Which organ is NOT present in the right upper quadrant of the abdomen?

The descending colon is primarily located in the left side of the abdomen, specifically in the left upper quadrant and lower left quadrant, making it the organ that does not belong in the right upper quadrant. The right upper quadrant typically contains the gallbladder, which is responsible for bile storage; the duodenum, which is the first part of the small intestine and plays a crucial role in digestion; and the right kidney, which is part of the urinary system and helps in filtering blood and producing urine. Understanding the anatomical organization of the abdominal cavity highlights the location of various organs, emphasizing that certain organs have specific quadrant associations based on their typical position within the body.