Doctors can often see a large hiatus hernia on a chest x-ray. Otherwise, people are given barium in a liquid before x-rays are taken (barium swallow). The barium outlines the esophagus, making abnormalities easier to see. Hernias can also be seen during an upper endoscopy.
The kidneys filter the blood to remove wastes and produce urine. The ureters, urinary bladder, and urethra together form the urinary tract, which acts as a plumbing system to drain urine from the kidneys, store it, and then release it during urination.
Excretion and the liver Excretion in mammals Excretion is the removal of potentially harmful or toxic substances from the body. These substances are usually waste materials produced by complex chemical reactions taking place in living cells.