The Lymphoid system Flashcards
What can APCs be
Macrophages or dendritic cells
What do APCs do
1) phagocytose intruders and remnants of disintegrated cells
2) Fragment ingested proteins and present fragments on MHC molecules on surface
What are the type of T lymphocytes
T helper
Cytotoxic T
Memory T
What are the type of B lymphocytes
Plasma cells
Memory B cells
How are antibodies produced through the action of T cells and B cells
- APC ingests bacteria and digested by lysosomal enzymes into SMALL PEPTIDE FRAGMENTS
- Small peptide fragments loaded onto HMC class 2 proteins
- HMC class 2 proteins are presenters
- T cell and APC talk via cytokines because they are bound
- CLonal multiplication of T cells with identical receptors
- random B cells floating around can also phagocytose and become APC
- T helper cell fits onto B cell and this leads to multiplication of B cells (clonal amplification)
- MAjority of B cells become plasma cells
- Antibodies bind to bateria
- this attracts T cells and other cells that activate the system
Where are APCs found
All exposed surfaces
Also tissues
What are ‘matching venues’
Secondary lymphoid system
What does the secondary lymphoid system include
- lymph follicles
- tonsils
- lymph nodes
- spleen
What do ‘matching venues’ look like in histological stains
As aggregates of thousands of lymphocytes
What are Matching Venues the main site of
Antigen presenting and T and B cell activation and expansion
What are Matching Venues kept in shape by
Reticular fibers that allow lymphocytes and APCs to circulate around them
When are capillaries leaky
Slightly leaky as liquid passed out into interstitial tissue
Where does the ‘leaking’ from capillary go to
-where does this go in turn?
Collected in lymph capillaries with come together to form a larger lymph vessels
Once in larger lymph vessels, where does the liquid go
Ends up in subclavian veins
What are there between subclavian veins and what do these do
Lymph nodes where lymph is checked by APCs
