Which one is an important constituent of renin angiotensinogen-aldosterone system?

Options

A. JGA cell
B. Plasma cell
C. Glomerulus
D. Erythropoietin

Answer

**Step-by-Step Solution:**

1. **Understanding the Renin-Angiotensinogen-Aldosterone System (RAAS):**
- The RAAS is a hormone system that regulates blood pressure and fluid balance in the body. It involves several key components, including renin, angiotensinogen, angiotensin II, and aldosterone.

2. **Identifying the Key Components:**
- The question asks for an important constituent of the RAAS. The options provided are:
- JGA cell
- Plasma cell
- Glomerulus
- Erythropoietin

3. **Analyzing Each Option:**
- **JGA cell (Juxtaglomerular Apparatus cell):** These cells are located in the kidneys and are responsible for secreting renin. Renin initiates the conversion of angiotensinogen (produced by the liver) into angiotensin I, which is then converted to angiotensin II, a key player in increasing blood pressure.
- **Plasma cell:** These are B lymphocytes that produce antibodies and are not directly involved in the RAAS.
- **Glomerulus:** This structure is involved in the ultrafiltration of blood but does not play a direct role in the RAAS.
- **Erythropoietin:** This hormone is produced by the kidneys and is primarily involved in the production of red blood cells, not in the regulation of blood pressure.

4. **Conclusion:**
- The JGA cell is the most important constituent of the renin-angiotensinogen-aldosterone system because it is responsible for the secretion of renin, which triggers the entire cascade of events leading to blood pressure regulation.

5. **Final Answer:**
- The correct answer is **JGA cell**.

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