6.5.1 Basic concepts of immunology Flashcards
What are the structure of the immune system (briefly)
White blood cells
Lymphoid tissues
What are the basic functions of the immune system?
Protect the host from
infection
Detection of infectious organisms
Destruction of infectious organisms
Remember what the infectious organism
What are the types of immunity?
Innate
Adaptive
Briefly describe innate immunity
Keeps foreign organisms out
Fast recognition and response to infection
Briefly describe adaptive immunity
More efficient but slower
Helps innate immune mechanism
What is an antigen?
Structural protein of a pathogen
Lymphocyte receptors recognise antigenic epitopes
What are the types of T cells?
T helper (CD4)
T killer (CD8)
Briefly describe the B cell receptor
Binds 2 antigens
Variable and constant regions
Binds to whole antigen on surface of pathogen in ECF
Briefly describe the T cell receptor
One arm, associated with many molecules
Variable and constant regions
TCR recognises digested antigen fragments displayed n surfaces of other cells
MHC complex presents to TCR
Describe lymphocyte development
Designs its own unique receptor
lock and key model
Describe the activation of lymphocytes
Lymphocytes leave primary lymphoid tissues and travel around body in circulation looking for antigen in secondary lymphoid tissues
T cells undergo clonal expansion
Describe the roles of the activated lymphocytes
B cells - produce antibodies
CD4 (T helper) cells - produce cytokines to activate other cells
CD8 (T Killer) cells - seek out and destroy virus-infected cells
What are antibodies?
Antigen-binding proteins
Targets external surface of pathogen
Once bound, it neutralises, attracts phaogytic cells, triggers innate killing response
Briefly describe memory lymphocytes
When infection is over and host has recovered we are left with expanded population of lymphocyte clones
Memory lymphocytes have long lifespan
