Endocrine - Thymus Development
From Embryology
Lecture - Head Development | UNSW Embryology - Thymus Development
The thymus has two origins for the lymphoid thymocytes and the thymic epithelial cells. The thymic epithelium begins as two flask-shape endodermal diverticula that form from the third pharyngeal pouch and extend lateralward and backward into the surrounding mesoderm and neural crest-derived mesenchyme in front of the ventral aorta.
- Thymus - bone-marrow lymphocyte precursors become thymocytes, and subsequently mature into T lymphocytes (T cells)
- Thymus hormones - thymosins stimulate the development and differentiation of T lymphocytes
Thymus Development
- Endoderm - third pharyngeal pouch
- Week 6 - diverticulum elongates, hollow then solid, ventral cell proliferation
- Thymic primordia - surrounded by neural crest mesenchyme, epithelia/mesenchyme interaction
