The neotatal kidney achieves concertratiug ability equivalent to adult’s kidney by –
**Core Concept**
The neonatal kidney undergoes significant changes in the first few weeks of life, gradually acquiring the concentrating ability of the adult kidney. This process is crucial for the proper development of the renal system and overall health of the newborn.
**Why the Correct Answer is Right**
The concentrating ability of the neonatal kidney is achieved through the maturation of the renal concentrating mechanism, which involves the development of the renal medulla and the thick ascending limb of the loop of Henle. As the kidney matures, the expression of aquaporin-2 water channels in the collecting duct increases, allowing for more efficient water reabsorption and concentration of urine. Additionally, the maturation of the renin-angiotensin-aldosterone system (RAAS) also plays a crucial role in regulating electrolyte and water balance, ultimately contributing to the concentrating ability of the kidney.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify a mechanism or timeframe for the development of concentrating ability in the neonatal kidney.
**Option B:** This option is incorrect because it is too vague and does not provide any information about the specific changes that occur in the kidney to achieve concentrating ability.
**Option C:** This option is incorrect because it implies that the neonatal kidney never achieves concentrating ability, which is not true.
**Clinical Pearl / High-Yield Fact**
The concentrating ability of the neonatal kidney is not fully developed until around 3-6 months of age, which is an important consideration for pediatricians when managing fluid and electrolyte balance in newborns.
**Correct Answer: D. The maturation of the renal medulla, thick ascending limb of the loop of Henle, and the renin-angiotensin-aldosterone system (RAAS) allows the neonatal kidney to achieve concentrating ability equivalent to that of an adult kidney.**