Week 7 Lymph Part 2 Flashcards
List supporting cells for lymphatic system
Monocytes, basophiles, dendritic cells (DC), Epithelioreticular cells, macrophages, eosinophils, follicular dendritic cells, neutrophils, reticular cells, langerhan’s cell (in skin)
What does CD stand for?
Cluster of differentiation
What do CD markers do?
Refer to different antigens present on different cell types at different stages of cellular differentiation, VERY good for IDing or diagnostic reasons
How do you ID lymphocytes?
By use of CD markers from the standardized international system to denote where they are in the differentiation process. They all look similar to the eye, big nucleus, blue, little cytoplasm BUT the cell surface is VERY different.
Why do CD markers work as identification?
Because some markers are only expressed throughout a cell’s lifespan and others are only present at specific phase of differentiation
Lymphatic vessels begin as a network of?
Blind capillaries in the loose connective tissue; blind= collect fluid and antigens
Describe lymphatic capillaries location?
More porous than blood capillaries, abundant in the papillary layer of dermis in the skin and in mucous membranes
The purpose of lymphatic capillaries is to?
Provide a collection point to drain and collect lymph from extracellular spaces
What is “lymph”?
Fluid, antigens, other ECM substances
As the lymph passes through the _____ ____ the lymphocytes have access to antigens
Lymph nodes
Lymphocytes circulate in both ____ and ______ vessels
Lymphatic and blood vessels
Lymph enters the lymph nodes via _____ lymphatic vessels?
Afferent
Lymphocytes in the blood enter the lymph node via?
Post capillary venules (high endothelial venules)
Lymphocytes T and B cells populate the same or different regions of the lymph node?
DIFFERENT
Lymphocytes and lymph leave the node via?
Efferent lymphatic vessels
What is the Hilum?
The location of lymph vessels and blood vessels entering of leaving the lymph node
What actually happens in lymphoid tissue?
Immune reactions are occurring and the mechanics of the immune signaling are taking place
What is diffuse lymphoid tissue?
A loose collection of T and B cells in no particular order/organization
Where is diffuse lymphoid tissue found?
In alimentary canal, respiratory passages, genitourinary tract
What is the alimentary canal?
Digestive tract from mouth to anus
Diffuse lymphoid tissue is composed of a variety of what cells?
Lymphocytes, resident & transitory macrophages, plasma cells, monocytes, eosinophils
We know diffuse lymphoid tissue is highly active for 2 reasons
1) The regular presence of high numbers of plasma cells (especially MALT)
2) The large # of eosinophils are indicative of chronic inflammation and hypersensitivity reactions
Lymphoid tissue forms?
Lymphatic nodules or lymphatic follicles
Primary nodule
Is mainly composed of lymphocytes
Secondary nodules are composed of two main features
1) germinal center and 2) mantle zone/corona
What is the germinal center?
A lightly staining center corresponding to large immature lymphoblasts and follicular dendritic cells
Mantle zone or corona
A ring of small mature lymphocytes around the germinal center
What are specific location that aggregations of lymphatic nodules/follicles are found?
Tonsils, peyer’s patch, and vermiform appendix (these are classic locations)
Tonsils
Ring of lymphatic tissue and the entrance of the oropharynx -dense accumulation of lymphatic tissue in the mucous membrane
Peyer’s patches
In the ileum (distal portion of the small intestine) -can see distinct white patches on surface
Vermiform appendix
Arises from the cecum
