What are renal pyramids and renal papillae ?

Renal pyramids : The medulla of the kidney is divided into multiple cone shaped masses of tissue called renal pyramids. The base of each pyramid originates at the   border between the cortex and the medulla and terminates in the renal papillae.
Renal papillae : The tips of the renal pyramids are called renal papillae. They project into cup like calyces.