Anatomy, Physiology and Pathology Flashcards
What 3 site produce B cells in the fetus?
bone marrow, spleen, liver
Which interleukin is a growth factor produced by stromal cells in the bone marrow and thymus and is required for B and T cell development?
IL-7 (IL-7Rα is a form of SCID)
Where do B cells undergo negative selection?
bone marrow
These small bodies of granular cells surrounded by concentric layers of modified epithelial cells are found in the medulla of the thymus.
Hassall’s corpuscles
The thymus is formed from what kind of embryonic tissue and from which pharyngeal pouches?
endoderm and mesoderm, third and fourth pharyngeal pouches
In which portion of the thymus do T cells undergo the final states of maturation?
Medulla
What is positive selection and where does it take place?
ensures T cells are able to respond to self MHC; occurs in the cortex
Where does T cell negative selection occur?
starts in the cortex (eliminates autoreactive) and finishes in the medulla (contributes to self tolerance)
What disease is associated with congenital thymic aplasia?
DiGeorge Syndrome (SCID)
Which immunodeficiency (hypogam) is associated with a thymoma in adults?
Good’s syndrome
Where are the majority of B cells located in the lymph node?
follicular area of the cortex
Where are the majority of T cells located in the lymph node?
parafollicular areas of the cortex
What is the difference between a primary and a secondary follicle in a lymph node?
A secondary follicle has a germinal center while a primary does not
Which chemokines bind to CCR7 on T cells and attract them from the blood, through HEV and into the T cell zone of the lymph node?
CCL19 and CCL21
The absence of a spleen leads to increased susceptibility to what kinds of organisms?
encapsulated - Neisseria meningiditis, H. flu, strep pneumo
