Human Digestive System

Digestive System

Overview

• The digestive system is a complex process by which the body breaks down and absorbs nutrients from food.
• It consists of the alimentary canal (mouth, esophagus, stomach, small intestine, and large intestine) and accessory organs (liver, pancreas, and gallbladder).

Functions

• Ingestion: mechanical breakdown of food in the mouth
• Digestion: chemical breakdown of food in the stomach and small intestine
• Absorption: uptake of nutrients into the bloodstream in the small intestine
• Elimination: removal of waste products from the body through the anus

Organs and Their Functions

• Mouth:
  • Mechanical breakdown of food by teeth
  • Saliva production for lubrication and enzymatic breakdown
• Esophagus:
  • Muscular tube that propels food to the stomach
• Stomach:
  • Mechanical churning and mixing of food with digestive enzymes
  • Acidic environment for protein denaturation
• Small Intestine:
  • Most absorption of nutrients occurs here
  • Villi and microvilli increase surface area for absorption
• Large Intestine:
  • Water and electrolyte absorption
  • Storage and elimination of feces
• Liver:
  • Production of bile for fat emulsification and absorption
  • Detoxification and metabolism of nutrients
• Pancreas:
  • Production of digestive enzymes for carbohydrate, protein, and fat breakdown
• Gallbladder:
  • Storage and release of bile into the small intestine

Digestive System

Overview

• The digestive system involves the breakdown and absorption of nutrients from food, comprising the alimentary canal and accessory organs.

Functions

• Ingestion involves mechanical breakdown of food in the mouth.
• Digestion is the chemical breakdown of food in the stomach and small intestine.
• Absorption occurs in the small intestine, where nutrients are taken up into the bloodstream.
• Elimination is the removal of waste products from the body through the anus.

Organs and Their Functions

Mouth

• Teeth facilitate mechanical breakdown of food.
• Saliva production aids in lubrication and enzymatic breakdown.

Esophagus

• This muscular tube propels food to the stomach.

Stomach

• Food is mixed with digestive enzymes and undergoes mechanical churning.
• The stomach's acidic environment facilitates protein denaturation.

Small Intestine

• Most nutrient absorption occurs in the small intestine.
• Villi and microvilli increase the surface area for absorption.

Large Intestine

• Water and electrolyte absorption occur in the large intestine.
• This organ stores and eliminates feces.

Liver

• The liver produces bile for fat emulsification and absorption.
• It also performs detoxification and metabolism of nutrients.

Pancreas

• The pancreas produces digestive enzymes for carbohydrate, protein, and fat breakdown.

Gallbladder

• The gallbladder stores and releases bile into the small intestine.