Digestion – A food journey through the body

Digestion begins in the mouth, with thanks to our saliva. You are undoubtedly familiar with the concept of “mouth-watering“ looking at food. This image is more than just metaphorical: even before eating, saliva (or “water“) production is triggered in special glands in the mouth. This reflex is spontaneous. When we then go on to chew our food, the flow of saliva is stimulated further. Did you know that we produce around 1 – 2 litres of saliva per day? Saliva moistens the food and contains enzymes, such as lysozyme, which has an antibacterial effect. Saliva also contains the enzyme salivary amylase, which breaks down complex carbohydrates (oligo- and polysaccharides) in bread and pasta into smaller components down to simple sugar molecules (disaccharides). You can "observe" this process yourself by consciously chewing a piece of bread for a while until you notice it starts to taste sweet. 

When we swallow, the moistened food bolus is guided into the stomach by a wave-like contraction of the approx. 25 cm long oesophagus. During this process both the soft palate (connection to the nose and throat region) and the epiglottis (connection to the oesophagus) are closed in order to prevent the food bolus from taking the wrong route and entering the oesophagus. The  entrance to the stomach is opened via a reflex on swallowing, before being closed again immediately after. If this closure does not take place straight after swallowing, “acid reflux“ may occur. Perhaps you've experienced this before - when it happens, the sour content of our stomach enters the oesophagus.
To find out what happens next, read the article entitled “Digestion – A food journey through the body (stage 2: the stomach)“.