The renal papilla project into minor calyces which join together to form major calyces which funnel into the renal pelvis.

肾乳头突入肾小盏，每2-3个肾小盏合成肾大盏；2-3个肾大盏合并形成漏斗形的肾盂。

The medulla is made up of 10 to 18 renal pyramids with the base of the pyramids facing the renal cortex and the tips of the pyramids, called renal papilla—or nipples, pointing towards the center of the kidney.

髓质由10-18个肾锥体构成，每个锥体基底面朝向皮质；而尖端称作肾乳头，则朝向肾的中心。