Angiotensinogen is a protein produced and secreted by

Options

A. Macula densa cell
B. Liver cells
C. Juxtaglomerular cells
D. Endothelial cells

Answer

### Step-by-Step Solution:

1. **Understanding Angiotensinogen**:
- Angiotensinogen is a protein that plays a critical role in the regulation of blood pressure and fluid balance in the body. It is classified as a plasma protein.

2. **Identifying the Source**:
- The question asks where angiotensinogen is produced and secreted. To answer this, we need to identify which of the given options is responsible for its production.

3. **Reviewing the Options**:
- The options provided are:
- A) Macula densa cells
- B) Liver cells
- C) Juxtaglomerular cells
- D) Endothelial cells

4. **Analyzing Each Option**:
- **Macula Densa Cells**: These cells are part of the kidney and are involved in sensing sodium concentration but do not produce angiotensinogen.
- **Liver Cells**: The liver is known to produce angiotensinogen, which is released into the bloodstream. This makes it a key player in the renin-angiotensin system.
- **Juxtaglomerular Cells**: These cells are also located in the kidney and are involved in the secretion of renin, but they do not produce angiotensinogen.
- **Endothelial Cells**: These cells line blood vessels and have various functions, but they are not responsible for the production of angiotensinogen.

5. **Conclusion**:
- Based on the analysis, the correct answer is **B) Liver cells**, as they are the source of angiotensinogen.

### Final Answer:
Angiotensinogen is a protein produced and secreted by **liver cells**.

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