Juxta glomerular apparatus is formed by

Options

A. Modified cuboidal cells of DCT
B. Modified cuboidal cells of thick segment of descending limb of loop of Henle
C. Smooth muscle cells of vase recta
D. Cellular modifications in the distal convoluted tubule and the afferent arterioles at the location of their contact

Answer

To solve the question about the formation of the juxtaglomerular apparatus, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Juxtaglomerular Apparatus (JGA)**:
- The juxtaglomerular apparatus is a specialized structure located in the kidneys, specifically in the nephron, which is the functional unit of the kidney.

2. **Identifying the Components of JGA**:
- The JGA is primarily composed of modified cells that are involved in regulating blood pressure and the filtration rate of the kidneys.

3. **Analyzing the Options**:
- **Option A**: Modified cuboidal cells of DCT - This is incorrect because the distal convoluted tubule (DCT) does not have cuboidal cells; it has simple epithelial cells.
- **Option B**: Modified cuboidal cells of thick segments of descending limb of loop of Henle - This is also incorrect as the descending limb of the loop of Henle does not contribute to the JGA.
- **Option C**: Smooth muscles of vasa recta - This option is incorrect because the vasa recta are not part of the JGA structure.
- **Option D**: Cellular modifications at the distal convoluted tubule and afferent arterioles at the location of their contact - This is the correct option as the JGA is formed by the interaction of modified cells in the DCT and the afferent arterioles.

4. **Conclusion**:
- The juxtaglomerular apparatus is formed by cellular modifications at the distal convoluted tubule and the afferent arterioles where they come into contact.

### Final Answer:
The juxtaglomerular apparatus is formed by cellular modifications at the distal convoluted tubule and afferent arterioles at the location of their contact (Option D).

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