All of the following are true except

Options

A. Renin is secreted by Juxta glomerular cell
B. Juxta-glomerular cells are present in afferent arterioles
C. Renin causes conversion of Angiotensino-gen to Angiotensin
D. Angiotensin II is a potent vasodilator

Answer

To solve the question, we need to evaluate each of the statements provided and identify which one is incorrect. Here’s a step-by-step breakdown of the solution:

### Step 1: Analyze each statement

1. **Statement 1**: "Renin is secreted by juxtaglomerular cells."
- This statement is **true**. Juxtaglomerular cells are specialized smooth muscle cells in the kidney that secrete the enzyme renin.

2. **Statement 2**: "Juxtaglomerular cells are present in efferent arterioles."
- This statement is **false**. Juxtaglomerular cells are actually located in the **afferent arterioles** of the nephron, not the efferent arterioles.

3. **Statement 3**: "Renin causes conversion of angiotensinogen to angiotensin."
- This statement is **true**. Renin acts on angiotensinogen (produced by the liver) to convert it into angiotensin I, which is further converted to angiotensin II.

4. **Statement 4**: "Angiotensin II is a potent vasodilator."
- This statement is **false**. Angiotensin II is actually a potent **vasoconstrictor**, which means it narrows blood vessels, increasing blood pressure.

### Step 2: Identify the incorrect statement
From the analysis, we see:
- Statement 1 is true.
- Statement 2 is false (incorrect).
- Statement 3 is true.
- Statement 4 is false (incorrect).

Since the question asks for the statement that is not true, we find that **Statement 2** is the one that is incorrect.

### Final Answer
The incorrect statement is: **"Juxtaglomerular cells are present in efferent arterioles."**

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