ATI RN
Endocrine System Test Questions Questions
Question 1 of 5
A young man presents with a blood pressure of 175/110 mm Hg. He is found to have a high circulating aldosterone but a low circulating cortisol. Glucocorticoid treatment lowers his circulating aldosterone and lowers his blood pressure to 140/85 mm Hg. He probably has an abnormal
Correct Answer: A
Rationale: The correct answer is A: 17α-hydroxylase. In this scenario, the patient presents with hypertension, high aldosterone, and low cortisol levels. This pattern suggests a defect in the enzyme 17α-hydroxylase, which is responsible for both cortisol and aldosterone synthesis. Glucocorticoid treatment lowers aldosterone levels and subsequently normalizes blood pressure. The other choices (B: 21β-hydroxylase, C: 3β-hydroxysteroid dehydrogenase, D: aldosterone synthase) are not implicated in this specific presentation and do not align with the observed hormone levels and response to glucocorticoid therapy.
Question 2 of 5
The growth hormone produced by the pituitary gland is known as _______.
Correct Answer: A
Rationale: The correct answer is A: somatotropin. The growth hormone produced by the pituitary gland is known as somatotropin. - "Somato" refers to the body, indicating its role in regulating body growth. - "Tropin" refers to stimulation, emphasizing its function in promoting cell growth and regeneration. - Prolactin (B) is responsible for milk production. - Luteinizing hormone (C) and follicle-stimulating hormone (D) are involved in reproductive functions, not growth regulation.
Question 3 of 5
Which of the following hormones acts on its target tissues by a steroid hormone mechanism of action?
Correct Answer: A
Rationale: The correct answer is A: Thyroid hormone. Thyroid hormone acts on its target tissues by a steroid hormone mechanism of action because it is a lipid-soluble hormone that can diffuse through cell membranes and bind to intracellular receptors. These hormone-receptor complexes then directly regulate gene expression. In contrast, choices B, C, and D do not follow a steroid hormone mechanism of action. Parathyroid hormone (PTH) acts through G-protein coupled receptors, Antidiuretic hormone (ADH) acts through V2 receptors, and β1 adrenergic agonists act through beta-adrenergic receptors, which are all distinct from the mechanism of action of steroid hormones.
Question 4 of 5
Growth hormone ________.
Correct Answer: D
Rationale: The correct answer is D because growth hormone promotes long bone growth during the formative years by stimulating the growth plates in bones. This hormone plays a crucial role in skeletal growth and development. Choice A is incorrect because somatostatin is a different hormone that inhibits growth hormone release. Choice B is incorrect because growth hormone is primarily regulated by neural mechanisms. Choice C is incorrect because growth hormone actually promotes muscle growth and reduces fat mass.
Question 5 of 5
Cells that respond to peptide hormones usually do so through a sequence of biochemical reactions involving receptor and kinase activation. In order for cells to respond, it is necessary for first and second messengers to communicate. This is possible because ________.
Correct Answer: C
Rationale: The correct answer is C: G protein acts as the link between first and second messengers. Rationale: 1. Peptide hormones cannot enter the cell membrane due to their large size. 2. Hormones do not directly stimulate genes; they act through signaling pathways. 3. G proteins are key in transmitting signals from hormone receptors to second messengers, facilitating cellular responses. 4. The hormone receptor complex typically stays on the cell membrane to initiate signaling cascades.