Definition: Digestion and Digestive system

Every cell in the human body requires a steady stream of nutrients to give energy and the raw materials needed to create bodily compounds. The alimentary canal, auxiliary organs, and digestive processes are all referred to as the digestive system collectively. The major job of the digestive system is to get food ready for blood or lymph absorption so that the body's cells can use it. There are four primary activities that the digestive system engages in:

• Ingestion: Eating and drinking both entail putting food and liquid into the mouth.
• Large molecules are broken down into smaller molecules during digestion, preparing them for absorption. Chemical and mechanical digestion are both involved in digestion.
• Before food is swallowed, the teeth cut and grind it, and then the stomach and small intestine's smooth muscles churn it. Food molecules dissolve as a result, mixing with digestive enzymes.
• Food components such as fat, protein, nucleic acid, and carbohydrates are broken down into simpler forms during chemical digestion. Salivary gland, stomach, pancreas, and small intestine create digestive enzymes. Only a small number of substances in food, including vitamins, ions, cholesterol, and water, can be absorbed without the chemical digestion process of nutrient absorption.
• Absorption: The process of absorption is the ingestion of nutritional molecules, which occurs first in the epithelial cells of the gastrointestinal tract, followed by the blood and lymph, and eventually cells all over the body.
• Defecation, also known as elimination, is the process by which fluids, indigestible materials, bacteria, cells sheared from the GI tract lining, and residue are expelled through the digestive tract. Feces are the name for the excreted material.

Functions of the Digestive System

• It facilitates food intake through the mouth.
• It aids in the release of buffers, enzymes, and other substances into the GI tract's lumen.
• It facilitates food mixing, churning, and passage through the GI tract.
• It aids in the food's chemical and mechanical digestion.
• It facilitates the transfer of nutrients and products of digestion from the GI tract to the blood and lymph.
• It aids in the body's excretion of harmful and useless wastes such as feces.