The digestive system, which is also known as the gastrointestinal tract, is a process where food is taken into the body through the mouth, which is then chewed and swallowed with the help of the mouths saliva glands. It then travels down the oesophagus into the stomach where there is gastric liquid to help break down the bolus so it ends up like a soup consistency, this then passes through the duodenum and carries on through the small and large intestine’s, and finally is dispersed into the blood system. Any substance that is left will be passed through the alimentary canal and will be eliminated as faeces.
Mouth, teeth, tongue
There are five main areas of the digestive system, these are ingestion, propulsion, digestion, absorption and elimination. This starts in the mouth where the chemical digestion process begins. When food and drink is taken into the mouth, three sets of salivary glands start the process of breaking down the food, these glands are called the parotid gland ( which is just under the ear ), The submandibular gland and the sublingual gland ( which are both under the tongue). Saliva is made up of mucus, water and an enzyme called salivary amylase. The saliva allows the food to be swallowed as it is a wet consistency, and it also keeps the mouth clean and away from any risk of infection. Food can be kept in the mouth for different periods of time, this is due to how much food is in the mouth at one time, and it can also depend on the different types of food, as some food is harder to chew which takes longer, for example, meat which is a form of protein, can take longer than vegetables or potato’s, which are a form of carbohydrates.
The enzymes are a clever part of the chemical digestion, as they break down the food so it becomes small enough to pass down the oesophagus, which is the hose pipe like tube which leads from the mouth down into the stomach. The tongue is made of muscle which is covered with membrane. It...