Structure and function of lymph node and spleen Flashcards
Lymph nodes and spleen are examples of…
secondary lymphoid tissues
What causes chylous ascites?
Obstruction to flow within lymphatic vessels
Lymph enters the node via…
afferent lymphatics
What are primary follicles?
Structures containing resting B cells
What are the functions of the lymphatic system? (2)
Return lymph to the circulation
Filter lymph before return to circulation
Where does lymph leaving the node drain to?
Ultimately the venous system via thoracic duct; emptied at junction of left or right subclavian and jugular veins
Lymph node cell populations:
a) predominant B-cell response
b) predominant phagocyte response
c) predominant T-cell response
a) autoimmune, infection
b) draining a tumour site
b) viral infections
What might be seen in cases of superficial infection?
Lymphangitis- red lines extending from an inflamed lesion
Where are T cells typically found within a lymph node?
In sheets surrounding the primary follicles; become more T-cell rich towards the medulla of the node
Where are plasma cells typically found within a lymph node?
Medulla
What does generalised lymphadenopathy suggest?
Systemic inflmmatory process or widespread malignancy e.g. lymphoma/leukaemia
Blood supply to the spleen (2)
Supplied by splenic artery; drained by splenic vein into the hepatic portal system
Parenchymal structure of the spleen (2)
Red pulp made of sinusoids and cords
White pulp
What is the function of red pulp?
Acts as a filter for old and damaged red blood cells
What does white pulp comprise and what is its function?
Peri-arteriolar lymphoid sheath (PALS). Mainly T cells; antigen presentation can occur here
Also lymphoid follicles
