Anatomy of the Peritoneum

Introduction

• The peritoneum is a serous membrane lining the inside of the abdominal wall and surrounding organs in the abdominal cavity.
• It provides protection, fixes organs in place, and creates a smooth environment.

Parts of the Peritoneum

Parietal Peritoneum

• Lines the internal surface of the abdominal and pelvic walls.
• Wraps around anterior, lateral, and posterior abdominal walls.

Visceral Peritoneum

• Lines the walls of the organs, forming a serous coat.
• Produces serous fluid with the parietal peritoneum filling the peritoneal cavity.

Peritoneal Cavity

• The space between the visceral and parietal peritoneum.
• Contains serous fluid.

Types of Organ Coverage by Visceral Peritoneum

Intraperitoneal Viscera

• Organs completely covered by visceral peritoneum.
• Includes: stomach, spleen, cecum, appendix, transverse colon, sigmoid colon, upper rectum, jejunum, ileum.

Mesoperitoneal Organs

• Partially covered by visceral peritoneum.
• Includes: liver, gallbladder, ascending/descending colon, middle rectum, urinary bladder (when full).

Retroperitoneal Organs

• Covered by visceral peritoneum on one side.
• Includes: duodenum, pancreas, kidneys, suprarenal glands, ureter, urinary bladder (when empty).

Ligaments and Omenta

Parietal to Visceral Peritoneum Transition

• Occurs via four ligaments.
• Important ligaments:
  • Falciform Ligament: connects liver to anterior abdominal wall.
  • Coronary Ligament: connects liver to diaphragm.
  • Right & Left Triangular Ligaments.

Lesser Omentum

• Formed under the liver, above the stomach.
• Consists of:
  • Hepatogastric Ligament: connects liver to the stomach.
  • Hepatoduodenal Ligament: connects liver to the duodenum.

Greater Omentum

• Extends from greater curvature of the stomach.
• Includes:
  • Gastrocolic Ligament.
  • Gastrosplenic Ligament.
  • Gastrofranic Ligament.

Mesentery

• Connects intestines to the posterior abdominal wall.
• Provides structural support and a pathway for vascular supply.
• Types:
  • Transverse Mesocolon: connects transverse colon.
  • Related to small intestine and sigmoid colon.

Levels of the Peritoneal Cavity

Upper Level

• Above the transverse mesocolon.
• Contains subphrenic and subhepatic recesses and the omental bursa (lesser sac).

Middle Level

• Below transverse mesocolon, above terminal line of pelvis.
• Contains diverse recesses located around duodenum and cecum.

Lower Level

• Below terminal line, within the lesser pelvis.
• Female-specific pouches:
  • Recto-uterine pouch.
  • Vesicouterine pouch.
• Male-specific pouch:
  • Recto-vesical pouch.

Conclusion

• The peritoneum plays a critical role in the abdominal cavity structure and function.
• Understanding of peritoneal space and structures is essential for medical knowledge.