Cite this page: Pernick N. Normal: embryology. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/lymphnodesembryology.html. Accessed June 15th, 2019.
Definition / general
- Develop from lateral plate mesoderm (on either side of intermediate mesoderm)
- First, lymphatic sacs arise from endothelial outgrowths of large central veins at week 5
- Second, lymphatic plexus develops from lymphatic sacs
- Third, plexuses are invaded by mesenchymal cells that proliferate and aggregate to form lymph nodes
- Small collections of lymphoblasts are present by first trimester
- By second trimester, cortex is distinguishable from medulla and primary follicles are present