which electrolyte is important in the formation of the thyroid hormones

ATI RN

ATI Fluid and Electrolytes

1. Which electrolyte is important in the formation of the thyroid hormones?

A. Sodium
B. Iodine
C. Iron
D. Chloride

Correct answer: B

Rationale: Iodine is the correct answer because it is essential for the synthesis of thyroid hormones. The thyroid gland incorporates iodine into thyroid hormones such as thyroxine (T4) and triiodothyronine (T3). These hormones are crucial for regulating metabolism, growth, and development. Sodium, iron, and chloride are not directly involved in the formation of thyroid hormones, making them incorrect choices.

2. A nurse in the neurologic ICU has orders to infuse a hypertonic solution into a patient with increased intracranial pressure. This solution will increase the number of dissolved particles in the patient's blood, creating pressure for fluids in the tissues to shift into the capillaries and increase the blood volume. This process is best described as which of the following?

A. Hydrostatic pressure
B. Osmosis and osmolality
C. Diffusion
D. Active transport

Correct answer: B

Rationale: The correct answer is B: Osmosis and osmolality. Osmosis is the movement of fluid from a region of low solute concentration to a region of high solute concentration across a semipermeable membrane. In this case, the hypertonic solution increases the number of dissolved particles in the blood, causing fluids to shift into the capillaries due to the osmotic pressure gradient. Osmolality refers to the concentration of solutes in a solution. Hydrostatic pressure refers to changes in water or volume related to water pressure, not the movement of fluids due to solute concentration differences. Diffusion is the movement of solutes from an area of greater concentration to lesser concentration; in an intact vascular system, solutes are unable to move freely, so diffusion does not play a significant role in this scenario. Active transport involves the movement of molecules against the concentration gradient with the use of energy, typically at the cellular level, and is not related to the vascular volume changes described in the question.

3. Third spacing occurs when fluid moves out of the intravascular space but not into the intracellular space. Based on this fluid shift, the nurse will expect the patient to demonstrate:

A. Hypertension
B. Bradycardia
C. Hypervolemia
D. Hypovolemia

Correct answer: D

Rationale: In the scenario of third-spacing fluid shift, where fluid moves out of the intravascular space but not into the intracellular space, the patient is expected to demonstrate hypovolemia. Hypertension (Choice A) is unlikely as hypovolemia typically leads to decreased blood pressure. Bradycardia (Choice B) is not a common manifestation of hypovolemia, as the body often tries to compensate by increasing heart rate. Hypervolemia (Choice C) indicates an excess of fluid, which is the opposite of what occurs in third spacing.

4. A patient who is hospitalized with a possible electrolyte imbalance is disoriented and weak, has an irregular pulse, and takes hydrochlorothiazide. He most likely suffers from:

A. Hypernatremia
B. Hyponatremia
C. Hyperkalemia
D. Hypokalemia

Correct answer: D

Rationale: The patient is displaying symptoms of hypokalemia, including weakness, disorientation, irregular pulse, which can lead to cardiac disturbances. Hydrochlorothiazide is a potassium-wasting diuretic that can cause hypokalemia if not accompanied by potassium replacement therapy. Hypernatremia (choice A) is characterized by high sodium levels, not potassium. Hyponatremia (choice B) is low sodium levels. Hyperkalemia (choice C) is high potassium levels, which is not consistent with the symptoms described in the question.