Histology of the lymphoid system Flashcards
What are some of the traits of the thymus
histologically
The thymus has multiple lobules, each with a cortex and a medulla
The cells traverse from the medulla to the cortex as they mature into T cells
What other cells does the thymus contain
other than T cells
Stellate, epithelial reticular cells, some reticular fibres, dendritic cells, macrophages and some WBC
What kind of cells are hassals corpuscles and in which organ are they found?
hassals corpuscles are flattened whirls of acidophilic cells found in the medulla of thymus lobules
What layer is found between the cortex and the medulla in the bursa of fabricius?
layer of undifferentiated epithelium-derived cells called the capillary layer
What is found on the apex of the bursa of fabricius?
tall pale columnar epithelial cells called the ‘epithelial tuft’ and lytic enzymes
What is found below the epithelial tuft in the bursa of fabricius?
pseudostratified columnar cells and then lamina propria below that
What kind of epithelium do peyers patches have and what is the function?
specialised follicle-associated epithelium that contains numerous microfolds specialised for antigen uptake
What is the capsule and trabeculae of lymph nodes made up from?
It is made up of connective tissue
What is the medullary cord?
Parts within the medulla of the lymph nodes that contains lymphocyes, macrophages and plasma cells
What kind of cells are found in the paracortex of the lymph node medulla?
T-helper cells and T-cytoxic cells
What is the main entry and exit point of B and T lymphocytes
The high endothelial venules
What do HEV’s look like?
simple cuboidal epithelium, and they express receptors for antigen-primed lymphocytes
What is the spleen categorised by?
Contains smooth muscle in its capsule and has a meshwork of trabeculae
What does the white pulp in the spleen contain?
lymphoid tissue that surrounds arterioles
What does the red pulp in the spleen contain?
loose vascular framework
