Gastrointestinal (GI) Tract Overview

GI Tract Components

• Stomach
• Small Intestines
• Large Intestines

Stomach Regions and Structures

• Cardia
  • Adjacent to esophagus entrance
  • Contains cardia glands
• Fundus
  • Dome-shaped, gas accumulates here
• Body
  • Main portion with lesser and greater curvatures
• Gastric Rugae
  • Internal ridges allowing expansion
• Pylorus
  • Terminal part with pyloric sphincter
• Omenta
  • Lesser Omentum: Connects lesser curvature to liver, includes hepatoduodenal and hepatogastric ligaments
  • Greater Omentum: Arises from greater curvature, covers abdominal viscera, contains lymph nodes

Small Intestines

• Components: Duodenum, Jejunum, Ileum
• Duodenum
  • Four parts: Superior, Descending, Transverse, Ascending
  • First Part: Duodenal cap, smooth wall, site for ulcers
  • Second Part: Bile and pancreatic ducts enter
  • Third Part: Transverse, superior mesenteric artery and vein
  • Fourth Part: Ascending, ligament of Treitz
• Jejunum
  • Upper left quadrant, numerous circular folds
• Ileum
  • Lower right quadrant, fewer folds, Peyer's patches

Large Intestines

• Components: Cecum, Ascending/Transverse/Descending Colon, Sigmoid Colon, Rectum, Anus
• Cecum
  • Receives ileum contents, has appendix
  • McBurney's point for surface anatomy
• Ascending Colon
  • Ends at hepatic flexure
• Transverse Colon
  • Between hepatic and splenic flexures
• Descending Colon
  • Ends at lower left quadrant
• Sigmoid Colon
  • S-shaped, leads to rectum
• Rectum and Anus
  • Straight path to anus
  • Internal (involuntary) and external (voluntary) sphincters

Anatomy and Function Highlights

• GI tract facilitates digestion and absorption of nutrients.
• Stomach regions have distinct functions and structures aiding digestion.
• Small intestines are the primary site for nutrient absorption.
• Large intestines handle absorption of water and electrolytes, formation of feces.