The various parts labeled in the picture are:

1. Salivary gland
2. Pharynx
3. Epiglottis
4. Bolus
5. Liver
6. Pancreas
7. Gallbladder
8. Large intestine

The role of various organs in the digestion of food are indicated in text boxes on the right. These include:

1. Mouth: Teeth tear and grind food into small pieces. Enzymes in saliva kill some pathogens and start to break down carbohydrates. 1 minute.
2. Esophagus: Esophagus The bolus travels from the mouth to the stomach via the esophagus. Food is squeezed through by peristalsis. 2–3 seconds.
3. Stomach: Stomach Muscle contractions produce a churning motion that breaks up food and forms a liquid mixture called chyme. Protein digestion begins. 2–4 hours.
4. Small intestine: Chyme is slowly released into the small intestine. Bile, which is made in the liver, is released from the gallbladder into the small intestine and aids in fat digestion. Enzymes from the pancreas and duodenum complete digestion. Nutrients are absorbed through the small intestine wall. 3–5 hours.
5. Large intestine: The large intestine absorbs water as undigested material moves through and is eliminated from the body. 10 hours–several days.

An enlarged photograph of cardiac sphincter is displayed on the left above the liver in the picture. The text box above this reads ‘The cardiac sphincter closes after food passes into the stomach.’ A micrograph of glands in the stomach lining is displayed on the bottom left of the picture. The text box below this reads ‘Glands in the stomach lining release hydrochloric acid, pepsin, and mucus.’