Churning in the stomach

The idea

The stomach walls churn food with a secretion of digestive juice that breaks down proteins, acid that helps break proteins and kills many harmful bacteria, and mucus that protects the lining from the acid.

Inside the stomach

The stomach has strong walls, and it holds acid.

What protects the stomach lining from its own acid?

• A layer of mucus
• Nothing, the acid is harmless
• The food eats the acid

Churn it

Press Churn. Then tap Juice, Acid and Mucus.

Three secretions

The stomach walls churn the food and mix it with a secretion from the stomach lining. The secretion has digestive juice, acid and mucus, and each one has its own job.

The stomach walls churn food with a secretion of digestive juice that breaks down proteins, acid that helps break proteins and kills many harmful bacteria, and mucus that protects the lining from the acid.

• Secretion | Job
• Digestive juice | Breaks down proteins
• Acid | Helps break proteins, kills many harmful bacteria
• Mucus | Protects the lining from the acid

Notes

The stomach walls churn food with a secretion of digestive juice that breaks down proteins, acid that helps break proteins and kills many harmful bacteria, and mucus that protects the lining from the acid.

Check yourself

What does the digestive juice of the stomach break down?

What does the mucus do?

Which secretion kills many harmful bacteria?

What do the stomach walls do to the food?

• Proteins — correct. Yes!
• Water. Water is already simple. The stomach juice breaks down proteins.
• Only starch. Starch digestion starts in the mouth. In the stomach the juice breaks down proteins.
• Makes more acid. Mucus does not make acid. It protects the lining from the acid.
• Protects the stomach lining from the acid — correct. Yes!
• Kills harmful bacteria. Killing many harmful bacteria is the job of the acid, not of the mucus.
• The mucus. Mucus protects the lining. The acid kills many harmful bacteria.
• The bile. Bile is made by the liver. The stomach acid kills many harmful bacteria.
• The acid — correct. Yes!
• Churn it — correct. Yes!
• Freeze it. The walls do not freeze food. They churn it by contracting and relaxing.
• Stretch it into a thread. The walls churn the food and mix it with the secretion of the lining.