Lymphoid Tissue Flashcards
What is adaptive immune system
Added form of defense high specificity and that is based on presence of trillions of lymphocytes
What is the major role of this high specificity adaptive immune syst
Destruction and abilit to distinguish self and non self
What happens when the immunes system fails to recognise self and non self
Results in auto immune disease such as rheumatoid arthritis
Myasthenia gravis and Graves’ disease
What is a primary liymphoid organ
Site lymphocyte prod and maturation
Bone marrow and thymus
What is a secondary lymphoid organ
Sites which lymphocytes migrate and where they aggregate in large numbers
Organs such as spleen, lymph nodes and lymph nodules
What’s re th three principle forms lymphocytes come in
B cells
T cells
Natural killer cells
What are B cells
They produce antibodies develop to plasma cells to do this
What are T cells
These participate in cellular immunity come to play when cells attacked by antigens and are found in helper, cytoxic and suppressor forms
What are natural killer cells
The cells kills virus infected cells and some tumour cells
Development of T cells
T cells prod in brow form stem cells
Immature T cells migrate to thymus to mature and be educated
Through bloodstream again to secondary lymphoid organs and organs
Development of B cells
B cells remain in bone marrow where prod and are developed here
Through bloodstream to secondary lymphoid organs
Where is the thymus located
Mediastinum
When does tend thymus increase size and then what happens
Increase form birth to puberty
Then recess becomes more fatty
What is the fate of T cells when in the thymus
Leave blood vessels enter cortex of thymus and begin prolif maturation and selection process
Those that fail will undergo apoptosis and phagocytosed
What happens to T cells that survive the cortex
Enter the medulla
They interact with epi cells and presented with self antigens
Any cells activated by self are clonally deleted
