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
Digestive biscuit in some varieties. A digestive biscuit averages around 70 calories, although this sometimes varies according to the factors involved in its production. Digestive biscuits are frequently eaten with tea or coffee. Sometimes, the biscuit is dunked into the tea and eaten quickly due to the biscuit's tendency to disintegrate when wet. Digestive biscuits are one of the top 10 biscuits in the United Kingdom for dunking in tea. The digestive biscuit is also used as a cracker with cheeses, and is often included in "cracker selection" packets. In the UK, McVitie's digestive is the best selling biscuit, with 80 million