The Digestive System and the role of Bile

What is the digestive system?

A group of organs that break down food from larger (insoluble into the bloodstream) molecules into smaller molecules which are absorbed into the bloodstream.

Role of Mouth?

Starts to break down carbohydrates

e.g amylase breaks down starch

Role of oesophagus

transports food from the mouth to the stomach

Role of Stomach

Starts to break down proteins

Role of duodenum

Continues digestion of proteins and carbohydrates and starts digestion of lipids.

Role of the Ileum

The Ileum completes digestion of proteins, carbohydrates and lipids and absorbs smaller molecules produced by them into the bloodstream

e.g amino acids, fatty acids, glycerol, glucose

Role of Large Intestine

Absorbs water and egests undigested food

Purpose of Bile

To Emulsify lipids (increases their surface area by breaking them down) in order to increase rate of enzyme action

To neutralise pH to make it close to the optimum of required enzymes

e.g lipase

Where is Bile made

The liver

Where is bile stored

the gallbladder

How is bile transported from the gall bladder to the small intestine

Via the bile duct