Free endocrinology MCQ exam model for clinical students

Explanation:

• Prolonged corticosteroid therapy → Correct because iatrogenic Cushing syndrome is most common.

• Adrenal adenoma → Incorrect because it causes endogenous Cushing syndrome.

• Pituitary adenoma → Incorrect because it causes Cushing disease.

• Ectopic ACTH secretion → Incorrect because it is less common.

• Adrenal carcinoma → Incorrect because it is rare.

Explanation:

• Hormones and endocrine glands → Correct because endocrinology studies hormone secretion and action.

• Blood → Incorrect because this is hematology.

• Nervous system → Incorrect because this is neurology.

• Immune system → Incorrect because this is immunology.

• Digestive enzymes → Incorrect because this is gastroenterology.

Explanation:

• Hypocalcemia → Correct because low PTH reduces calcium levels.

• Hypercalcemia → Incorrect because it occurs in hyperparathyroidism.

• Hypernatremia → Incorrect because sodium is unaffected.

• Hypokalemia → Incorrect because potassium is not directly affected.

• Hyperphosphatemia only → Incorrect because hypocalcemia is key.

Explanation:

• Graves disease → Correct because autoimmune stimulation of TSH receptors causes hyperthyroidism.

• Toxic multinodular goiter → Incorrect because it is common in elderly but not most common overall.

• Thyroid adenoma → Incorrect because it is less common.

• Subacute thyroiditis → Incorrect because it causes transient hyperthyroidism.

• Iodine excess → Incorrect because it is an uncommon cause.

Explanation:

• Aldosterone and cortisol → Correct because adrenal cortex destruction causes deficiency.

• Insulin → Incorrect because it causes diabetes mellitus.

• Thyroxine → Incorrect because it causes hypothyroidism.

• Parathyroid hormone → Incorrect because it affects calcium.

• Antidiuretic hormone → Incorrect because it causes diabetes insipidus.

Explanation:

• Enlarged hands and feet → Correct because excess growth hormone after epiphyseal closure causes acromegaly.

• Short stature → Incorrect because it occurs in GH deficiency.

• Moon face → Incorrect because it is seen in Cushing syndrome.

• Central obesity → Incorrect because it is Cushing syndrome.

• Thin skin → Incorrect because it is seen in hypercortisolism.

Explanation:

• Antidiuretic hormone → Correct because it is released from posterior pituitary.

• Growth hormone → Incorrect because it is anterior pituitary hormone.

• Thyroid-stimulating hormone → Incorrect because it is anterior pituitary.

• Prolactin → Incorrect because it is anterior pituitary.

• Adrenocorticotropic hormone → Incorrect because it is anterior pituitary.

Explanation:

• HbA1c → Correct because it reflects average blood glucose over 3 months.

• Random blood glucose → Incorrect because it varies widely.

• Fasting plasma glucose → Incorrect because it reflects short-term control.

• Oral glucose tolerance test → Incorrect because it is diagnostic, not screening.

• Urine glucose → Incorrect because it is insensitive.

Explanation:

• Insulin → Correct because it facilitates glucose uptake by cells.

• Glucagon → Incorrect because it raises blood glucose.

• Cortisol → Incorrect because it promotes gluconeogenesis.

• Growth hormone → Incorrect because it increases glucose levels.

• Epinephrine → Incorrect because it raises blood glucose.

Explanation:

• Insulin resistance → Correct because peripheral tissues fail to respond to insulin.

• Autoimmune beta-cell destruction → Incorrect because it causes type 1 diabetes.

• Absolute insulin deficiency → Incorrect because insulin is present initially.

• Increased insulin sensitivity → Incorrect because it is opposite.

• Excess glucagon secretion only → Incorrect because resistance is primary.