Digestive System Overview Quiz

Digestive System Overview

• The digestive system performs four main functions: ingestion, digestion, absorption, and elimination.
• Ingestion: Food enters the mouth.
• Digestion: Food is broken down mechanically (e.g., chewing) and chemically (e.g., by enzymes).
• Absorption: Nutrients are taken into the bloodstream.
• Elimination: Solid waste is removed from the body.

Ingestion and Mechanical Digestion

• Food enters the mouth.
• The tongue, teeth, and saliva break down food.
• Food moves to the esophagus.
• Mechanical digestion involves physically breaking down food, like chewing.

Chemical Digestion and Stomach

• Food is digested in the stomach (muscular contractions, hydrochloric acid).
• Chemical digestion breaks food molecules into smaller ones.

Small Intestine and Absorption

• Digestion continues in the small intestine.
• Nutrients are absorbed into the bloodstream.
• The small intestine has specialized structures (villi) to increase absorption surface area.

Large Intestine and Elimination

• Undigested food moves to the large intestine.
• Water and some nutrients are reabsorbed.
• Undigested material becomes feces.
• Feces are stored in the rectum and eliminated through the anus.

Peristalsis

• Peristalsis is a wave-like muscle movement that pushes food along the digestive tract.
• It moves in one direction.
• Reverse peristalsis occurs during vomiting.

Small Intestine Structure

• The small intestine is made up of multiple layers:
  • Mucosa (epithelial tissue)
  • Submucosa (connective tissue)
  • Circular muscle fibers
  • Longitudinal muscle fibers
  • Serosa (connective tissue)
  • Villi (epithelial tissue)
• Goblet cells secrete mucus to protect the lining.

Digestive System Function Summary

• The main function of the digestive system is to break down food, absorb nutrients, and dispose of waste.