Histology Of Lymph Nodes Flashcards
(20 cards)
What are lymph nodes?
Small, bean-shaped secondary lymphoid organs found along lymphatic vessels, acting as filters for lymph and sites for immune activation.
What are the major components of a lymph node?
Capsule, cortex, paracortex, medulla, and hilum.
What is the function of the capsule in a lymph node?
It is a dense connective tissue that encloses the lymph node and sends trabeculae into its interior for support.
What is found in the outer cortex of a lymph node?
Lymphoid follicles with germinal centers, primarily containing B cells.
What is the paracortex, and which cells predominate there?
The deep cortex of the lymph node; it is rich in T lymphocytes.
Q: What structures are found in the
medulla of a lymph node?
A: Medullary cords (rich in plasma cells) and medullary sinuses.
Q: What is the function of the hilum in a lymph node?
It’s the entry/exit point for blood vessels and efferent lymphatics
Flashcard 8
Q: What are high endothelial venules (HEVs) and where are they located?
A: Specialized postcapillary venules in the paracortex that facilitate lymphocyte entry from the bloodstream into the lymph node.
What types of sinuses are present in lymph nodes?
A: Subcapsular, trabecular (intermediate), and medullary sinuses.
Q: What is the flow pathway of lymph through a lymph node
A: Afferent lymphatics → subcapsular sinus → trabecular sinuses → medullary sinuses → efferent lymphatic at the hilum.
Flashcard 11
Q: What is the primary function of lymph nodes in immunity?
A: To filter lymph, trap antigens, and provide an environment for antigen presentation and lymphocyte
Q: What are germinal centers and when do they appear?.
A: Light-staining areas in secondary lymphoid follicles where activated B cells proliferate, differentiate, and undergo somatic hypermutation
Q: Which cells support the lymph node structure and function?
A: Reticular cells and reticular fibers (type III collagen
Flashcard 14
Q: What is the role of dendritic cells in lymph nodes?
A: They present antigens to T cells in the paracortex to initiate immune responses
Q: What are medullary cords composed of?
Closely packed lymphocytes, plasma cells, and macrophages
Q: Which vessels bring lymph into the lymph node?
A: Afferent lymphatic vessels.
Flashcard 17
Q: Which vessels carry lymph away from the lymph node?
A: Efferent lymphatic vessels
Which type of immune response is initiated in the lymph node cortex?
The humoral immune response, involving B cells and antibody production
How do lymphocytes enter the lymph node from blood circulation?
Through high endothelial venules (HEVs) in the paracortex.
Flashcard 20
Q: What histological feature distinguishes the cortex from the medulla?
A: The cortex contains densely packed follicles, while the medulla has cords and sinuses with less densely packed cells.
