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Human Body Study

Mouth

The entrance to the digestive tract, where digestion begins. Also called the oral cavity.

The digestive tract The GI tract from mouth through oesophagus, stomach, small intestine and large intestine, with liver, gallbladder and pancreas as accessory organs. Each label links to the article for that part. Mouth Esophagus Liver Stomach Gallbladder Pancreas Small intestine Large intestine The digestive tract and its accessory organs — schematic, not to scale.

Parts and helpers

Section titled “Parts and helpers”
  • Teeth — cut and grind food (mechanical digestion).
  • Tongue — moves and mixes food, and carries the sense of taste.
  • Salivary glands — release saliva, which moistens food and begins breaking down starch.

What it does

Section titled “What it does”
  • Ingestion — takes food in.
  • Mechanical digestion — chewing reduces food to a swallowable mass.
  • Chemical digestion — salivary enzymes start on starch.

Key idea

Section titled “Key idea”

The mouth turns food into a soft, lubricated bolus and starts the chemical work — and it is the only stage of digestion fully under voluntary control.