Longitudinal section of kidney stained with hematoxylin/eosin and observed with the objective of 4x. We can observe the cortex and the medulla (we can distinguish in the last one an external and an internal zone).  The renal pyramid is also visible, whose end or papilla is surrounded by the calyx. Around the calyx are located the renal sine and the blood vessels. Details of the cortex and the pyramid appear at higher magnification in other microphotographies (zones framed in red, blue, and green)