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 disc, holds the tubes together and the lateral plate mesoderm, the middle layer of the germ disc, splits to form a visceral layer associated with the gut and a parietal layer, which along with the overlying ectoderm, forms the lateral body wall. The space between the visceral and parietal layers of lateral plate mesoderm is the primitive body cavity. When the lateral body wall folds, it moves ventrally and fuses at the midline. The body cavity closes, except in the region of the connecting stalk. Here, the gut tube maintains an attachment to the yolk sac. The yolk sac is