It is a part of the gastrointestinal tract, The tubular organs which make it up are represented by the salivary glands and the liver, One of its functions is the regulation of blood plasma volume

It consists of the parietal peritoneum, continuing with the visceral peritoneum which lines the abdominal cavity, It consists of a double-stratified mesentery, It contains mucus-secreting glands which serve to protect the tissues of the gastrointestinal tract

It communicates anteriorly with the oropharynx and it has no gustatory function, The palate of the oral cavity consists of the hard palate and the soft palate, It mixes food with gastric secretions, and it has a gustatory and a masticatory function

Is covered by the tooth’s crown and covers dentin, It is very hard, but not as hard as dentin, Forms the largest part of the tooth

Mainly consists of hydroxyapatite, having the same hardness as enamel, Contains blood vessels, nerves and the tooth’s connective tissue

The oesophagus is the first segment which displays the three layers of the gastrointestinal tract, The oesophagus extends to the pyloric sphincter, where the stomach begins