Sistema Digestivo Humano: Trato Completo com Digestão Mecânica e Química

The human digestive system is a complete (tube-within-tube) gastrointestinal tract with two openings (mouth, anus) and specialized regions for mechanical and chemical processing.

Organs and Functions

1. Mouth: Mastication (mechanical), salivary amylase (chemical).
2. Pharynx/Esophagus: Transport via peristalsis.
3. Stomach: Churning (mechanical), HCl + pepsin (chemical protein denaturation).
4. Small Intestine: Segmentation/peristalsis (mechanical); pancreatic enzymes, bile, brush-border enzymes (chemical); nutrient absorption.
5. Large Intestine: Water/electrolyte absorption; microbial fermentation (chemical); stool formation.
6. Rectum/Anus: Storage and defecation reflex.

Accessory Organs

• Salivary glands, liver, gallbladder, pancreas — secrete into lumen via ducts.

Regulation

Enteric nervous system (ENS), hormones (gastrin, CCK, secretin, GIP), vagovagal reflexes coordinate secretion and motility.

Complete digestion enables efficient nutrient extraction and waste elimination.