A person passes much urine and drinks much water but his blood glucose level is normal. This condition may be the result of

Options

A. A reduction in insulin secretion from pancreas
B. A reduction in vasopressin secretion from posterior pituitary
C. A fall in the glucose concentraion in urine
D. An increase in secretion of glucagons

Answer

To solve the question, we need to analyze the symptoms presented: a person who passes much urine (polyuria) and drinks much water (polydipsia), but has a normal blood glucose level. Let's break down the possible causes step by step.

### Step-by-Step Solution:

1. **Understanding the Symptoms**:
- The person experiences polyuria (excessive urination) and polydipsia (excessive thirst).
- Importantly, the blood glucose level is normal, which rules out diabetes mellitus as a cause of the symptoms.

2. **Identifying Possible Causes**:
- The symptoms of excessive urination and thirst can be indicative of several conditions, but the normal blood glucose level is a key factor.
- Common conditions that can cause these symptoms include diabetes insipidus and certain hormonal imbalances.

3. **Considering Diabetes Insipidus**:
- Diabetes insipidus is a condition characterized by a deficiency of vasopressin (also known as antidiuretic hormone, ADH), which is produced by the posterior pituitary gland.
- A lack of vasopressin leads to the kidneys not being able to concentrate urine, resulting in large volumes of dilute urine and increased thirst.

4. **Evaluating Hormonal Secretion**:
- Since the blood glucose level is normal, we can rule out issues related to insulin secretion or glucose metabolism.
- The reduction in vasopressin secretion is a likely cause of the symptoms described.

5. **Conclusion**:
- Given that the person has normal blood glucose levels, the most plausible explanation for the symptoms of excessive urination and thirst is a reduction in vasopressin secretion from the posterior pituitary gland.

### Final Answer:
The condition may be the result of a reduction in vasopressin secretion from the posterior pituitary.

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