منابع و مآخذ : ( ( 1 ) . قرآن مجيد آيه 12 و 13 سوره مباركه مومنون ، آيه 6 - 7 - 8 - سوره سجده ) ( ( 2 ) . J E Jirasek . Prenatal Development Obstetric and Gynecology , Siarra Volume 2 chapter 14 , 1991 ) ( ( 3 ) . Mrarjorie . A , Fetal of Development A Color Atlas of life before brith , page 188 - 194 , 1983 ) ( ( 4 ) . Caming Ham Macdonald . gumt : fetal Development . willams Textbook , Chapter 7 Appleton and long , 1977 )