The digestive system prepares food for use by hundreds of millions of body cells. The gut modifies food physically and chemically and disposes of unusable waste. Mouth Mouth Food enters the digestive system via the mouth or oral cavity, mucous membrane lined. Communication with nasal cavity behind soft palate.
Floor is muscular tongue.
Swallowing involves co-ordinated activity of tongue, soft palate pharynx and oesophagus. After this the process is reflex. The tongue blocks the mouth, soft palate closes off the nose and the larynx rises so that the epiglottis closes off the trachea. Food thus moves into the pharynx and onwards by peristalsis aided by gravity. If we try to talk whilst swallowing food may enter the respiratory passages and a cough reflex expels the bolus.