Left upper quadrant organs:
Stomach, spleen and part of the pancreas (posterior)
Right upper quadrant organs:
Liver, gallbladder, and duodenum of the intestines, and part of the pancreas
Left lower quadrant organs:
Large and small bowel (descending colon, and left half of the transverse colon)
Right lower quadrant organs:
Portion of the large and small intestine (ascending colon and right half of the transverse colon), appendix