The peritoneum stretches from the diaphragm to the pelvis and consists of the parietal peritoneum and the visceral peritoneum.
There is normally no empty space within the peritoneum. There is a tiny amount of peritoneal fluid normally but any accumulation of fluid (ascites) or gas (pneumoperitoneum) is abnormal. Inflammation of the peritoneum is peritonitis, which is usually caused by a perforation in the stomach or intestines and is a serious condition.
A listing of the major structures in the abdomen, divided into whether they are intraperitoneal or extraperitoneal.
Intraperitoneal structures
Extraperitoneal structures
Major blood vessels
adrenal glands
kidneys
ureters
bladder
/msg me for comments/suggestions/corrections (it's confusing enough figuring out from memory which structures belong where on this list)