Which pituitary hormone is responsible for enhancing the arterial blood pressure by causing the narrowing of arterioles ?

Options

A. ACTH
B. Somatotropin
C. ADH
D. LTH

Answer

To determine which pituitary hormone is responsible for enhancing arterial blood pressure by causing the narrowing of arterioles, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Hormones**: We need to consider the hormones released by the pituitary gland. The options given are:
- Adenocorticotrophic hormone (ACTH)
- Somatotrophin (Growth Hormone)
- Antidiuretic hormone (ADH)
- Luteinizing hormone (LH)

2. **Analyze Each Hormone**:
- **Adenocorticotrophic hormone (ACTH)**: This hormone primarily stimulates the adrenal cortex to release glucocorticoids and mineralocorticoids. It does not directly cause vasoconstriction or affect arterial blood pressure.
- **Somatotrophin (Growth Hormone)**: This hormone is mainly responsible for growth and metabolism. It does not play a role in vasoconstriction or blood pressure regulation.
- **Antidiuretic hormone (ADH)**: Also known as vasopressin, this hormone is released from the posterior pituitary. ADH promotes water retention in the kidneys and can also cause vasoconstriction, which increases arterial blood pressure.
- **Luteinizing hormone (LH)**: This hormone is involved in regulating the reproductive system, particularly ovulation in females. It does not affect blood pressure.

3. **Determine the Correct Hormone**: From the analysis, ADH is the hormone that is responsible for causing vasoconstriction, which in turn enhances arterial blood pressure.

4. **Conclusion**: The correct answer to the question is **Antidiuretic hormone (ADH)**, as it is responsible for narrowing arterioles and increasing arterial blood pressure.

### Final Answer:
The pituitary hormone responsible for enhancing arterial blood pressure by causing the narrowing of arterioles is **Antidiuretic hormone (ADH)**.

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