All of the following are consistent with non-proliferative diabetic retinopathy except:

Correct Answer: C

Rationale: The correct answer is C: Neovascularization. Non-proliferative diabetic retinopathy is characterized by early changes such as retinal vascular microaneurysms, blot hemorrhages, and cotton-wool spots. Neovascularization is a feature of proliferative diabetic retinopathy, not non-proliferative. Neovascularization refers to the growth of abnormal new blood vessels in the retina, which can lead to severe vision loss if not treated promptly. In summary, neovascularization is not consistent with non-proliferative diabetic retinopathy, as it is a hallmark of the proliferative stage.

Correct Answer: C

Rationale: Erythropoietin is primarily secreted from the kidney, specifically by the Juxtaglomerular cells in the kidney's cortex. These cells are responsible for sensing oxygen levels and regulating erythropoietin production accordingly. Mesenchymal tumors, cerebellar haemangioblastoma, and lymphoma are not associated with erythropoietin secretion, making them incorrect choices. Mesenchymal tumors originate from connective tissues, cerebellar haemangioblastoma is a type of brain tumor, and lymphoma is a cancer of the lymphatic system. Only the Juxtaglomerular cells in the kidney have the physiological role of secreting erythropoietin in response to hypoxia.

Correct Answer: C

Rationale: The correct answer is C: SIADH. Secondary hyperaldosteronism is characterized by increased aldosterone production due to factors outside of the adrenal glands, such as increased renin-angiotensin-aldosterone system activation. SIADH does not involve aldosterone, but rather involves inappropriate secretion of antidiuretic hormone leading to hyponatremia. In contrast, congestive cardiac failure, nephrotic syndrome, and cirrhosis of the liver can all lead to secondary hyperaldosteronism due to mechanisms such as decreased effective circulating volume, renal hypoperfusion, and increased angiotensin II levels, respectively.

Correct Answer: B

Rationale: Correct Answer: B (Rheumatic carditis) Rationale: 1. Rheumatic carditis is a heart condition, which may lead to a decreased cardiac output and subsequently a lower pulse rate during sleep. 2. Anxiety neurosis can lead to increased sympathetic activity, causing an elevated pulse rate during sleep. 3. Pulmonary tuberculosis can cause systemic inflammation and increased metabolic demand, resulting in an elevated pulse rate during sleep. 4. Atropine, a parasympatholytic drug, inhibits the action of the parasympathetic nervous system, leading to an increased pulse rate.

Correct Answer: B

Rationale: The correct answer is B: Cretinism. Cretinism is the most common cause of preventable mental deficiency worldwide due to severe iodine deficiency during pregnancy. Iodine is crucial for thyroid hormone production, which is essential for fetal brain development. Beriberi disease (A) is caused by thiamine deficiency and affects the nervous system, not mental deficiency. Folate deficiency (C) can cause neural tube defects but not mental deficiency. Vitamin A deficiency (D) can lead to blindness and immune system issues, but not the most common cause of preventable mental deficiency.

Correct Answer: B

Rationale: Thyroid acropathy, also known as thyroid dermopathy, is a skin condition commonly associated with Graves' disease. This autoimmune disorder causes an overactive thyroid gland, leading to high levels of thyroid hormones in the blood. The excess thyroid hormones can trigger changes in the skin, resulting in thyroid acropathy. Subclinical hypothyroidism (choice A) is characterized by slightly elevated TSH levels with normal thyroid hormone levels, not typically associated with thyroid acropathy. Myxoedema (choice C) refers to severe hypothyroidism and is not linked to thyroid acropathy. Medullary carcinoma of the thyroid (choice D) is a type of thyroid cancer and is not known to cause thyroid acropathy. Therefore, the correct answer is B, Graves' disease, as it is the most common condition associated with thyroid acropathy.

Correct Answer: D

Rationale: The correct answer is D: Thyroxine-binding globulin (TBG). TBG is the primary source of bound T4 in the plasma as it specifically binds to and transports thyroid hormones. This protein has the highest affinity for T4 compared to other plasma proteins. Albumin (A) and gamma globulins (B) can also bind to thyroid hormones, but TBG is the primary carrier. Thyroid peroxidase (C) is an enzyme involved in thyroid hormone production, not in binding T4 in the plasma.

Correct Answer: A

Rationale: The correct answer is A because ADH secretion is increased during stress to retain water in the body. This response helps maintain blood pressure and prevent dehydration under stressful conditions. Choice B is incorrect because ADH secretion is actually increased during hemorrhage to conserve water. Choice C is incorrect because increased blood osmolality triggers ADH secretion to retain water. Choice D is incorrect because alcohol inhibits ADH secretion, leading to increased urine production.

Correct Answer: B

Rationale: Step-by-step rationale for why answer B is correct: 1. Cushing's syndrome is characterized by excess cortisol production. 2. Women are more likely to develop Cushing's syndrome due to hormonal differences. 3. Women have higher cortisol levels naturally, making them more susceptible. 4. Men can still develop Cushing's syndrome but at a lower rate compared to women. Summary: A: Incorrect, as women are more likely to develop Cushing's syndrome. C: Incorrect, as the incidence is higher in women due to hormonal factors. D: Incorrect, as it refers to thyroid hormones, not cortisol in Cushing's syndrome.