Juxta glomerular apparatus (JGA) comprises of all of the following except:

Options

A. Macola densa cells
B. Juxta glomerular cells
C. Lacis cells
D. Principal cells

Answer

To solve the question regarding the components of the Juxta Glomerular Apparatus (JGA), we will follow these steps:

### Step 1: Understand the Juxta Glomerular Apparatus (JGA)
The JGA is a specialized structure located in the nephron of the kidney. It plays a crucial role in regulating blood pressure and the filtration rate of the glomerulus.

### Step 2: Identify the Components of JGA
The JGA consists of three main types of cells:
1. **Macula Densa Cells**: These are located in the wall of the distal convoluted tubule (DCT) and are sensitive to sodium chloride concentration.
2. **Juxta Glomerular (JG) Cells**: These cells are located in the wall of the afferent arterioles and are responsible for the secretion of renin.
3. **Lacy Cells**: Also known as extraglomerular mesangial cells, these are located between the macula densa and the JG cells.

### Step 3: Analyze the Options
Now, we need to determine which of the following is NOT a part of the JGA:
- Macula Densa Cells
- Juxta Glomerular Cells
- Lacy Cells
- Principal Cells

### Step 4: Identify the Incorrect Option
From our analysis:
- Macula Densa Cells, Juxta Glomerular Cells, and Lacy Cells are all components of the JGA.
- **Principal Cells** are not part of the JGA; they are cells found in the collecting ducts of the nephron.

### Conclusion
Thus, the correct answer is that the Juxta Glomerular Apparatus (JGA) comprises all of the following except **Principal Cells**.

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