Which of the following hormones are stored in the posterior pituitary gland?

Correct Answer:

Rationale: Oxytocin and Vasopressin, also known as antidiuretic hormone (ADH), are the hormones stored in the posterior pituitary gland. These hormones are produced by the hypothalamus and then transported and stored in the posterior pituitary gland until they are released into the bloodstream when needed. Oxytocin plays a role in uterine contractions during childbirth and milk ejection during lactation, while Vasopressin regulates water balance in the body by acting on the kidneys to reduce urine production and conserve water. The other hormones listed, such as Prolactin, TSH, GH, ACTH, FSH, and LH, are produced by the anterior pituitary gland.

Correct Answer: A

Rationale: Acromegaly is a disorder caused by excessive growth hormone production by the pituitary gland in adults, leading to an increase in muscle mass (hypertrophy). Hoffman syndrome, characterized by increased muscle mass with slowness of activity, is a clinical feature often seen in individuals with acromegaly. The excessive growth hormone levels in acromegaly can cause acral growth, soft tissue swelling, and muscle hypertrophy, contributing to the characteristic features of the condition, including Hoffman syndrome. Therefore, the correct answer is Acromegaly.

Correct Answer: B

Rationale: Excess prolactin typically causes gynecomastia in men. Prolactin is a hormone primarily responsible for milk production in women. However, in men, elevated levels of prolactin can lead to various symptoms, with gynecomastia being one of the most common. Gynecomastia is the development of breast tissue in males, which can result in swelling and tenderness of the breasts. It is important to investigate the underlying cause of elevated prolactin levels as it could be due to various conditions such as pituitary tumors, certain medications, or thyroid disorders.

Correct Answer: D

Rationale: The most common cause of Cushing's syndrome is a pituitary adenoma, specifically a corticotroph adenoma. This adenoma leads to excessive secretion of adrenocorticotropic hormone (ACTH) by the pituitary gland, which in turn stimulates the adrenal glands to produce high levels of cortisol. This results in the symptoms and signs characteristic of Cushing's syndrome. Pituitary adenomas are responsible for around 70-80% of cases of Cushing's syndrome, making it the most common cause.

Correct Answer: A

Rationale: Phaeochromocytoma may be associated with Medullary carcinoma of thyroid, Hyperparathyroidism, and Addison's disease as part of MEN Syndrome (Multiple Endocrine Neoplasia) Type 2. However, it is not typically associated with Neurofibromatosis. Neurofibromatosis is associated with the development of benign tumors of nerve tissue and is not directly linked to the presence of Phaeochromocytoma.

Correct Answer: B

Rationale: Diabetes Insipidus is a condition characterized by the body's inability to properly regulate water balance, leading to excessive urination and extreme thirst. This disorder is caused by a deficiency of vasopressin, also known as antidiuretic hormone (ADH). Vasopressin is a hormone produced by the hypothalamus and released by the pituitary gland to help regulate water balance in the body by controlling the amount of water reabsorbed by the kidneys. The lack of vasopressin in Diabetes Insipidus results in the kidneys producing a large volume of dilute urine, leading to dehydration and electrolyte imbalances.

Correct Answer: D

Rationale: Addison's disease, also known as primary adrenal insufficiency, is mainly caused by the autoimmune destruction of the adrenal cortex. This results in the inadequate production of hormones such as cortisol and aldosterone by the adrenal glands. While other conditions such as Adrenoleukodystrophy, Pyelonephritis, and Tuberculosis can also affect the adrenal glands, they are not known to be direct causes of Addison's disease.

Correct Answer: A

Rationale: Addison's disease, also known as primary adrenal insufficiency, is a condition where the adrenal glands do not produce enough steroid hormones, mainly cortisol and sometimes aldosterone. This deficiency in steroid hormone production is typically caused by autoimmune destruction of the adrenal cortex. Without enough cortisol and aldosterone, various symptoms may arise, such as fatigue, weight loss, low blood pressure, and skin discoloration. Therefore, option A accurately describes the nature of Addison's disease.

Correct Answer: C

Rationale: The gold standard for diagnosing acromegaly is the oral glucose tolerance test (OGTT) along with growth hormone (GH) measurement. During this test, the patient is given a glucose solution to drink, and then blood samples are taken to measure GH levels at specific time intervals. In a person without acromegaly, glucose ingestion would typically suppress GH levels. However, in individuals with acromegaly, GH levels remain elevated even after glucose administration due to the inability of glucose to inhibit GH release from the tumor.