What is digestion? Describe the process of digestion in humans with a diagram.
Show Hint
Digestion involves both mechanical processes (e.g., chewing) and chemical processes (e.g., enzymes breaking down food). A balanced diet supports efficient digestion.
Digestion is the process by which the food we eat is broken down into simpler forms such as sugars, fatty acids, and amino acids. This allows the nutrients to be absorbed into the bloodstream and transported to cells for energy, growth, and repair. The digestive system in humans is a complex series of organs working together to break down food. The process involves both mechanical and chemical digestion.
Process of Digestion in Humans:
1. Ingestion: The process starts when food enters the mouth. The teeth break down the food into smaller pieces (mechanical digestion), and saliva, which contains the enzyme amylase, begins breaking down starch (chemical digestion).
2. Mouth to Stomach: The food is then pushed down the esophagus to the stomach through a process called peristalsis (a wave-like muscle contraction).
3. Stomach: In the stomach, gastric juices containing hydrochloric acid and digestive enzymes break down proteins. The stomach churns food to mix it with digestive juices (mechanical digestion).
4. Small Intestine: The partially digested food moves into the small intestine, where most of the digestion and nutrient absorption occurs. The pancreas secretes enzymes that further break down food, while bile from the liver helps digest fats.
5. Absorption: Nutrients from the digested food are absorbed into the bloodstream through the villi (small finger-like projections) in the small intestine.
6. Large Intestine: Any remaining water and salts are absorbed in the large intestine, and the remaining waste is formed into stool.
7. Elimination: The waste is then excreted through the rectum and anus.
Conclusion:
Digestion is a vital process that begins in the mouth and ends with the elimination of waste. The small intestine is where most absorption takes place, while the large intestine focuses on absorbing water. The digestive system works harmoniously to break down food and absorb essential nutrients.
