Are renal pelvis and calculi the same?

Renal pelvis and calculi are not the same.

Renal pelvis is the funnel-shaped upper portion of the ureter, which in turn is the tube connecting the kidney to the bladder. The renal pelvis is responsible for collecting urine from the kidney and sending it down to the ureter.

Calculi, also known as kidney stones, are hard, mineral deposits that can form in the kidneys or urinary tract. Calculi can be made up of different substances, including calcium, phosphate, or magnesium. They can vary in size from small grains of sand to large stones that can block the urinary tract.

Therefore, renal pelvis and calculi are different anatomical structures and substances.