Lymphoid Structures I Flashcards
What type of lymphoid organ is a lymph node?
A secondary lymphoid organ (p.192)
How many afferents and efferents does a lymph node have?
Many afferents; one or more efferents (p.192)
Describe the basic structure of a lymph node.
Encapsulated with trabeculae (p.192)
What are the three functions of a lymph node?
Non-specific filtration by macrophages, storage and activation of T and B cells, antibody production (p.192)
What is the primary function of the lymph node follicle?
Site of B-cell localization and proliferation (p.192)
Where are lymph node follicles located?
In the outer cortex (p.192)
Compare primary and secondary lymph node follicles.
Primary follicles are dense and dormant; secondary follicles have pale central germinal centres and are active (p.192)
What is the medulla of a lymph node composed of?
Consists of medullary cords and medullary sinuses (p.192)
What are medullary cords?
Areas of closely packed lymphocytes and plasma cells (p.192)
What cell types does the medulla of a lymph node contain?
Macrophages and reticular cells (p.192)
How does the medulla of a lymph node communicate with efferent lymphatics?
Via medullary sinuses (p.192)
What is the function of a lymph node paracortex?
Houses T cells (p.192)
Where is the paracortex of a lymph node located?
Region of cortex between the follicles and the medulla (p.192)
What does the paracortex contain?
High endothelial venules through which T and B cells enter from the blood (p.192)
How does the paracortex change size in response to environmental stimuli?
In an extreme cellular immune response (i.e. viral) the paracortex becomes greatly enlarged (p.192)
