Digestive System Overview

Introduction

• Everyone experiences digestive system issues, ranging from mild to severe.
• Understanding the journey of food through the digestive system.

Digestive System as a Long Tube

• Esophagus: First part of the tube.
• Stomach: Transitions from the esophagus.
• Small Intestine: Longest part, length varies (16-29 feet).
• Large Intestine: Shorter but wider than the small intestine.

Ingestion

• Mouth: Start of digestion.
  • Mechanical digestion: Chewing.
  • Chemical digestion: Saliva from salivary glands (parotid, submandibular, sublingual).
• Pharynx: Throat area.

Esophagus

• Function: Transports food from pharynx to stomach.
• Experiences heartburn due to acid reflux.

Stomach

• Produces hydrochloric acid.
• Churns food, located in the upper left quadrant.
• Features gastric rugae (folds) for expansion during large meals.

Small Intestine

• Divided into three segments: Duodenum, Jejunum, Ileum.
  • Duodenum: Initial digestion with help from accessory organs.
    • Liver: Produces bile.
    • Gallbladder: Stores bile.
    • Pancreas: Produces digestive enzymes.
  • Jejunum & Ileum: Main site for nutrient absorption.

Large Intestine

• Begins with the Cecum.
• Transition from Ileum to Cecum via ileocecal valve.
• Segments:
  • Ascending Colon
  • Transverse Colon
  • Descending Colon
  • Sigmoid Colon connects to the rectum and anus.
• Functions: Stores fecal matter, absorbs water and salts.

Additional Structures

• Appendix: Small, worm-like structure off the cecum.
• Circular Folds: In small intestine, increase nutrient absorption.

Conclusion

• Digestive system is crucial for nutrient absorption and waste elimination.
• Encouragement for further learning and exploration on the topic.