1 - the CORTEX.
This layer is jam-packed with lots & lots of those Think of the cortex as the filtering layer of the kidney.

2 - the MEDULLA.
The middle layer. 
Tubes carrying filtered wastes travel from the cortex, through the medulla towards the pelvis.

3 - the PELVIS.
This is the area where all of the collecting tubules come together
& connect with the ureter  The ureter transports the wastes urine to the urinary bladder.