immunity and the immune system Flashcards
What is immunity?
all mechanisms used by the body as protection against environmental agents that are foreign to the body
What are the functions of the immune system?
immunological recognition
immune effector functions
immune regulation
immunological memory
How is the immune defence mediated?
coordinated responses - innate and adaptive immunity
What cells give rise to all red and white blood cells?
Haematopoietic stem cells (HSCs)
What are the two divisions of cells?
myeloid and lymphoid
What affects the maturation and differentiation of cells?
Colony-stimulating factors (CSFs)
What cells come from the myeloid lineage?
neutrophil
eosinophil
basophil
macrophage
dendritic cell
mast cell
What cells come from the lymhpoid lineage?
B and T cells and innate lymphoid cells
What do B and T cells express?
antigen-specific receptor (diversity)
What does each B cell express?
B cell receptor (BCR)
What can activated B cells act as?
professional antigen presenting cells (APC)
What are effector B cells called?
plasma cells
What do T cells express?
T cell receptor (TCR)
What is the role of TCR?
recognition of processed pieces of antigens bound to cell membrane proteins
or known as Major Histocompatibility complex (MHC) molecules
What are the phases of adaptive immunity responses?
antigen recognition
lymphocyte activation
antigen elimination
contraction (homeostasis)
memory
B cells arise in which organ?
bone marrow
T cells arise in which organ?
thymus
What are the secondary lymphoid organs and tissues?
lymph nodes, spleen and lymphoid tissues
What is the main function of bone marrow?
production of blood cells, maintenance of HSCs and modulation of skeletal remodelling
How are HSCs characterised?
self-renewal and pluripotency
How are thymocytes selected?
mature based on their TCR reactivity to self-MHC/peptide complexes
Where do antigens and antigen presenting cells enter?
afferent vessel
Where do Naive T cells enter?
high endothelial venules
Where do Naive T cells and APCs interact?
paracortex (T cell zone)
What do B cells interact with?
follicular dendritic cells
What happens when lymphocytes are activated by microbial pathogen?
T and B cells migrate to edge of follicles and, T helper cells interact with B cells to differentiate into antibody-producing cells
How do activated T and B cells leave the lymph node?
efferent lymphatic vessels
What is the role of the spleen?
trapping and responding to blood-borne antigens
How are antigens and lymphocytes carried into the spleen?
splenic artery
What are red pulps?
sinuses containing macrophages
What is the role of the macrophages in the red pulp?
phagocytose age/abnormal erythrocytes; recycling iron; and removal of microorganisms from bloodstream
What is the white pulp?
lymphoid tissues arranged around central arterioles
What are the different types of lymphoid tissues?
mucosal-associated lymphoid tissues
gut-associated lymphoid tissues
bronchus-associated lymphoid tissues
nasal-associated lymphoid tissues
skin-associated lymphoid tissues
