The stomach

• The bolus enters the stomach through the cardiac sphincter
• There are 3 layers of muscle in the stomach
• The contraction of muscles act to break down food mechanically
• The main function of the stomach is protein digestion
• Gastric protease (pepsin) is the enzyme which is secreted by glands help in long tubes called gastric pits which line the stomach
• These gastric glands also secrete hydrochloric acid which also helps to chemically break down food
• The stomach has a thick lining of mucous to protect itself from the acids and enzymes
• Food remains in the stomach for between 2-8 hours before being pushed by the peristalsis to the small intestine