Which organ is primarily responsible for digestion?

The stomach plays a crucial role in the digestion process by acting as a reservoir where food is mixed with gastric juices. These juices contain hydrochloric acid and digestive enzymes, which help break down proteins and sterilize the food by killing harmful bacteria. The muscular walls of the stomach contract to churn the food and facilitate this mixing, turning it into a semi-liquid substance known as chyme.

While the small intestine is where the majority of nutrient absorption occurs, the stomach is vital for the initial phase of digestion, where food is broken down into a form that can be processed further. The liver and large intestine also contribute to the digestive process — the liver produces bile essential for fat digestion, and the large intestine is involved in the absorption of water and formation of waste — but the primary mechanical and chemical digestion occurs in the stomach. This distinction makes it clearer why the stomach is often considered the primary organ in the digestion process.