What are the six main processes of the digestive system?

Verified step by step guidance

1. Ingestion: This is the process of taking in food through the mouth. It involves the mechanical breakdown of food by chewing and the chemical breakdown by saliva.
2. Propulsion: This involves the movement of food through the digestive tract, which includes swallowing and peristalsis, a series of wave-like muscle contractions that move food along the digestive tract.
3. Mechanical Digestion: This process physically breaks down food into smaller pieces. It includes chewing in the mouth and churning in the stomach.
4. Chemical Digestion: This involves breaking down food into simpler nutrients that can be absorbed. Enzymes and acids play a crucial role in this process, breaking down carbohydrates, proteins, and fats.
5. Absorption: This is the process by which nutrients from digested food are absorbed into the bloodstream through the walls of the intestines.
6. Defecation: This is the elimination of indigestible substances and waste products from the body in the form of feces.

Key Concepts

Ingestion

Ingestion is the first process of the digestive system, involving the intake of food and liquids into the mouth. This process is crucial as it marks the beginning of digestion, where food is mechanically broken down by chewing and mixed with saliva, which contains enzymes that initiate the breakdown of carbohydrates.

Digestion

Digestion refers to the chemical and mechanical breakdown of food into smaller, absorbable components. This process occurs in two stages: mechanical digestion, which involves physical actions like chewing and churning in the stomach, and chemical digestion, where enzymes and acids break down food into nutrients that can be absorbed by the body.

Absorption

Absorption is the process by which the nutrients from digested food are taken up into the bloodstream or lymphatic system. This primarily occurs in the small intestine, where the surface area is maximized by villi and microvilli, allowing for efficient transfer of nutrients like amino acids, fatty acids, and sugars into the body for use.