Question

Draw a labelled diagram of the human digestive system and explain the digestive process.

Hint:

The digestive system works through a combination of mechanical breakdown, enzymatic digestion, absorption of nutrients, and elimination of waste.

Answer 1

The human digestive system is responsible for breaking down food into simpler molecules that can be absorbed by the body. The main parts of the digestive system are:
1. Mouth:
Digestion begins in the mouth, where food is mechanically broken down by chewing and chemically broken down by saliva, which contains enzymes like amylase that start carbohydrate digestion.
2. Esophagus:
The food is swallowed and travels down the esophagus through peristalsis (wave-like muscle contractions) to reach the stomach.
3. Stomach:
In the stomach, food is mixed with gastric juices, which contain hydrochloric acid and pepsin (an enzyme that starts protein digestion). The stomach churns the food into a semi-liquid substance called chyme.
4. Small Intestine:
The chyme enters the small intestine, where most digestion and absorption occur. The pancreas releases enzymes (amylase, lipase, protease) that break down carbohydrates, fats, and proteins. The liver produces bile, which emulsifies fats, aiding in their digestion. The walls of the small intestine absorb nutrients into the bloodstream.
5. Large Intestine:
Any remaining indigestible food passes into the large intestine, where water is absorbed, and the remaining material is compacted into feces.
6. Anus:
Finally, the feces are expelled from the body through the anus during defecation.
Digestive Process:
1. Ingestion: Food is taken into the mouth.
2. Digestion: Food is mechanically and chemically broken down into smaller molecules.
3.Absorption: Nutrients from the digested food are absorbed into the bloodstream through the walls of the small intestine.
4. Elimination: Indigestible food materials are eliminated from the body as feces.
Conclusion:
The digestive system processes food, absorbs nutrients, and removes waste, playing a crucial role in maintaining overall health.