Cross-section illustration of organs in the abdomen at T12-L1. From left to right : the spleen, stomach, pancreas, kidney and the left adrenal gland, a vertebra, the abdominal aorta and the inferior vena cava, the right kidney and the liver. These are all surrounded by the diaphragm, the ribs and the intercostal muscles, the back muscles and the rectus abdominus muscle.