Talk:Draft 2016: Difference between revisions

Revision as of 18:22, 26 February 2016

Location throughout the entire body - concentrated in axilla, groin, lung, gastrointestinal tract mesenteries
Small (1 mm - 2 cm) encapsulated organ (diffuse lymphoid tissue - no capsule)
Antigen transformed lymphocytes from the blood
In lymph vessel pathways “filter” lymph
- Afferent - towards node (A - arrives at the node)
- Efferent - away from node (E - exits the node)

Mesenteric lymph nodes

Lymph Node Functions
In lymph vessel pathways “filter” lymph Immune - detect infections from peripheral tissues skin, respiratory tract, gastrointestinal tract, etc. secondary lymphoid organ return extracellular fluid to circulation

Lymph Node Structure

Fetal thymus	Young medulla	Young cortex

Connective Tissue

Capsule - dense connective tissue (irregular CT, some adipocytes))
Trabeculae - dense connective tissue
Reticular Tissue - Reticular cells and fibers, supporting meshwork (collagen type III)
- Reticular cell produces reticular fibers (collagen type III) and surrounds the fibers with its cytoplasm
- reticular fibbers can also be produced by fibroblasts

Important - Please note that the lymphocytes exit from the node by efferent lymphatic vessels.

‎‎Lymph Node 7

T and B motility

‎‎Lymph Node 8

T and B interaction

High Endothelial Venules

Links: Immunobiology - Figure 1.8. Organization of a lymph node

@@ Line 38: / Line 38: @@
 ! Lymph Node Structure&nbsp;
 |-
-|  '''Structure Overview'''
+| [[File:Lymph node structure.jpg|400px]]
-[[File:Thymus histology 06.jpg|400px|right]]
+| [[File:Lymph node cartoon.jpg|400px]]
-* Connective tissue capsule (thin) with numerous trabeculae (septa)
-** major blood vessels run in CT
-* Lobules containing '''cortex''' and '''medulla''' regions
-** medullary regions are continuous (connected together)
-* NOT supplied by afferent lymph vessels
-'''Blood-Thymic Barrier'''
-* Blood vessels are separated from thymus cortex by epithelioreticular cells.
-* impermeable to most macromolecules.
-* Barrier layers: capillary endothelium - endothelial basal lamina- perivascular CT sheath - basal lamina of epithelioreticular cells - epithelioreticular cell sheath
-{|
-|-bgcolor="F5FAFF"
-! Thymus Epithelioreticular cells (TEC)
-! Macrophages
-! Lymphocytes
 |-
-|
+| [[File:Lymph node cartoon 02.jpg|400px]]
-* Abundant, eosinophilic, large, ovoid and light nucleus 1-2 nucleoli
-* sheathe cortical capillaries
-* form an epitheloid layer
-* maintain microenvironment for development of T-lymphocytes in cortex (thymic epitheliocytes)
-|
-* cortex and medulla
-* difficult to distinguish from reticular cells in {{HE}}
-* remove auto-reactive  T-lymphocytes
-|
-* located in cortex and medulla
-* more numerous (denser) in cortex
-* majority are developing T-lymphocytes (= thymic lymphocytes or thymocytes)
-|}
 |}