Which of the following is NOT a chemical buffering system found within the body?

Correct Answer: B

Rationale: The correct answer is B: phospholipid buffering system. Phospholipids are not involved in buffering pH in the body. The other options (A: haemoglobin, C: phosphate, D: protein) are all known chemical buffering systems within the body. Haemoglobin acts as a buffer by binding to and releasing hydrogen ions, phosphate buffering system helps maintain pH balance in the intracellular and extracellular fluids, and proteins like albumin and histidine residues in proteins can act as buffers by accepting or donating protons to regulate pH levels. Therefore, phospholipids do not play a role in chemical buffering systems in the body, making option B the correct answer.

Correct Answer: C

Rationale: Rationale for Correct Answer (C): 1. Chemical buffers work quickly but may not be sufficient for rapid or large pH changes. 2. Kidneys can regulate acid-base balance by adjusting excretion of H+ and HCO3-. 3. Kidneys can respond immediately to maintain acid-base homeostasis. 4. Therefore, kidneys participate in acid-base balance to provide a rapid and effective response. Summary of Incorrect Choices: A. Incorrect because chemical buffers can act throughout the body, including the ECF around the kidneys. B. Incorrect because chemical buffers can buffer against various pH changes, not just those from increased HCO3-. D. Incorrect because chemical buffers can also bind to other ions, not just H+, and kidneys do not remove H+ entirely from the body.

Correct Answer: A

Rationale: The correct answer is A: uncompensated metabolic acidosis. The ratio of [HCO3-] / [CO2] is typically around 20/1 in the blood (normal range). In this case, the ratio is 40/1, indicating an increase in [HCO3-] relative to [CO2]. This suggests metabolic alkalosis. However, if the ratio is inverted (as in this case), it indicates compensation for a primary respiratory alkalosis. This leads to a primary metabolic acidosis. Therefore, the correct interpretation is uncompensated metabolic acidosis. Choices B, C, and D are incorrect as they do not consider the specific relationship between [HCO3-] and [CO2].

Correct Answer: B

Rationale: Rationale: The correct answer is B because the serum anionic gap is a valuable tool in diagnosing the cause of metabolic acidosis. By calculating the anion gap (serum sodium - (serum chloride + serum bicarbonate)), clinicians can identify unmeasured anions such as lactate or ketones, which are often elevated in metabolic acidosis. This information helps differentiate between various causes of metabolic acidosis, such as lactic acidosis or ketoacidosis. Summary: A: Incorrect. The serum anionic gap is not typically used to diagnose the cause of metabolic alkalosis. C: Incorrect. The serum anionic gap is not typically used to diagnose the cause of respiratory alkalosis. D: Incorrect. The serum anionic gap is not typically used to diagnose the cause of respiratory acidosis.

Correct Answer: B

Rationale: Certainly! The correct answer is B: FALSE. This statement is incorrect because in real-world systems, the output of a substance is not always matched equally with its input due to factors such as losses, inefficiencies, and transformations. Therefore, it is not always true that input equals output. Choices A, C, and D are incorrect because they do not accurately reflect the variability and discrepancies that can occur between input and output in systems.