are the kidneys in the peritoneal cavity
The viscera of the abdomen proper include the stomach, intestine, liver and biliary system, pancreas, spleen, kidneys, ureters, and suprarenal glands. Most of the stomach and intestine is anchored to the body wall by peritoneal mesentery, whereas the three paired glands (kidneys, suprarenals, and gonads before birth) lie retroperitoneally. The general relationships are shown in figures 26-1, 26-2, 26-3 and 26-4.