Digestive system of humpback whales with a keratinized stratified squamous epithelium which is continuous of the oesophagus epithelium. Due to the reflux of stomach juices from the main stomach, minor digestive activity takes place in the forestomach. The main stomach, also referred to as the fundic stomach, secretes mucus, protein digesting enzymes and hydrochloric acid to aid the breakdown of food and lined. The stomach lining is reddish–purple, highly convoluted and sometimes trabeculate epithelium. The pyloric stomach secretes enzymes that digest fat as well as alkaline chemicals to neutralize the stomach acid. It is the combined actions of these different compartments that allow whales to
Development of the digestive system signaling pathway secreted by gut endoderm and regulate the craniocaudal organization of the gut and its derivatives. The gut system extends from the oropharyngeal membrane to the cloacal membrane and is divided into the foregut, midgut, and hindgut. At the end of the third week, the neural tube, which is a fold of one of the layers of the trilaminar germ disc, called the ectoderm, appears. This layer elevates and closes dorsally, while the gut tube rolls up and closes ventrally to create a “tube on top of a tube.” The mesoderm, which is another layer of the trilaminar germ