ATI RN
Chapter 14 Nutrition and Fluid Balance Answer Key Questions
Question 1 of 5
Cells in a hypertonic ECF tend to lose water by osmosis.
Correct Answer: A
Rationale: Step 1: In a hypertonic extracellular fluid (ECF), there is a higher solute concentration outside the cell. Step 2: Due to osmosis, water will move from an area of low solute concentration (inside the cell) to high solute concentration (outside the cell). Step 3: As a result, cells in a hypertonic ECF tend to lose water to balance the solute concentration. Step 4: Therefore, the statement "Cells in a hypertonic ECF tend to lose water by osmosis" is true. Summary: Choice A is correct because water moves out of the cell in a hypertonic environment. Choices B, C, and D are incorrect as they do not provide a logical explanation based on osmosis principles.
Question 2 of 5
Only the H+ ions that are free in solution will contribute to the pH of that solution.
Correct Answer: A
Rationale: Step 1: pH is a measure of the concentration of H+ ions in a solution. Step 2: Only free H+ ions can interact with water molecules to affect pH. Step 3: Bound H+ ions in compounds do not directly impact pH. Step 4: Therefore, only free H+ ions contribute to the pH of a solution. Step 5: Thus, the statement that only free H+ ions contribute to pH is TRUE. Other choices are incorrect as they do not provide a logical explanation for the concept.
Question 3 of 5
Acidosis causes the kidneys to excrete more H+, which reduces the amount of K+ secreted, causing K+ retention.
Correct Answer: A
Rationale: Step 1: Acidosis leads to increased H+ excretion by the kidneys to help regulate blood pH. Step 2: In response to increased H+ excretion, there is a decrease in the excretion of K+ ions. Step 3: Reduced K+ excretion leads to K+ retention in the body. Therefore, the correct answer is A (TRUE). Acidosis does indeed cause the kidneys to excrete more H+, which in turn reduces the amount of K+ secreted, resulting in K+ retention. Option B is incorrect because it contradicts the physiological relationship between acidosis, H+ excretion, and K+ retention. Options C and D are not applicable as they are placeholders.
Question 4 of 5
If metabolic acidosis is caused by a pulmonary disease, the respiratory system will not be capable of acting as a buffering system.
Correct Answer: A
Rationale: Step 1: Metabolic acidosis results from an increase in acid levels in the body due to a non-respiratory cause. Step 2: If metabolic acidosis is caused by a pulmonary disease, it implies that the respiratory system is already compromised. Step 3: When the respiratory system is affected by a pulmonary disease, its ability to buffer the acid-base imbalance is diminished. Step 4: Therefore, if metabolic acidosis is caused by a pulmonary disease, the respiratory system cannot effectively act as a buffering system. Summary: Choice A is correct because when a pulmonary disease causes metabolic acidosis, the respiratory system's buffering capacity is impaired. Choices B, C, and D are incorrect as they do not explain the relationship between pulmonary disease and metabolic acidosis.
Question 5 of 5
The kidneys are the first line of defence against changes in acid-base balance because they are the most powerful mechanism for maintaining pH.
Correct Answer: B
Rationale: The correct answer is B: FALSE. The kidneys are not the first line of defense against changes in acid-base balance; they are the second line of defense. The first line of defense is the buffer systems in the body, which include bicarbonate, phosphate, and proteins. These buffer systems act quickly to prevent drastic changes in pH. The kidneys come into play as a slower but more powerful mechanism for maintaining pH by regulating the excretion or retention of hydrogen ions and bicarbonate ions. Therefore, while the kidneys are crucial in long-term regulation of acid-base balance, they are not the first line of defense.