The abdominopelvic cavity is lined with a serous membrane called the peritoneum. This membrane expands from the internal surface of the abdominal wall to completely or partially surround organs of the abdominopelvic cavities.
The peritoneum is a serous membrane that consists of two layers: parietal peritoneum and visceral peritoneum (Figure 8-1A–C). The parietal peritoneum lines the internal walls of the abdominal cavity, forming a closed sac known as the peritoneal cavity. The peritoneal cavity is completely closed in males. In females, the peritoneal cavity has two openings where the uterine tubes, uterus, and vagina provide a passage to the outside. The parietal peritoneum reflects off of the posterior abdominal wall, forming a fused, double layer of peritoneum surrounding the blood vessels, nerves, and lymphatics to abdominal organs. This double layer of peritoneum, known as the mesentery, suspends the jejunum and ileum from the posterior abdominal wall. The peritoneum that surrounds the gut tube is called the visceral peritoneum. The peritoneal membranes produce a serous fluid that lubricates the peritoneal surfaces, enabling the intraperitoneal organs to slide across one another with minimal friction.
A. Sagittal section of the peritoneum and mesentery. B. Relationship of the mesentery and neurovascular supply to the intraperitoneal organs. C. Axial (cross-section) of the peritoneum and mesentery.
The omentum refers to modified mesenteries associated with the stomach and liver (Figure 8-1A).
- Greater omentum. An apron-like fold of mesentery that attaches between the transverse colon to the greater curvature of the stomach.
- Lesser omentum. Mesentery that attaches between the liver, stomach, and proximal portion of the duodenum. As a result, the lesser omentum is also referred to as the hepatogastric ligament and hepatoduodenal ligament. The lesser omentum forms a sac known as the omental bursa, which forms a subdivision of the peritoneal cavity known as the lesser sac. The greater sac is the remaining part of the peritoneal cavity. The greater and lesser sacs communicate with each other through the epiploic foramen (of Winslow).
Innervation and Vascular Supply of the Peritoneum
The neurovascular and lymphatic supply of the peritoneum course to and from the posterior abdominal wall and gut tube through the two-layered mesentery (Figure 8-1B). The vascular supply to the parietal peritoneum is through the same vessels that supply the abdominal body wall, mainly the intercostal, lumbar, and epigastric vessels. The vascular supply to the visceral peritoneum is through vessels that arise from the abdominal aorta. These vessels also supply the organs in the abdominal cavity.
The nerves supplying the parietal peritoneum are the same that supply the body wall (intercostal ...