Which of the following statements is incorrect? the tongue is in direct contact with ingested food, but is still considered to be an accessory digestive organ. the esophagus is a muscular tube that is considered to be part of the gastrointestinal tract. the salivary glands are accessory digestive organs that secrete digestive enzymes into the oral cavity. the gallbladder is a hollow muscular organ that is considered to be part of the alimentary canal. the liver is an accessory digestive organ that produces secretions that flow into the small intestine.