Kidneys and Urinary Tract

How the kidneys work: https://www.niddk.nih.gov/health-information/kidney-disease/kidneys-how-they-work

Functions of the urinary tract: https://www.urologyhealth.org/urologic-conditions/urinary-tract-problems

Kidney and urinary tract diseases: https://www.kidney.org/atoz/content/kidneydiscauses