Upper gastrointestinal organs, i.e., the organs of the digestive tract from the beginning of the mouth to above the flexor ligament, mainly include the oral cavity, pharynx, esophagus, stomach, duodenum, liver, pancreas, and gallbladder. 1. Oral cavity: secretes salivary amylase to help digest carbohydrates, as well as antibacterial, assisting respiration and other functions; 2. Pharynx: vocalization, defense against bacterial and viral invasion, and assist in breathing; 3. Esophagus: the passage of food, no digestive effect, help food into the stomach; 4. Stomach: an important digestive organ of the human body, can secrete gastric juice to help digest protein; 5. duodenum: connected to the stomach, can receive bile bile, secretion of duodenal fluid to help digestion and absorption; 6. Liver: an important digestive organ of the human body, with detoxification, secretion, digestion and other physiological functions; 7. Pancreas: can secrete pancreatic fluid to help the body digest and absorb food, but also can secrete insulin, glucagon to regulate blood sugar; 8. Gallbladder: can concentrate and store bile. Upper gastrointestinal organs play a very important role in the process of digestion and absorption in the human body, once any discomfort occurs, it is necessary to seek medical treatment as soon as possible to avoid the deterioration of the development of the disease.