Question

A person passes much urine and drinks much water but his blood glucose level remains normal. This condition may be the result of
A. reduction in insulin secretion from pancreas.
B. 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

In general if the person passes more urine daily with more thirst means there may be any systematic conditions such as diabetes, or any kidney related diseases or any hormone imbalance which may alter the normal physiology of the person.

Complete answer:
-From the first option, insulin is the hormone secreted by the beta cells of pancreas, where insulin is helpful for the absorption of glucose into the cells, and decrease the blood glucose cells, and decrease in the production of insulin causes diabetes but in the question itself they gave that not because of blood glucose levels, so the option A, C and D that all are related to blood glucose so they all are wrong options.
-When coming to Option B that is regarding the Vasopressin, it is also called as antidiuretic hormone, which is secreted by posterior pituitary gland, and the function is to maintain the tonicity of body, where in case of any hypertonic condition, it causes the kidney to absorb more water from the filtrate and decrease the hypertonicity, and decrease or reduction in hormone causes the more urine and more thirst which is called as diabetes insipidus.
So the correct option is B.

Note: Vasopressin or antidiuretic hormone is secreted by the posterior pituitary gland, where decrease in secretion or any less sensitivity of this hormone to the kidneys result in conditions such as polyuria, polydipsia, and increased in blood sodium such as hypernatremia, etc.