[W3] Anatomy of the immune system Flashcards
(29 cards)
What are the four main tasks of the immune system?
Immunological recognition, effector function, regulation, and memory.
What are the primary lymphoid organs?
Bone marrow and thymus.
What is the function of bone marrow in immunity?
Produces all blood cells and is the site of B cell development.
What is the function of the thymus?
Site of T cell maturation and elimination of self-reactive T cells.
What do haematopoietic stem cells differentiate into?
Myeloid (innate) and lymphoid (adaptive) lineages.
What are thymocytes?
Immature T cells that develop in the thymus.
What is central tolerance in B and T cell development?
Elimination of self-reactive lymphocytes through apoptosis.
What are secondary lymphoid organs?
Lymph nodes, spleen, and MALT.
What is the main role of the lymphatic system?
Drains interstitial fluid, filters lymph, and transports it back to blood circulation.
What does the thoracic duct do?
Returns lymph to the blood via the subclavian vein.
Where do B cells and T cells interact in lymph nodes?
In germinal centres, B cells meet CD4+ T helper cells.
What happens to activated B cells in lymph nodes?
They proliferate and differentiate into plasma cells.
What does the spleen filter?
Blood (not lymph).
What are the two compartments of the spleen?
Red pulp (removes old red cells), white pulp (immune responses).
What is PALS in the spleen?
Periarteriolar lymphoid sheath, where T cell activation occurs.
What is MALT?
Lymphoid tissue in mucosal surfaces (e.g. GI, respiratory tract).
What are Peyer’s patches?
Lymphoid follicles in the intestine containing B and T cells.
What do M cells do in Peyer’s patches?
Transport antigens from the gut lumen to immune cells.
Where are the three types of tonsils located?
Lingual (tongue base), palatine (sides of mouth), pharyngeal (adenoids).
What is the main function of tonsils?
Defend against pathogens entering via mouth and nose.
What innate immune cells reside in tissues?
Macrophages and dendritic cells.
How do T cells reach infection sites?
Travel from lymph nodes via blood; attracted by chemokines.
What are tissue-resident memory T cells?
CD4+ or CD8+ T cells that remain in tissues to provide local immunity.
What are tumour-infiltrating lymphocytes (TILs)?
CD8+ cytotoxic T cells that detect and destroy cancer cells.
