What are the muscular tubes that transport urine from the kidneys to the bladder called?

The muscular tubes that transport urine from the kidneys to the bladder are known as ureters. These tubes play a crucial role in the urinary system, as they facilitate the movement of urine, which is produced in the kidneys, down to the bladder for storage before it is excreted from the body. The ureters are lined with smooth muscle, which contracts rhythmically to help propel the urine through gravity and peristaltic movements.

Other structures mentioned in the options serve different functions within the urinary system. The urethra is the duct through which urine is expelled from the bladder to the outside of the body. Renal arteries are responsible for supplying blood to the kidneys, while nephrons are the functional units within the kidneys that filter blood and produce urine. Understanding these distinctions highlights the specific role of ureters in the urinary tract.