All the following are risk factors for the development of osteoporotic fractures except

Correct Answer: A

Rationale: While African race is considered a protective factor against the development of osteoporosis due to higher peak bone mass and lower fracture rates compared to other races, the other factors listed (current cigarette smoking, female sex, and physical inactivity) are all established risk factors for the development of osteoporotic fractures. African-American individuals, in general, have a lower risk of osteoporosis and fractures compared to Caucasians and Asians.

Correct Answer: D

Rationale: Thyroid-stimulating hormone (TSH) is a hormone produced by the anterior pituitary gland. It stimulates the thyroid gland to produce and release thyroid hormones, specifically thyroxine (T4) and triiodothyronine (T3). TSH secretion is regulated by the hypothalamus via the release of thyrotropin-releasing hormone (TRH). TRH acts on the anterior pituitary gland to stimulate the production and release of TSH. Therefore, TSH secretion is indeed inhibited by TRH, not stimulated as in the other options.

Correct Answer: B

Rationale: The earliest changes observed by ophthalmoscope in background retinopathy of diabetes is typically the presence of microaneurysms. These are small dilations of retinal capillaries due to weakening of the vessel walls caused by diabetes-induced damage. Microaneurysms are a hallmark sign of diabetic retinopathy and are often the first visible sign on retinal examination. Other changes in diabetic retinopathy, such as venous dilatation, increased capillary permeability, and arteriovenous shunts, may develop later in the disease process as it progresses.

Correct Answer: A

Rationale: Primary hyperparathyroidism is a condition characterized by the overproduction of parathyroid hormone (PTH) by the parathyroid glands, leading to elevated levels of calcium in the blood. This excessive calcium can cause calcification in various tissues, including the basal ganglia of the brain. The calcification of the basal ganglia in primary hyperparathyroidism is a well-known radiological finding and can be visualized on imaging studies such as CT scans or MRI. Hypoparathyroidism, on the other hand, is characterized by low levels of PTH and results in decreased serum calcium levels, making it an unlikely cause of basal ganglia calcification. Secondary hyperparathyroidism is associated with chronic kidney disease and is also characterized by high PTH levels, but basal ganglia calcification is not a typical manifestation of this condition. Milk-alkali syndrome is a disorder characterized by excessive intake of

Correct Answer: A

Rationale: While African race is considered a protective factor against the development of osteoporosis due to higher peak bone mass and lower fracture rates compared to other races, the other factors listed (current cigarette smoking, female sex, and physical inactivity) are all established risk factors for the development of osteoporotic fractures. African-American individuals, in general, have a lower risk of osteoporosis and fractures compared to Caucasians and Asians.

Correct Answer: C

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: D

Rationale: Binding proteins are essential in transporting hormones through the bloodstream and protecting them from rapid degradation by enzymes. These proteins do not actually mediate the hormonal effects themselves. Hormonal effects are typically mediated by the hormone-receptor interactions at target cells. Binding proteins primarily serve as carriers for hormones and maintain their stability and availability in the circulation.

Correct Answer: A

Rationale: Thyrotoxicosis typically presents with hypermetabolism and various neuromuscular manifestations. Myasthenic syndrome, which involves muscle weakness and fatigability, is not a common neuromuscular feature of thyrotoxicosis. Instead, manifestations such as brisk knee jerk reflexes, hypokalaemic periodic paralysis (due to shifts in potassium levels), and hyperkinesia (excessive movement) are more commonly observed in patients with thyrotoxicosis. Myasthenic syndrome is more commonly associated with autoimmune disorders affecting the neuromuscular junction, such as myasthenia gravis.

Correct Answer: B

Rationale: Sheehan's syndrome, also known as postpartum hypopituitarism, is a condition characterized by pituitary gland dysfunction due to severe blood loss during childbirth, resulting in ischemic necrosis of the pituitary gland. As a consequence of pituitary hormone deficiency, one of the hallmark manifestations of Sheehan's syndrome is persistent lactation despite stopping breastfeeding. This occurs due to inadequate prolactin inhibition, leading to continuous milk production. Other common symptoms of Sheehan's syndrome include fatigue, weight loss, menstrual irregularities, hypothyroidism, adrenal insufficiency, and other pituitary hormone deficiencies. Cardiac failure, fever, and striking cachexia are not typical presentations associated with Sheehan's syndrome.