a part inside the body of a person, an animal or a plant, that is shaped like a bag, has thin skin around it, and contains liquid or air （人、动植物体内的）囊，液囊，气囊
a part inside the body of a person, an animal or a plant, that is shaped like a bag, has thin skin around it, and contains liquid or air （人、动植物体内的）囊，液囊，气囊