W6 - Lymphoreticular System Flashcards
Where do the T-cells go to mature?
Thymus
What increases in the thymus as you age?
Adipose tissue
What part of the thymus has majority T-cells?
Paracortex
What part of the thymus has majority B-cells?
B cells
What cells are found in the medullary cords of the lymph nodes?
Plasma cells
The germinal centres of the lymph node are equivalent to the ???? in the spleen?
White pulp
T-cells come from the bone marrow go to the thymus to mature, where on the thymus do they enter?
Corticomedullary junction
What is an MHC?
Major Histocompatibility Complex
What type of cells promote T-cell maturation?
Thymic nurse cells
What is the purpose of the medulla?
To remove T-cells that recognise the normal body as non-self
In the cortex/medulla of the thymus, is there +ve or -ve selection of T-cells?
Cortex +ve, medullary -ve
What do CD4 and CD8 cells do?
Helper and cytotoxic
What is the pink swirly material in a Hassall’s corpuscle?
KEratinised epithelial cells
How to differentiate between primary and secondary follicles in lymph nodes?
Primary - purple throughout, Secondary - have a light purple patch within
What cells are found in germinal centre of the secondary follicles?
Activated B-cells
What region of the lymph nodes are follicles found in?
Cortex
Where is the paracortex and what cells are found there?
Between/around follicles, T-cells
Germinal centres are present in the white pulp of the spleen too, what cells are found there?
B-cells
What does PALS stand for?
Periarteriolar Lymphoid Sheaths
What cells are found in the PALS?
T-cells
Dendritic cells have long cytoplasmic processes, why?
Increase surface area to present more antigens and closely associate to lymphocytes
MHC class 1 are found on all cells apart from…
RBCs
MHC class 1 antigens are presented to…
CD8 (cytotoxic T-cells)
MHC class 2 are found on ….
APCs only
What is the main function of the lymph nodes?
Generates and effective, adaptive immune response
THe LN have zones of B+T cells
