ATI RN
ATI Fluid and Electrolytes
1. Which positive ion is most prevalent in intracellular fluid?
- A. Calcium
- B. Potassium
- C. Sodium
- D. Magnesium
Correct answer: B
Rationale: The correct answer is Potassium (K+). Potassium is the predominant cation found within cells, making it the most prevalent positive ion in intracellular fluid. Calcium, sodium, and magnesium are also essential ions in the body, but they are not as abundant in intracellular fluid. Calcium is vital for bone health and muscle function, sodium helps in maintaining fluid balance and nerve function, and magnesium is involved in numerous biochemical reactions.
2. When does dehydration begin to occur?
- A. the body reduces fluid output to zero.
- B. the body increases the release of ANH.
- C. the salivary secretions decrease.
- D. the salivary secretions increase.
Correct answer: C
Rationale: Dehydration leads to a decrease in the body's fluid levels, causing the salivary glands to produce less saliva, resulting in a dry mouth. Therefore, when dehydration begins to occur, salivary secretions decrease. Choice A is incorrect because the body does not reduce fluid output to zero during dehydration; it tries to conserve fluids. Choice B is incorrect as dehydration does not directly increase the release of ANH (Atrial Natriuretic Hormone). Choice D is incorrect because salivary secretions do not increase but decrease during dehydration.
3. Where is the largest volume of water in the body located?
- A. Plasma
- B. The fluid inside the cells
- C. Interstitial fluid
- D. Lymph
Correct answer: B
Rationale: The correct answer is B. The largest volume of water in the body is found inside the cells, known as intracellular fluid. This fluid makes up the majority of the body's total water content. Choices A, C, and D are incorrect because while plasma, interstitial fluid, and lymph are important components of the body's fluid compartments, they do not contain the largest volume of water in the body.
4. Which negative ion is most abundant in blood plasma?
- A. Bicarbonate
- B. Chloride
- C. Hydroxide
- D. Phosphate
Correct answer: B
Rationale: Chloride (Cl-) is the most abundant anion in blood plasma. It plays a crucial role in maintaining osmotic balance and acid-base homeostasis. Bicarbonate (Choice A) is important for buffering acids in the body but is not the most abundant negative ion in blood plasma. Hydroxide (Choice C) is not typically found in high concentrations in blood plasma. Phosphate (Choice D) is an important anion in the body but is not as abundant as chloride in blood plasma.
5. Electrolytes:
- A. do not form when glucose is added to water.
- B. dissociate in water solutions, but do not form ions.
- C. form ions in water solutions, but do not necessarily dissociate.
- D. dissociate in water solutions and form ions in water solutions.
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.
Similar Questions

Access More Features
ATI RN Basic
$69.99/ 30 days
- 50,000 Questions with answers
- All ATI courses Coverage
- 30 days access @ $69.99
ATI RN Premium
$149.99/ 90 days
- 50,000 Questions with answers
- All ATI courses Coverage
- 30 days access @ $149.99