When does the amount of H+ generated from CO increase?

Correct Answer: D

Rationale: The correct answer is D because when the rate of CO removal by the lungs is less than the rate of CO production by the tissues, more CO builds up in the body. This excess CO leads to increased generation of H+ ions due to the breakdown of CO into H+ ions and carbon. This acidic environment from the increased H+ ions can disrupt the body's pH balance. Choice A is incorrect because the rate of protein catabolism and anabolism does not directly impact the generation of H+ from CO. Choice B is also incorrect because the speed of protein breakdown and synthesis does not affect the generation of H+ from CO. Choice C is incorrect because the rate of CO removal by the lungs being higher than CO production does not lead to an increase in H+ generation.

Correct Answer: A

Rationale: Step 1: The respiratory system can react to changes in pH quickly due to its ability to modify the rate and depth of breathing. Step 2: By increasing the rate and depth of breathing, excess CO2 is expelled, reducing H+ concentration and restoring pH balance. Step 3: This rapid response allows the respiratory system to buffer against pH changes within seconds. Step 4: Choice A is correct as it accurately describes the buffering activities of the respiratory system. Summary: Choice B is incorrect because an increase in pH would lead to a decrease in H+ concentration, triggering an increase in the depth and rate of breathing. Choice C is incorrect as the respiratory system can buffer against both increases and decreases in arterial [H+]. Choice D is incorrect as the respiratory system can counteract changes in pH from both respiratory and nonrespiratory causes.

Correct Answer: D

Rationale: Buffering of urine is important to prevent acidosis because if urine becomes too acidic, it prevents tubular secretion of H+ ions, limiting the renal buffering capacity. This helps maintain the body's acid-base balance. Choices A, B, and C are incorrect because they do not directly relate to the role of buffering urine in preventing acidosis. Choice A is incorrect because bicarbonate secretion is a mechanism to counteract acidosis, not a reason for buffering urine. Choice B is incorrect as acidic urine does not directly inhibit the micturition reflex. Choice C is incorrect because acidic urine does not typically damage the urinary bladder.

Correct Answer: C

Rationale: Step-by-step rationale: 1. Vomiting leads to loss of fluids and electrolytes, causing dehydration. 2. Loss of stomach acid (HCl) during vomiting can result in metabolic alkalosis. 3. Dehydration leads to increased concentration of HCO3- in the blood, causing metabolic acidosis. 4. Therefore, vomiting can lead to dehydration and metabolic acidosis (Choice C). Summary: - Choice A is incorrect as vomiting leads to loss of H+ ions, not abnormal buildup. - Choice B is incorrect as vomiting does not lead to a decrease in HCO3-. - Choice D is incorrect as vomiting typically leads to metabolic acidosis, not alkalosis.

Correct Answer: B

Rationale: The correct answer is B because faster, deeper respirations help to eliminate excess CO2, which reduces the concentration of H+ ions in the blood, thus increasing pH. This compensates for the change in [H+] and helps maintain pH balance. Slower, shallower respirations (choice C) would not effectively eliminate CO2, leading to a buildup of H+ ions and a decrease in pH. Slower, deeper respirations (choice D) would also not effectively eliminate CO2, and the depth of respiration alone does not directly impact pH regulation. Choice A is incorrect because the respiratory mechanism plays a crucial role in pH control through the elimination of CO2.