Lymphoid Organs Flashcards
Central (primary) lymphoid organs
Bone marrow, thymus
Peripheral (secondary) lymphoid organs
lymph nodes, spleen, tonsils, Peyer’s patches
Extralymphoid tissues & organs:
gi., resp., urinary, repro., tracts, skin, blood & lymph, and wandering lymphocytes
Lymphocyte recirculation is carried out by;
The circulatory system (blood). Permits continuous immune surveillance and ensures rapid response to antigens
Pale staining cytoplasm with numerous processes, diffuse nucleus with prominent nucleolus. (hint: most originate from mesenchyme)
Reticular cell
These types of cell predominate in loose lymphoid tissue
Reticular cells (fixed cells)
These types of cell predominate in dense lymphoid tissue
Lymphocytes (free cells)
A lymphoid nodule that has not seen antigen and is not stimulated is called
A primary (lymphoid) nodule. Lymphoid nodules are not limited to lymphoid organs.
If the nodule is stimulated by antigenic stimulation it gets larger in size and develops a pale staining germinal center. What is this type of nodule now called
A secondary lymphatic nodule
The germinal center contains numerous
Activated B lymphocytes
The three types of lymphoid tissue are
Dense, loose, and nodular
In nodular lymphoid tissue the predominant cell type is
lymphocytes
In a germinal center the dark zone contains:
dividing B lymphocytes
In a germinal center the light zone contains:
Non-dividing B lymphocytes and helper T cells.
In a germinal center the functional correlation of the dark zone:
the proliferation of activated B lymphocytes (clonal expansion)
In a germinal center the functional correlation of the light zone:
Selection of B lymphocytes, apoptosis of B cells that cannot discriminate between self and non-self antigens, surviving B lymphocytes begin differentiation into plasma cells and memory B cells
In a germinal center the mantle zone contains:
young plasma cells and memory B cells
In a germinal center the mantle zone functional correlation is:
temporary storage of young plasma cells and memory B cells
Germinal centers appear after ____ and involute after about ____
primary antigenic response; 4 weeks
The concave surface of a lymph node contains the _____
Hilus
______ enter and leave at the hilus ______ leave at the hilus
Blood vessels; efferent lymphatics
Left off on slide 18
need to make more cards
