The renal tubule is the portion of the nephron containing the tubular fluid
Tubular fluid
Tubular fluid is the fluid in the tubules of the kidney. It starts as a renal ultrafiltrate in the glomerulus, changes composition through the nephron, and ends up as urine leaving through the ureters.-Composition table:...

 filtered through the glomerulus. After passing through the renal tubule, the filtrate continues to the collecting duct system
Collecting duct system
The collecting duct system of the kidney consists of a series of tubules and ducts that connect the nephrons to the ureter. It participates in electrolyte and fluid balance through reabsorption and excretion, processes regulated by the hormones aldosterone and antidiuretic hormone.There are several...

, which is not part of the nephron.

The components of the renal tubule are:
  • Proximal convoluted tubule (lies in cortex and lined by simple cuboidal epithelium with brushed borders which help to increase the area of absorption greatly.)
  • Loop of Henle
    Loop of Henle
    In the kidney, the loop of Henle is the portion of a nephron that leads from the proximal convoluted tubule to the distal convoluted tubule. Named after its discoverer F. G. J...

     (hair-pin like i.e.