Final answer:
The peritoneum is a double-layer serous membrane that includes the parietal peritoneum lining the walls of the abdominopelvic cavity and the visceral peritoneum surrounding the organs. The serous space between these layers reduces friction, aiding in organ protection.
Step-by-step explanation:
The peritoneum is a double-layer serous membrane. One layer, known as the parietal peritoneum, lines the walls of the abdominopelvic cavity. Conversely, the visceral peritoneum surrounds each of the organs within this cavity. These two layers are separated by a serous space filled with fluid, which acts as a lubricant to minimize friction and allows smooth movement of the organs.
The peritoneal cavity is the specific space bounded by the visceral and parietal peritoneal surfaces. This cavity, along with the pleural cavity for the lungs and the pericardial cavity for the heart, constitutes one of the three serous cavities in the human body. These cavities and their embedded membranes play a crucial role in protecting internal organs by reducing friction and potential inflammation during organ movement.