Yes the kidney is the main organ in the urinary system as well as the bladder.
No, a nephron is not an organ. It is the basic structural and functional unit of the kidney and filters excess salt and water from the blood. The kidney is the main organ of the urinary system. Without a kidney, your body cannot create urine and you blood must be filtered with a dialysis machine.
The main organ in the excretory system is the kidney. The kidney is the main organ that controls the excretory systems for vertebrates. It is also part of the Urinary system which is part of the excretory system.
The main organ of the urinary system is kidneys. (The ureters seems to be least important. Till kidney stone enters these tubes. Then you forget every thing and demand the relief from the pain. The kidneys will be damaged due to over dilatation if the tubes are blocked for long time.)
The main organ of the excretory system is the kidneys. The kidneys filter waste products and excess substances from the blood to produce urine, which is then eliminated from the body through the urinary system.
Kidneys
Both kidneys and the liver, along with many lymph nodes.
Kidneys - Urinary System
I don't know that they're the main organs, but kidneys are certainly essential to the urinary system.
The main organ of the urinary system is the kidney. It filters blood to remove waste products and regulate fluid balance, producing urine that is then excreted from the body through the urinary tract.
The kidney is the primary organ of the excretory system. The ureter is simply a tube that carries urine from one place to another which, while important, does not carry out the main process of the urinary/excretory system. (creating urine)
the main organ of the muscular system is the muscles
the kidney's.