Which substance dissociates into ions in a water solution?

Correct Answer: D

Rationale: The correct answer is 'Electrolyte.' Electrolytes are substances that dissociate into ions when dissolved in water. Intracellular fluid, interstitial fluid, and plasma are not substances that dissociate into ions in a water solution. Intracellular fluid is the fluid inside cells, interstitial fluid is the fluid between cells, and plasma is the liquid component of blood. These choices do not dissociate into ions in a water solution, unlike electrolytes.

Correct Answer: D

Rationale: The correct answer is D. Electrolytes are substances that dissociate into ions when dissolved in water, allowing the solution to conduct electricity. Choice A is incorrect because glucose does not form electrolytes when added to water. Choice B is incorrect as it states that electrolytes dissociate but do not form ions, which is inaccurate as electrolytes do form ions in water solutions. Choice C is also incorrect as it states that electrolytes form ions but may not necessarily dissociate, which goes against the definition of electrolytes that must dissociate into ions for conductivity. Therefore, choice D is the most accurate as it correctly describes that electrolytes dissociate in water solutions and form ions, highlighting the essential characteristics of electrolytes.

Correct Answer: A

Rationale: An increase in capillary blood pressure leads to a higher force pushing fluid out of the capillaries into the interstitial space, thereby increasing interstitial fluid volume. Choice B is incorrect because capillary blood pressure affects the movement of fluid into the interstitial space, not into the plasma. Choice C is incorrect as an increase in capillary blood pressure would not decrease interstitial fluid volume. Choice D is incorrect as it combines contradictory effects when capillary blood pressure increases.

Correct Answer: A

Rationale: The correct answer is A: Kidneys. The kidneys play a crucial role in regulating the amount of sodium in the body. They achieve this by filtering blood and controlling the excretion or reabsorption of sodium. The small intestine is primarily responsible for nutrient absorption, not sodium regulation. The large intestine is mainly involved in water absorption and waste elimination, not sodium balance. The skin helps regulate body temperature through sweating and does not directly regulate sodium levels.

Correct Answer: D

Rationale: The correct answer is D. All the listed organs (lungs, skin, and intestines) contribute to fluid loss from the body. Lungs contribute to fluid loss through respiration, skin through sweating, and intestines through excretion. Therefore, none of the organs listed in the options retain fluids within the body. Choices A, B, and C are incorrect because all of these organs play a role in fluid output from the body.

Correct Answer: D

Rationale: The correct answer is D. Cerebrospinal fluid and the humors of the eye are not considered extracellular fluids. Extracellular fluids are fluids found outside the cells, such as interstitial fluid and lymph. Cerebrospinal fluid is found within the central nervous system, while the humors of the eye (aqueous humor and vitreous humor) are located within the eyeball, making them distinct from extracellular fluids.

Correct Answer: B

Rationale: When selecting a site for IV insertion on the hand or arm, it is important to consider the potential effects on the patient's mobility. The chosen site should not interfere with the patient's movement. Instructing the patient to hold his arm in a dependent position helps increase blood flow, aiding in vein visualization and insertion. It is advisable to choose a site with minimal hair if possible for better adhesion of the dressing. Removing the tourniquet after 2 minutes is recommended to prevent complications like hemoconcentration and potential vein damage. Therefore, option B is the correct choice as it aligns with best practices for IV insertion.

Correct Answer: D

Rationale: Specific gravity is a test used to determine the concentration of solutes in the urine, reflecting the kidney's ability to concentrate urine. Changes in specific gravity can indicate fluid volume status, such as dehydration (fluid volume deficit) or overhydration (fluid volume excess). Options A, B, and C are incorrect as specific gravity does not directly detect nutritional deficits, hyperkalemia, or hypercalcemia.

Correct Answer: B

Rationale: The correct answer is interstitial fluid. Interstitial fluid is the fluid that surrounds and fills the spaces between cells, facilitating nutrient and waste exchange. Plasma, referred to in choice A, is the liquid part of blood. Choice C, intracellular fluid, is the fluid inside cells. Choice D, edema, is an abnormal accumulation of fluid in interstitial spaces, causing swelling.