Correct Option
The correct option is 1 and 3 only.
Explanation
Exophthalmic goitre, commonly known as Graves' disease, is an autoimmune disorder that affects the thyroid gland. It is the most common cause of hyperthyroidism, characterized by the overproduction of thyroid hormones which regulate the body's metabolic rate.
Statement-wise Analysis
- Statement 1 is Correct: Exophthalmic goitre is a form of hyperthyroidism. In this condition, the thyroid gland enlarges and secretes excessive amounts of thyroid hormones (thyroxine or $T_4$ and triiodothyronine or $T_3$).
- Statement 2 is Incorrect: The term "exophthalmic" is derived from exophthalmos, which refers to the protrusion or bulging of the eyeballs, not sinking. This occurs due to inflammation and fluid accumulation in the tissues and muscles behind the eyes. Sinking of the eyeballs is known as enophthalmos, which is unrelated to this condition.
- Statement 3 is Correct: Thyroid hormones play a central role in regulating metabolism. An excess of these hormones leads to a significant increase in the Basal Metabolic Rate (BMR). Consequently, patients often experience weight loss despite having a normal or increased appetite, along with heat intolerance and tachycardia (increased heart rate).
Key Takeaway
Exophthalmic goitre (Graves' disease) is characterized by hyperthyroidism (overactive thyroid), enlargement of the thyroid gland, protrusion of the eyeballs (exophthalmos), and an increased Basal Metabolic Rate.