A 10-year-old patient will be started on methylphenidate hydrochloride (Ritalin) therapy. The nurse will perform which essential baseline assessment before this drug is started?

Correct Answer: B

Rationale: The correct answer is B: Height and weight. Before starting methylphenidate therapy in a 10-year-old patient, it is essential to assess height and weight as this medication can affect growth and appetite. Monitoring these parameters at baseline helps establish a reference point for future assessment of treatment effects on growth. Eye examination (A) is important for long-term monitoring but not essential before starting therapy. Liver studies (C) are not typically required before starting methylphenidate therapy. Hearing test (D) is not directly related to starting this medication.

Correct Answer: C

Rationale: The correct answer is C: Thiazide diuretics. Thiazide diuretics are commonly used as first-line therapy for hypertension due to their effectiveness in reducing blood pressure by promoting diuresis. They work by inhibiting sodium reabsorption in the distal convoluted tubule, leading to decreased fluid volume and lower blood pressure. Thiazides are well-tolerated and have shown to reduce cardiovascular events in hypertensive patients. Loop diuretics (A) are more potent and are typically reserved for patients with more severe fluid overload conditions. Osmotic diuretics (B) are used for acute renal failure or cerebral edema, not for hypertension. Potassium-sparing diuretics (D) are typically used in combination with thiazides to prevent hypokalemia, not as initial therapy.

Correct Answer: D

Rationale: The correct answer is D because hydrophilic substances cannot permeate membranes by passive diffusion due to their polarity and inability to dissolve in the hydrophobic lipid bilayer. This prevents them from crossing the membrane without the assistance of transport proteins. A, B, and C are incorrect because lipid-soluble, non-ionized substances, and hydrophobic substances can easily pass through membranes by passive diffusion as they can dissolve in the lipid bilayer.

Correct Answer: D

Rationale: The correct answer is D: cAMP. G-protein-coupled receptors activate adenylyl cyclase, leading to the production of cAMP, which acts as the second messenger. cAMP then triggers downstream signaling cascades. Choice A (Adenylyl cyclase) is the enzyme activated by G-protein-coupled receptors, not a second messenger itself. Choice B (Sodium ions) is not typically involved in GPCR signaling pathways. Choice C (Phospholipase C) generates inositol trisphosphate and diacylglycerol, which are part of a separate signaling pathway, not the second messenger system for GPCRs.

Correct Answer: A

Rationale: The correct answer is A because Type A delta and C fibers are known to participate in high-frequency pain transmission. Type A delta fibers transmit sharp, localized pain signals, while Type C fibers transmit dull, aching pain signals. Choice B, Type A alpha fibers, are responsible for transmitting proprioceptive information. Choice C, Type B fibers, are not involved in pain transmission. Choice D, Type A beta fibers, are responsible for touch and pressure sensations, not high-frequency pain transmission. Therefore, based on the characteristics of each fiber type, Type A delta and C fibers are the correct choice for high-frequency pain transmission.