<Li> Nucleases split nucleic acids into nucleotides . </Li> <P> In the human digestive system, the main sites of digestion are the oral cavity, the stomach, and the small intestine . Digestive enzymes are secreted by different exocrine glands including: </P> <Ul> <Li> Salivary glands </Li> <Li> Secretory cells in the stomach </Li> <Li> Secretory cells in the pancreas </Li> <Li> Secretory glands in the small intestine </Li> </Ul> <Li> Secretory cells in the stomach </Li>

Where are salivary amylase and gastric lipase first secreted and where do they become active