Lymphoid Tissues Flashcards
What are some primary lymphoid organs?
Thymus
Bone marrow
Foetal liver
What happens in the primary lymphoid organs?
Where lymphocytes are produced —> lymphopoieses
What compromise the adapt olive immune response?
B cells
T cells
What are the hallmarks in the adaptive immune system?
Specificity —> provided by a vast range of unique T cell and B cell receptors
Memory —> rapid expansion in response to secondary encounter
What is the primary site of haematopoiesis?
Bone marrow —> mostly flat bones
What is red and yellow bone marrow?
Red —> produces blood cells
Yellow —> fat
Where do T cells go to from the bone marrow?
Thymus
What happens in the thymus?
T cell selection —> stepwise differentiation
- positive selection —> can the T cell receptor signal
- negative selection —> does it react against our own body
Final selection and exit
Where do B cells develop?
Bone marrow
Where do T cells develop?
Thymus
What are some secondary lymphoid organs?
Spleen
Lymph nodes
Appendix
Mucosal associated lymphoid tissue
What happens in the secondary lymphoid organs?
Where lymphocytes can interact with antigens ans other lymphocytes
What do lymph nodes and the spleen contain?
Distinct T and B cell zones
Afferent lymph
Efferent lymph
Arterial and venous connection
What are epithelial barriers?
First line of defence against infection
Physical barrier
Extensive lymphatic network
What is the specialised secondary lymphoid tissue in the gut?
Peyer’s patches
Follicle highly enriched with B cells and contains high frequency of germinal centres
