Final Exam Flashcards
(199 cards)
Where do naive lymphocytes in the blood migrate to?
Secondary lymphoid tissues
Where do effector and memory T cells in the blood migrate to?
Site of infection
What are HEVs and what is their function?
High endothelial venules - specialized blood vessels which facilitate extravasation of lymphocytes into the lymph node
What are distinctive characteristics of HEVs (as compared to regular venules)?
Tall endothelial cells
Thick basal lamina
Concentrically arranged reticular fibroblasts making up a perivascular sheath
Increased expression of molecules associated with cell migration into lymphoid tissues
What are the four primary stages of lymphocyte trafficking from blood vessel to tissue, and which molecules facilitate them?
Rolling - Selectins
Activation - Chemokines
Adhesion - Integrins
Diapedesis - Chemokines
What are the three classes of molecules grouped as “adhesion molecules”?
Selectins, chemokines, integrins
What are chemokines and what is their function?
Small soluble (secreted) proteins. Chemoattractants for immune cells
What are selectins?
Cell surface proteins, allow for extravasation of immune cells
What are integrins?
Cell surface proteins, allow immune cells to migrate to specific tissues
What is monocyte-chemoattractant protein 1?
Mucosal homing receptor - Regulates migration and infiltration of monocytes/macrophages
What are the primary lymphoid organs?
Thymus, bone marrow/bursa fabricius, Ileal Peyer’s patch, lymphoglandular complexes
What are the (groupings of) secondary lymphoid organs?
Lymph nodes, spleen, tonsils, Peyer’s patches
Which part of the thymus is most densely packed with lymphocytes?
Cortex (outer part)
What is Hassal’s corpuscule?
Structure in the thymic medulla containing a blood vessel with very thick walls preventing antigen from entering the thymus.
What is the bursa fabricius and where is it located?
Primary lymphoid organ (source of B cells AND traps antigen) in birds. Round sac with a connecting duct to the cloaca
What are the two types of Peyer’s patches and what is the difference between them?
Ileal patch - site of lymphocyte (B cell) development
Jejunal patches - secondary lymphoid organ
What is the mammalian equivalent to the bursa fabricius?
Ileal peyer’s patch
Which animals do not have lymph nodes?
Birds
What are the residential cells of lymph nodes?
(Follicular) dendritic cells, follicular T helper cells
Which cells are located in the cortex vs. paracortex of the lymph nodes?
T cells in paracortex
B cells in cortex (follicles)
Where is the germinal center visible in the lymph node?
Round structure near the junction of cortex and paraxortex
Which B cell-related processes occur in the dark zone vs. light zone of the germinal center?
Dark zone - Somatic hypermutation
Light zone - Testing of antibody affinity
What is the primary cell type found in the subcapsular sinus of lymph nodes?
Macrophages
What are the three immune-related structures in tonsils/Peyer’s patches and which cell types are they associated with?
Dome region - macrophages and DCs
Follicles - B cells, follicular DCs/Th cells
Interfollicular region - T cells