Which of the following mechanism will operate mainly to check variation in flow to the glomerulus in case of fluctuation in blood pressure?

Options

A. Counter current mechanism
B. Myogenic mechanism
C. Adam's stoke condition
D. Neurogenic mechanism

Answer

To solve the question, "Which of the following mechanisms will operate mainly to check variation in flow to the glomerulus in case of fluctuation in blood pressure?", we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question is asking which mechanism helps regulate blood flow to the glomerulus when blood pressure fluctuates. The glomerulus is a network of capillaries in the kidney that filters blood.

2. **Identify the Options**: The options provided are:
- A) Counter current mechanism
- B) Myogenic mechanism
- C) Adam's rock condition
- D) Neurogenic mechanism

3. **Analyze Each Option**:
- **A) Counter current mechanism**: This mechanism is primarily involved in the concentration of urine, not in regulating blood flow to the glomerulus. Therefore, this option is incorrect.

- **B) Myogenic mechanism**: This mechanism refers to the response of blood vessels (particularly arterioles) to changes in blood pressure. When blood pressure increases, the smooth muscle in the walls of the arterioles contracts, leading to a decrease in blood flow to the glomerulus, and vice versa. This mechanism helps maintain a relatively constant blood flow to the glomerulus despite fluctuations in systemic blood pressure. Thus, this option is correct.

- **C) Adam's rock condition**: This condition is related to a syndrome that involves loss of consciousness due to decreased cardiac output. It does not pertain to the regulation of blood flow to the glomerulus, making this option incorrect.

- **D) Neurogenic mechanism**: This mechanism involves the nervous system's control over blood vessels. While it can influence blood flow, it is not the primary mechanism for regulating blood flow to the glomerulus in response to blood pressure changes. Therefore, this option is also incorrect.

4. **Conclusion**: After analyzing all options, the correct answer is **B) Myogenic mechanism**. This mechanism is primarily responsible for regulating blood flow to the glomerulus in response to fluctuations in blood pressure.

### Final Answer:
**B) Myogenic mechanism**