W1.2 Flashcards
Primary lyphoid organs
sites of production and maturation of immune cells (school)
bone marrow
development of all hematopoietic stem cells
Lymphoid line
B lymphocyte maturation
Natural Killer (NK) cell maturation
T cell precursors
thymus
maturation and selection of T lymphocytes
secondary lymphoid organs
potential sites for contact with foreign antigens (Work)
Harbor mature lymphocytes
Where foreign antigens activate lymphocytes
Includes spleen, lymph nodes, mucosal-associated lymphoid tissue
spleen
Largest secondary lymphoid organ
Tissue divided into 2 main types (red and white pulp
red pulp
function to destroy old RBCs
white pulp
Function - contains the lymphoid tissue and drains antigens from blood
lymph nodes
Function - filtration; generation of memory B-cells
Central collecting points for lymph fluid from adjacent tissues
Lymph fluid
filtrate of the tissue fluids
medulla
mostly contains macrophages/DCs (innermost)
paracortex
contains mostly T cells and some DCs (middle)
cortex
contains B cells organized in follicles (outermost)
Primary follicle
contains mature, resting B cells that have not yet been exposed to antigen
secondary follicle
consists of antigen-stimulated proliferating B cells (activated B cells form a secondary follicle
germinal center
interior of the secondary follicle; contains plasma cells, which actively secrete antibody, and memory cells, their precursors
Flow of lymph
Lymph from tissues (contains antigens form infection) → afferent lymphatics → medullary cords → efferent lymphatics
Other : high endothelial venues in the paracortical areas
steps of the immun response
Lymph from tissues (contains antigens from infection) comes in via afferent lymphatics
DCs and Macs in the medulla present antigens
EDCs activate T cells that are in the paracortex
Activated T cells give signals to promote cognate B cell proliferation in the follicles
MALT
one of the secondary lymphoid organs
