune responses occur?
Secondary lymphoid organs
What does activation of antigen sensitive B lymphocytes result in?
Maturation of B lymphocytes into plasma cells and a few memory cells
What is the function of plasma cells?
To secrete the specific antibodies which act against the antigens of the pathogens
Do memory cells last forever?
No
What causes antigen sensitive B cells to proliferate into plasma and memory cells?
When an antigen brought to the secondary lymphoid organ by an antigen presenting cell WITH the addition of helper signals in the formation of hormones and cell surface interaction
What are the four methods that antibodies aid in the immune response?
Direct neutralisation, Complement activation, oponisation, antibody-dependant cell-mediated cytotoxicity
How do antibodies aid in cell cytotoxicity?
K lymphocytes recognize the Fc region of antibodies allowing them to recognise and kill pathogens
How do K lymphocytes recognise pathogens?
Through use of receptors for C3b and Fc regions of immunoglobulins
How do K lymphocytes kill cells?
Through use of short range cytotoxicity factors NOT phagoctyosis
How do complement proteins become activated?
Through bacterial cell wall components or through antigen-antibody complexes
What are the two pathways in which the antigen-antibody complex and the complement system act?
The classical pathway and the alternative pathway
What is the classical pathway?
When antibodies-antigen complexes activate the complement system
What is the alternative pathway?
When the complement system is activated by bacterial cell wall components
What are the three basic functions of the complement immune system?
Chemotaxis, Oponisation and lysis
