Correct Answer: A

Rationale: The receptors for non-steroid peptide hormones are typically found on the plasma membrane of target cells. These hormones are large or polar molecules that cannot easily diffuse through the cell membrane. Instead, they bind to specific receptors on the cell surface, initiating signaling pathways that eventually lead to changes within the cell. Once the peptide hormone binds to its receptor on the plasma membrane, secondary messenger systems are activated to relay the signal into the cell and initiate the appropriate cellular response. This distinct mechanism of action highlights the importance of the plasma membrane as the location of receptors for non-steroid peptide hormones.

Correct Answer: A

Rationale: The receptors for non-steroid peptide hormones are typically found on the plasma membrane of target cells. These hormones are large or polar molecules that cannot easily diffuse through the cell membrane. Instead, they bind to specific receptors on the cell surface, initiating signaling pathways that eventually lead to changes within the cell. Once the peptide hormone binds to its receptor on the plasma membrane, secondary messenger systems are activated to relay the signal into the cell and initiate the appropriate cellular response. This distinct mechanism of action highlights the importance of the plasma membrane as the location of receptors for non-steroid peptide hormones.

Correct Answer: B

Rationale: Small cell (oat cell) carcinoma of the lung is most commonly associated with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). This paraneoplastic syndrome occurs in patients with small cell lung cancer due to the production of antidiuretic hormone (ADH) by the tumor cells. The excessive release of ADH leads to water retention and dilutional hyponatremia, causing symptoms such as nausea, confusion, seizures, and potentially life-threatening complications. Other types of lung cancer, such as squamous cell carcinoma, large cell carcinoma, and adenocarcinoma, are less commonly associated with SIADH.

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: 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.