ABSTRACT
The kidneys of the rat are still developing at birth, and the number of glomeruli increases until 100 days. The final number of nephrons is strain dependant and varies between 20 000 and 40 000 (Arataki, 1926). The rat kidney is unilobular (i.e. it has a single pyramid), unlike the human kidney which has 10-14 lobules. The cortex forms a cap over the medulla and the tip (papilla) projects into the renal sinus.
