Final answer:
A feeding tube inserted through the mouth and extending to the stomach is known as a nasogastric (NG) tube. It traverses the esophagus, which is a crucial component of the human monogastric digestive system.
Step-by-step explanation:
A feeding tube inserted into the oral cavity and leading down to the stomach is called a nasogastric (NG) tube. This type of tube is typically used to provide nutrition to a person who cannot eat by mouth. It traverses the esophagus, a long, narrow, tube-like digestive organ that allows a bolus of food to pass from the pharynx to the stomach using wave-like muscle contractions called peristalsis. The process is an essential part of the monogastric digestive system, which in humans includes the entire gastrointestinal tract spanning from the mouth to the anus, facilitating digestion and absorption of nutrients.