Juxtamedullary nephrons are much efficient in reabsorption of components because

Options

A. they are found adjacent area of cortex with medulla
B. they have larger Bowman's capsules
C. they have long loop of Henle and well developed vasa recta
D. they are present in desert animals only

Answer

**Step-by-Step Solution:**

1. **Understanding Juxtamedullary Nephrons**:
- Juxtamedullary nephrons are a type of nephron located near the junction of the renal cortex and medulla. They play a crucial role in the concentration of urine.

2. **Identifying Key Features**:
- The primary distinguishing feature of juxtamedullary nephrons is their long loop of Henle. This structure extends deep into the medulla, which is essential for the reabsorption process.

3. **Role of the Loop of Henle**:
- The long loop of Henle allows for a greater surface area for reabsorption. This structure facilitates the countercurrent multiplication mechanism, which is vital for concentrating urine and reabsorbing water and solutes.

4. **Well-Developed Vasa Recta**:
- Juxtamedullary nephrons also have well-developed vasa recta, which are blood vessels that run parallel to the loop of Henle. This arrangement helps maintain the osmotic gradient in the medulla, further enhancing the reabsorption of water.

5. **Comparison with Cortical Nephrons**:
- In contrast, cortical nephrons have shorter loops of Henle and are primarily involved in the filtration process rather than concentrating urine. This makes juxtamedullary nephrons more efficient in reabsorption.

6. **Conclusion**:
- Therefore, the efficiency of juxtamedullary nephrons in reabsorbing components is primarily due to their long loop of Henle and well-developed vasa recta, which together facilitate the concentration of urine and the reabsorption of essential substances.

**Final Answer**: Juxtamedullary nephrons are much more efficient in reabsorption of components because they have a long loop of Henle and well-developed vasa recta.

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