Final answer:
Major calyces in the renal system are large branches of the renal pelvis that collect urine from the nephrons.
Step-by-step explanation:
In the renal system, the major calyces are large branches of the renal pelvis. They are extensions of the renal pelvis and are responsible for collecting urine produced by the nephrons in the kidney. The major calyces further branch into smaller structures called minor calyces, which then connect to the renal papillae.