What are the tubes called inside kidneys?

The tubes inside the kidneys are called nephrons. Each kidney contains millions of nephrons, which are the functional units of the kidneys. Each nephron consists of a renal corpuscle (which includes the glomerulus and Bowman's capsule) and a renal tubule. The renal tubule is a long, coiled tube that leads from the renal corpuscle to the collecting duct. The collecting ducts collect urine from the nephrons and carry it to the renal pelvis, which is the central cavity of the kidney.