What physiological substance is indicated by the combining form ur/o?

The combining form ur/o specifically refers to urine or anything related to the urinary system. This prefix derives from the Greek word "ouron," which means "urine." It is commonly used in medical terminology to describe conditions, procedures, or organs associated with urine.

For example, words like "urology" (the branch of medicine that focuses on urinary tract disorders) and "urethra" (the duct through which urine is discharged) both incorporate this combining form. Understanding these roots is crucial for deciphering medical terminology related to the urinary system.