The suffix "ology" is added to the end of a stem and means "the study of." Urology is the name given to the surgical specialty that focuses on the urinary system of males and females, including the male reproductive system.
| Stem | Organ or Body Part That Stem Pertains To |
| Nephro/Rena | Kidney |
| Uretero | Ureter |
| Urethro | Urethra |
| Cysto | Bladder |
| Orchio | Testes |
| Uro and Uria | Urine |
| Lith | A stone |
