what is the difference between fundamental quantities from derived quantities? Nature itself doesn't have fundamental or derived quantities. We have choices of units with more or less direct ties to things we measure. In modern systems of units, we try to simplify things by making units for different quantities have simple relations.
The left lower quadrant (LLQ) contains the distal descending colon, the sigmoid colon and the left ureter. Depending on the sex of the individual, both the left and right lower quadrants contain either an ovary, a uterine tube, a ductus deferens, the uterus and the urinary bladder.
The liver and gall bladder are located in the upper right quadrant and could be the cause, but also pain can be referred from other organs like the lung and heart or intestine. You need to see your doctor right away to be examined to determine the cause of the pain and get proper treatment.