True about ascending limb of loop of Henle ?
**Core Concept**
The ascending limb of the loop of Henle is a critical structure in the renal medulla responsible for electrolyte and water reabsorption. It is divided into two parts: the thick ascending limb (TAL) and the thin ascending limb (TAL). The TAL is the primary site of magnesium and calcium reabsorption, while the TAL is involved in potassium reabsorption.
**Why the Correct Answer is Right**
The thick ascending limb is characterized by the presence of the Na-K-2Cl cotransporter (NKCC2), which is responsible for the reabsorption of sodium, potassium, and chloride ions. This process is driven by the energy generated from the hydrolysis of ATP. The correct answer is related to the function of this transporter. The thick ascending limb is also the site where the countercurrent multiplier system is established, allowing for the concentration of the urine.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the primary function of the ascending limb of the loop of Henle.
**Option B:** This option is incorrect because it is not a characteristic of the ascending limb of the loop of Henle.
**Option C:** This option is incorrect because it is not a specific function of the ascending limb of the loop of Henle.
**Clinical Pearl / High-Yield Fact**
The loop diuretics, such as furosemide, act by inhibiting the Na-K-2Cl cotransporter in the thick ascending limb, leading to increased excretion of sodium, chloride, and potassium ions.
**Correct Answer:** C.