Correct Answer: C

Rationale: The correct answer is C: Ischaemic heart disease. Metabolic syndrome X consists of a cluster of conditions, including hyperlipidemia, obesity, hypertension, and insulin resistance. Ischaemic heart disease, while commonly associated with metabolic syndrome X due to the increased risk factors, is not a direct component of the syndrome itself. Therefore, it is not considered a part of metabolic syndrome X. Hyperlipidemia (A), obesity (B), and hypertension (D) are all key components of metabolic syndrome X due to their association with insulin resistance and increased risk of cardiovascular disease.

Correct Answer: C

Rationale: The correct answer is C: Oxytocin. The anterior pituitary gland produces several hormones, including adrenocorticotropic hormone (A), growth hormone (B), and thyroid-stimulating hormone (D). Oxytocin is actually produced by the posterior pituitary gland, not the anterior pituitary. Oxytocin is responsible for uterine contractions during childbirth and milk ejection during breastfeeding. Therefore, C is the correct answer as it is not produced by the anterior pituitary unlike the other hormones mentioned.

Correct Answer: C

Rationale: Elevated glucose levels in obese individuals are often due to insulin resistance. Insulin resistance occurs when the body's cells do not respond effectively to insulin, leading to decreased glucose uptake. This results in elevated blood glucose levels. Diabetic acidosis (choice A) is a complication of uncontrolled diabetes characterized by high blood ketone levels, not directly related to obesity. Glucose intolerance (choice B) refers to the body's inability to regulate blood glucose levels efficiently but is not specific to obesity. Insulin deficiency (choice D) is characteristic of type 1 diabetes, where the body does not produce enough insulin, which is distinct from insulin resistance seen in obesity.

Correct Answer: C

Rationale: Increased parathyroid hormone (PTH) concentration is associated with tetany because PTH helps regulate calcium levels in the blood. When calcium levels are low, PTH is released to stimulate the release of calcium from bones and increase calcium absorption from the intestines. Tetany is characterized by muscle cramps and spasms due to low calcium levels, which can occur when PTH levels are elevated. A: Vitamin D toxicity is associated with high levels of calcium in the blood, not low calcium levels as seen in tetany. B: Rickets is a condition caused by vitamin D deficiency, leading to impaired bone growth and development, not directly related to elevated PTH levels. D: Reduced excretion of phosphate is not directly linked to elevated PTH levels, as PTH primarily regulates calcium levels.

Correct Answer: A

Rationale: Aldosterone increases potassium excretion by promoting the reabsorption of sodium and water in the kidneys, leading to potassium excretion. This helps maintain electrolyte balance. Other choices are incorrect because aldosterone does not directly increase water loss, is released in response to low blood volume, and is deficient in Addison's disease.