Correct Option
The correct option is Juxtamedullary nephrons.
Explanation
Nephrons, the structural and functional units of the kidney, are classified into two types based on the location of their renal corpuscles in the cortex and the length of the Loop of Henle. These two types are Cortical nephrons and Juxtamedullary nephrons.
Detailed Analysis
- Juxtamedullary Nephrons: These nephrons have their renal corpuscles located at the junction of the cortex and the medulla. They are characterized by a very long Loop of Henle that runs deep into the medulla. They constitute approximately 15-20% of the total nephrons and are associated with the vasa recta. They play a critical role in the concentration of urine via the counter-current mechanism.
- Cortical Nephrons: These constitute the majority (about 80-85%) of nephrons. Their renal corpuscles are situated close to the kidney surface. They possess a short Loop of Henle that extends only very little into the medulla. The vasa recta is either absent or highly reduced in these nephrons.
- Peritubular and Subcapsular: "Peritubular" refers to the capillary network surrounding the renal tubules, not a type of nephron. "Subcapsular" is not a standard classification for nephrons with long loops; it generally refers to cortical nephrons located immediately beneath the renal capsule.
Key Takeaway
Juxtamedullary nephrons are distinguished by their long Loops of Henle extending deep into the renal medulla, enabling the kidney to produce concentrated urine.