Protein signalling in heart development Protein signalling in heart development The heart is the first functional organ in a vertebrate embryo. There are 5 stages to heart development. Specification of cardiac precursor cells: The lateral plate mesoderm delaminates to form two layers: the dorsal somatic (parietal) mesoderm and the ventral splanchnic (visceral) mesoderm. The heart precursor cells come from the two regions of the splanchnic mesoderm called the cardiogenic mesoderm. These cells can differentiate into endocardium which lines the heart chamber and valves and the myocardium which forms the musculature of the ventricles and the atria. The heart cells are specified in anterior mesoderm by
How Many More Times How Many More Times "How Many More Times" is the ninth and final track on English rock band Led Zeppelin's 1969 debut album "Led Zeppelin". The song is credited in the album liner to Jimmy Page, John Paul Jones, and John Bonham, but Robert Plant was later added to the ASCAP credits. At eight and a half minutes, "How Many More Times" is the longest song on the album. It is one of three Led Zeppelin songs on which Page used bowed guitar. In an interview he gave to "Guitar World" magazine in 1993, Page stated that the song "was