Nokea
Which of the following hormones acts on its target tissues by a steroid hormone mechanism of action?
- A. Thyroid hormone
- B. Parathyroid hormone (PTH)
- C. Antidiuretic hormone (ADH) on the collecting duct
- D. β1 adrenergic agonists
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.
You may also like to solve these questions
How do hormones affect target tissues?
- A. Hormones affect target tissues through the digestive system.
- B. Hormones affect target tissues through the nervous system.
- C. Hormones secrete mucus that then travels to target tissues.
- D. Hormones travel directly to target tissues and bind to receptors.
Correct Answer: D
Rationale: The correct answer is D because hormones are released into the bloodstream by endocrine glands and travel to specific target tissues, where they bind to receptors on the surface or within the cells. This binding triggers a series of cellular responses that regulate various physiological processes. Choices A, B, and C are incorrect because hormones do not affect target tissues through the digestive system, nervous system, or by secreting mucus. Hormones act specifically by binding to receptors on target cells to initiate their effects.
The action of acetylcholine is very short due to:
- A. Rapid hepatic metabolism
- B. Reuptake by nerve endings
- C. Binding to plasma proteins
- D. Hydrolysis by cholinesterase enzyme
Correct Answer: D
Rationale: The correct answer is D: Hydrolysis by cholinesterase enzyme. Acetylcholine is broken down by cholinesterase enzyme into choline and acetate, leading to the termination of its action. Rapid hepatic metabolism (A) is not the primary mechanism for acetylcholine breakdown. Reuptake by nerve endings (B) refers to reuptake of neurotransmitters, not breakdown. Binding to plasma proteins (C) does not affect the duration of acetylcholine action.
Virilization is characterized by:
- A. excess facial hair.
- B. buffalo hump.
- C. truncal obesity.
- D. gonadal atrophy.
Correct Answer: A
Rationale: The correct answer is A: excess facial hair. Virilization refers to the development of male secondary sexual characteristics in females due to increased androgen levels. Excess facial hair, known as hirsutism, is a classic sign of virilization. Buffalo hump (B) and truncal obesity (C) are associated with Cushing's syndrome, not virilization. Gonadal atrophy (D) refers to the shrinkage of the gonads and is not a typical feature of virilization.
Which of the following is an alpha-blocker used in the treatment of hypertension:
- A. Tyramine
- B. Prazosin
- C. Ergometrine
- D. Ergotamine
Correct Answer: B
Rationale: Step 1: Understand the question is about an alpha-blocker for hypertension.
Step 2: Identify Prazosin as an alpha-blocker used for hypertension by blocking alpha-1 receptors.
Step 3: Explain how Prazosin works to dilate blood vessels and lower blood pressure.
Step 4: Summarize why other choices are incorrect:
- A: Tyramine is not an alpha-blocker, it is found in certain foods.
- C: Ergometrine is an ergot alkaloid used for uterine contractions, not hypertension.
- D: Ergotamine is also an ergot alkaloid used for migraines, not hypertension.
When teaching the patient with diabetes about insulin administration, the nurse should include which instruction for the patient?
- A. Pull back on the plunger after inserting the needle to check for blood.
- B. Consistently use the same size of insulin syringe to avoid dosing errors.
- C. Clean the skin at the injection site with an alcohol swab before each injection.
- D. Rotate injection sites from arms to thighs to abdomen with each injection to prevent lipodystrophies.
Correct Answer: D
Rationale: Rotating injection sites is important to avoid lipodystrophies, which can impact insulin absorption.