The Digestive System: Breaking Down Food, Step by Step

The digestive system is like a factory, breaking food into tiny pieces so your body can use it for energy, growth, and repair.

 

What is the Digestive System?

The digestive system is a group of organs that work together to:

1. Ingest (take in food).
2. Digest (break down food into smaller pieces).
3. Absorb (move nutrients into the blood).
4. Assimilate (use nutrients in cells).
5. Egest (remove undigested food as waste).

 

 

The Main Parts of the Digestive System

The digestive system has two key parts:

Alimentary Canal: The long tube food passes through.

Associated Organs: Help with digestion but food doesn’t pass through them.

 

1. Alimentary Canal

Organ	Function
Mouth	Chews food into smaller pieces (mechanical digestion) and mixes it with saliva (chemical digestion).
Oesophagus	Moves food from the mouth to the stomach using peristalsis (wave-like muscle contractions).
Stomach	Churns food (mechanical digestion) and mixes it with gastric juices, which contain enzymes and acid.
Small Intestine	Duodenum: Enzymes and bile break down food further.

 

2. Associated Organs

Organ	Function
Salivary Glands	Produce saliva, which contains the enzyme amylase to break down starch into sugar.
Liver	Produces bile, which helps break down fats.
Gall Bladder	Stores bile and releases it into the small intestine when needed.
Pancreas	Produces enzymes like lipase, protease, and amylase, which are released into the small intestine.

 

Key Processes in the Digestive System

Ingestion

• Taking in food and drink.
• Example: Eating a sandwich.

Digestion

• Breaking food into smaller pieces so the body can use it.
• Mechanical Digestion: Chewing, churning in the stomach.
• Chemical Digestion: Enzymes breaking down food molecules.

Absorption

• Moving nutrients (like glucose, amino acids) from the small intestine into the blood.

Assimilation

• Cells using absorbed nutrients to grow, repair, and produce energy.

Egestion

• Removing undigested food as faeces through the anus.