Secondary lymphoid tissues Flashcards
Where are secondary lymphoid tissues found?
In the sites where mature lymphocytes are exposed to and stimulated by antigen.
What are secondary lymphoid tissues also known as?
Peripheral lymphoid organs.
What do secondary lymphoid tissues include?
Lymph vessels
Lymph nodes
Spleen
Mucosa associated lymphoid tissue (MALT)
How do lymphocytes enter the secondary lymphoid tissues?
Via high endothelial venues (HEV), which express specific adhesion molecules on their endothelium to which lymphocytes bind. Adhesion then leads to lymphocyte squeezing through the endothelium into the node.
What do lymph vessels do?
Drain tissue fluid from connective tissue.
What is lymph?
Fluid and cells collectively.
How do lymph vessels empty?
Primarily via the thoracic duct to the subclavian vein.
How is unidirectional flow ensured?
By valves, so without an anatomical pump.
How are antigens and foreign materials carried to the lymph nodes?
Its drained from the site of infection (usually connective tissues) and is carried to lymph nodes.
