medulla renis的用法和樣例：
例句
- Countercurrent exchange in the vasa recta preserves hyperosmolarity of the renal medulla.
保持腎髓質的高滲作用，並將水，包括集合管和髓袢降支重吸收的水帶走。 - This rare renal tumor shows differentiation towards medullary collecting tubules.It is usually centered on the medulla with extension towards the cortex.
腎集合管癌較少見，主要發生於腎髓質內，病變可向腎皮質擴展。
