九、消化: 人体吸收营养及排出废料的过程就是消化系统的作用。消化系统包括消化管和消化腺两部分。消化管包括口腔、咽、食道、胃、小肠、大肠和肛门。它起着物理性的消化作用。这些消化管接受食物后进行磨碎、搅拌,使食物与消化液充分混合,并将大块食物变成小块食物。消化腺分泌各种消化液,包括唾液腺、胃腺、胰腺和肝、肠腺。它起着化学性的消化作用。消化液中含有各种消化酶,将食物分解成最小的分子。如将 Nine, digestion: the body absorb nutrients and the process of discharging waste is the role of the digestive system. Digestive system, including digestive tract and digestive gland two parts. Digestive tract includes the mouth, pharynx, esophagus, stomach, small intestine, large intestine and anus. It plays a physical role in digestion. After receiving the food, the digestive tracts are ground and stirred to allow the food to be thoroughly mixed with the digestive juice, and the bulk food is turned into small pieces of food. Digestive glands secrete a variety of digestive juices, including salivary glands, stomach glands, pancreas and liver, intestinal glands. It plays a chemical digestion. Digestive juice contains a variety of digestive enzymes, the food broken down into the smallest molecules. If will