Question

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

(a) a reduction in insulin secretion from pancreas

(b) a reduction in vasopressin secretion from posterior pituitary

(c) a fall in the glucose concentration in urine

(d) an increase in secretion of glucagon.

Answer 1

Correct option (b) a reduction in vasopressin secretion from posterior pituitary

Explanation :

Vasopressin or ADH secreted from posterior pituitary stimulates reabsorption of water by the distal convoluted tubule and the collecting renal tubules and thus regulates urine volume. It has no such important effect on glucose metabolism. Therefore, a person whose blood glucose level is normal. but passes much urine and drinks much water has a reduction in vasopressin secretion which ultimately leads to diabetes insipidus.