Metabolic rate of the following organ is not significantly affected by thyroxine:

Correct Answer: A

Rationale: The metabolic rate of the brain is not significantly affected by thyroxine. Thyroxine mainly influences the metabolic rate of organs with high energy demands such as the heart, liver, and skeletal muscle. Thyroxine increases the metabolic rate by stimulating the production of enzymes involved in energy production and consumption. However, the brain has a relatively stable metabolic rate that is not significantly influenced by changes in thyroid hormone levels.

Correct Answer: D

Rationale: In this scenario, the correct answer is D) All of the above. The rationale behind this is that overtreatment with any of the thyroid inhibitors listed (Lugol's iodine, Radioactive iodine, and Carbimazole) can lead to enlargement of the thyroid, a condition known as goiter. Lugol's iodine is a solution containing molecular iodine and potassium iodide, which can cause goiter if used in excess. Radioactive iodine, often used in the treatment of hyperthyroidism, can also lead to goiter if the dosage is too high. Carbimazole, a medication used to treat hyperthyroidism, can cause goiter as a side effect when overused or not properly monitored. To understand why the other options are incorrect, we can look at their individual mechanisms. Lugol's iodine and radioactive iodine are both forms of iodine that can affect thyroid function, but they are not the only substances that can cause goiter through overtreatment. Carbimazole, as mentioned earlier, is a medication that can also result in goiter if misused. In an educational context, it is crucial for students to grasp the potential consequences of overtreatment with thyroid inhibitors, as this knowledge is essential for healthcare professionals working with patients with thyroid disorders. Understanding the side effects and proper dosages of these medications is vital for providing safe and effective care to individuals with thyroid conditions.

Correct Answer: A

Rationale: Propranolol, a non-selective beta-blocker, is often used in hyperthyroidism as short-term symptomatic therapy to help manage symptoms such as tachycardia, tremors, and anxiety until the effect of carbimazole, an anti-thyroid medication, begins to take effect. Propranolol does not directly treat the underlying thyroid condition but can provide relief from some of the uncomfortable symptoms associated with hyperthyroidism. Once carbimazole starts to control the overproduction of thyroid hormones, the need for propranolol may decrease or even be eliminated. It is not typically used as long-term maintenance therapy or in cases where other anti-thyroid medications like carbimazole are effective.

Correct Answer: C

Rationale: Glucose entry into adipose tissue cells is highly dependent on the presence of insulin. Insulin plays a crucial role in promoting glucose uptake by inducing the translocation of glucose transporter proteins, particularly GLUT4, to the cell membrane of adipose tissue cells. This process allows the cells to take up glucose from the bloodstream, thereby regulating blood glucose levels. In the absence of insulin or in conditions of insulin resistance, such as in diabetes, glucose uptake by adipose tissue is impaired, leading to hyperglycemia.

Correct Answer: A

Rationale: The most common adverse reaction to insulin therapy is hypoglycemia. Insulin works by lowering blood sugar levels, but if too much insulin is administered or not enough food is consumed, it can result in blood sugar levels dropping too low, leading to hypoglycemia. Symptoms of hypoglycemia include shakiness, sweating, confusion, irritability, dizziness, fast heartbeat, and in severe cases, loss of consciousness or seizures. It is important for individuals on insulin therapy to monitor their blood sugar levels regularly and be aware of the signs and symptoms of hypoglycemia to address it promptly.