Question

Exophthalmic goitre occurs due to

• A. hyposecretion of thyroxine
• B. hypersecretion of thyroxine
• C. hypersecretion of thyrocalcitonin
• D. hyposecretion of thyrocalcitonin

Answer 1

The correct option is B hypersecretion of thyroxine

Exophthalmic goitre is an enlargement of the thyroid gland. Its typical feature is exophthalmos, i.e. bulging of the eyes. It occurs due to hyperthyroidism or hypersecretion of thyroxine.

Hyposecretion of thyroxine results in hypothyroidism, which reduces the basal metabolic rate of the body.

Thyrocalcitonin is also secreted by the thyroid gland, but it has no role in the basal metabolic rate. It helps in regulating blood calcium levels along with parathyroid hormone.