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
Human digestive system intestine. The mouth is the first part of the upper gastrointestinal tract and is equipped with several structures that begin the first processes of digestion. These include salivary glands, teeth and the tongue. The mouth consists of two regions; the vestibule and the oral cavity proper. The vestibule is the area between the teeth, lips and cheeks, and the rest is the oral cavity proper. Most of the oral cavity is lined with oral mucosa, a mucous membrane that produces a lubricating mucus, of which only a small amount is needed. Mucous membranes vary in structure in the different regions