Digestion

Digestion is the process of breaking down food into smaller components that can be absorbed and used by the body. It involves both mechanical and chemical processes that occur in the digestive system.

Mechanical Digestion

Mechanical digestion involves the physical breakdown of food into smaller pieces. This process begins in the mouth with chewing and continues in the stomach through churning and mixing of food with digestive enzymes and acids.

Chemical Digestion

Chemical digestion involves the breakdown of large molecules into smaller molecules by enzymes. This process begins in the mouth with the action of salivary amylase on carbohydrates, and continues in the stomach and small intestine with the action of various enzymes on proteins, fats, and carbohydrates.

The Digestive System

The digestive system is composed of the mouth, esophagus, stomach, small intestine, large intestine, and various accessory organs such as the liver, pancreas, and gallbladder. Each of these organs plays a specific role in the digestion and absorption of nutrients.

Processes of Digestion

The process of digestion involves several key steps:

• Ingestion: Taking food into the mouth
• Propulsion: Movement of food through the digestive tract, including swallowing and peristalsis
• Digestion: Mechanical and chemical breakdown of food
• Absorption: Uptake of nutrients by the cells of the digestive tract
• Elimination: Removal of undigested and unabsorbed materials from the body

Study Guide

To effectively study digestion, it is important to focus on the following key points:

1. Understand the difference between mechanical and chemical digestion and provide examples of each.
2. Memorize the organs of the digestive system and their specific functions.
3. Be able to explain the processes of ingestion, propulsion, digestion, absorption, and elimination in detail.
4. Study the role of enzymes in chemical digestion and how they facilitate the breakdown of different types of nutrients.
5. Understand the importance of a balanced diet in providing the necessary nutrients for the body's functions.