Question

Intake of ORS inhibits secretion of
A) Vasopressin
B) Oxytocin
C) Melatonin
D) Thyroxine

Answer 1

Hint:ORS is also known as oral rehydration solution. It contains drinking water with some amount of sugar and salt. The salt is particularly sodium and potassium. It is used to treat the dehydration that is water loss that occurs inside the body particularly due to diarrhoea.

Complete answer:
Whenever the hormone is involved in the reabsorption of water that is dehydration the ORS acts antagonist to it and inhibits its secretion as it is used to treat dehydration.
Now let us collect information about given option :
A) Vasopressin : its target tissue is mainly kidneys. It stimulates the reabsorption of water and electrolyte. It acts on the nephrons present in the kidney and increase the reabsorption of water from kidney tubules in contrast ORS helps in the hydration of the body so it will inhibit secretion of vasopressin
B) Oxytocin : it is also known as Pitocin and acts on the smooth muscles of the uterus. It stimulates and increases the contraction of the uterus and is helpful in the birth of a child. It is also helpful in ejection of milk from the mammary gland.
C) Melatonin : it is secreted by pineal gland. Melatonin hormone delays puberty in humans by opposing the action of LH and FSH and hence, affects the menstrual cycle and working of gonads. It is also concerned with sleep.
D) Thyroxine : it is secreted by thyroid gland. Thyroid hormones greatly increase the metabolic rate of the body and consequently, enhance heat production (calorigenic effect) and maintain BMR (basal metabolic rate).

Hence the correct answer is option ‘A’ vasopressin.

Note:Failure of secretion of vasopressin leads to a reduced renal reabsorption of water and a consequent elimination of a large volume of very dilute (hypotonic) urine, this disease is known as Diabetes Insipidus although the volume of urine is increased, no glucose appears in the urine of such patients. Besides its antidiuretic effect of reducing the urinary volume, vasopressin also enhances arterial blood pressure by causing constriction or narrowing of arterioles.