Final answer:
The incorrect statement about the kidneys is that the left kidney lies behind the liver, and the right kidney lies behind the spleen. In fact, these positions are reversed as the right kidney is located behind the liver and the left kidney behind the spleen.
Step-by-step explanation:
The statement that is not true regarding the kidneys is: "The left kidney lies behind the liver, and the right kidney lies behind the spleen." In reality, the right kidney is located behind the liver, and the left kidney is positioned behind the spleen. The kidneys are a pair of bean-shaped organs that are located on either side of the spine, just below the diaphragm, in the retroperitoneal space. Each kidney houses approximately one million nephrons, which are the microscopic structures responsible for filtering blood and producing urine. A healthy kidney in a young adult indeed is about the size of a fist.