Embryology in the Quran: Difference between revisions

A very detailed account of musculo-skeletal development in the human limb by clinical-geneticist Robert Jan Galjaard covers this subject.<ref>Galjaard, R.J.H. [http://repub.eur.nl/res/pub/10474/030924_Galjaard,%20Robert-Jan%20Harmen.pdf Mapping Studies of Congenital Limb Anomalies]. Ablasserdam: Haveka, B.V., 2003, page 16 [http://www.webcitation.org/6lFwBQq9z webcitation archive link]</ref> It details that muscle precursor cells migrate from the somites into the limb buds (ca. day 26). This is well before the condensing core of mesenchyme has started to chondrify into cartilage bone models in the upper part of the upper limb (ca. day 37), followed by the lower part (ca. day 41). The myoblasts have grouped into distinct dorsal and ventral masses by that stage (they do so in the upper limb by day 36 and the start of chondrification according to Sivakmur et. al<ref>Sivakumar, B. et. al. ''Congenital Hand Differences'' in Farhadieh, R. et. al. (ed.) Plastic and Reconstructive Surgery: Approaches and Techniques, Chichester: Wiley, 2015, p.660 [https://books.google.co.uk/books?id=tCq9BgAAQBAJ&pg=PA660#v=onepage&q&f=false Google books preview]</ref>). The upper limbs later start to ossify (ca. day 54). Chondrification of mesenchyme, the grouping of myogenic masses, and ossification all occur in a proximal-distal order (upper to lower part of each limb). The digits of the hands only start to chondrify ca. day 51.