Development of the digestive system As a result of the cephalocaudal and lateral folding of the embryo, a portion of the endoderm-lined yolk sac cavity is incorporated into the embryo to form the primitive gut. In the cephalic and caudal parts of the embryo, the primitive gut forms a tube, the foregut and hindgut, respectively. The middle part, the midgut, remains temporally connected to the yolk sac by means of the vitelline duct. The foregut gives rise to the esophagus, the trachea, lung buds, the stomach, and the duodenum proximal to the entrance of the bile duct. In addition, the liver, pancreas, and biliary apparatus
The Hardest Part Is the Night The Hardest Part Is the Night "The Hardest Part Is the Night" is a single by American rock band Bon Jovi. It is taken from their second album, "7800° Fahrenheit". It is notable for being the first Bon Jovi single to be released in the UK, where it charted at #68. It was the only single from the album not to chart in the U.S. Among Bon Jovi's early songs, "The Hardest Part is the Night" is the one that expresses most clearly Jon Bon Jovi's concerns with working class issues and the struggles of the underdog, a theme that