Whole cardiovascular system is derived from mesoderm(Heart,vessels,lymphatics,blood cells).
Different parts of heart are derived from different parts of mesoderm as given below.
- Parietal pericardium - somatopleural mesoderm
- Visceral pericardium - epicardium part of epimyocardial mantle
- Myocardium - myocardial(cardiac jelly) part of epimyocardial mantle
- Endocardium - endothelial lining
- Transverse pericardial sinus - dorsal mesocardium
- Cardiac cavity - cranial coelom,midline coelom and some part of intra embryonic coelom
Cardiac jelly
- Initially space between myocardium and endocaedium is filled with extracellular matrix called cardiac jelly which consist of type 1 & 4 collagen,fibronectin,laminin.
- This jelly gradually replaced by myocardium
- It plays major role in •cardiac looping•cell migration in septum and valve formation•hemodynamic performance•
SIGNIFICANCE OF HEART DEVELOPMENT
- TOF(tetralogy of fallot) : • occurs due to unequal division of conotruncal septum due to its anterior displacement. • components VSD,PS,Overriding aorta,RVH
- Persistent Truncus arteriosus :• due to failure of descend and fusion of conotruncal septum to ventricles • pulmonary artery is common opening to both ventricles + VSD
- Transposition of great vessels :•Due to failure of spiral descend of conotruncal septum and descends straight down • Aorta arises from RV and pulmonary artery from LV
