What happens when we ingests something?
The mouth is the first portion of the alimentary canal that receives food and saliva. The tongue tastes food, manipulates it during chewing and helps shape the food into a ball called a bolus. When an individual ingests something, the substance begins to make its way through the gastrointestinal tract in a process called digestion. Ingestion is the process of consuming something and taking it into the body. In humans, ingestion usually occurs through the mouth. Digestion of food begins in the mouth by chewing and mechanical fragmentation of food into smaller particles, which are easy to swallow. The presence of food in the oral cavity triggers a nervous reflex that causes the salivary glands to deliver saliva through ducts to the oral cavity. Saliva contains a slippery glycoprotein (carbohydrate–protein complex) called mucin, which protects the lining of the mouth from abrasion and lubricates food for easier swallowing. Saliva also contains buffers that help prevent tooth decay by neutralizing acid in the mouth, while antibacterial agents in saliva kill many of the bacteria that enter the mouth with food.
The tongue tastes food, manipulates it during chewing, and helps shape the food into a ball called a bolus. During swallowing, the tongue pushes a bolus to the back of the oral cavity and into the pharynx, a junction that opens to both the esophagus and the windpipe (trachea). When we swallow, the top of the windpipe moves up so that its opening, the glottis, is blocked by a cartilaginous flap, the epiglottis. This tightly controlled mechanism normally ensures that a bolus is guided into the entrance of the esophagus. At the end of the esophagus, the lower esophageal sphincter lets the food into the stomach.