The digestive system or the excretory system.
the kidney belongs to the osmo-regulation and the excreatory system.
the urinary system
The urinary system
The digestive system or the excretory system.
the digestive system
Kidney and baldder
Yes the kidney is the main organ in the urinary system as well as the bladder.
The renal system.
It is part of the genitourinary system
the digestive system
The circulatory system brings nutrients to the kidney. It also removes metabolic wastes from the tissues of the kidney.
Not usually because the kidney is not part of the reproductive system, but keep in mind that whatever caused the loss of the kidney in the first place may have had an effect on the reproductive system.