Give me MCQ 30 questions based on the files above and the answers give me at the end of 30 questions
Reading File
Running Command
python3 << 'EOF' import pdfplumber files = { "L14_Lungs_AcidBase": "/tmp/workspace/attachments/d8e195b8-1a27-4ca2-9409-4654cf9c1a90/MBBS B31 MRES L14 Role Lungs in Regultion of Acid Base.pdf", "Lec22_Biochem_Resp": "/tmp/workspace/attachments/d8e195b8-1a27-4ca2-9409-4654cf9c1a90/Lec 22 Biochemical basis of resp dis.pdf", "Lec15_Regulation_pH2": "/tmp/workspace/attachments/d8e195b8-1a27-4ca2-9409-4654cf9c1a90/Lec 15 Regulation of pH- 2 .pdf" } for name, path in files.items(): print(f"\n{'='*60}") print(f"FILE: {name}") print('='*60) with pdfplumber.open(path) as pdf: print(f"Pages: {len(pdf.pages)}") for i, page in enumerate(pdf.pages): text = page.extract_text() if text: print(f"\n--- Page {i+1} ---") print(text[:3000]) EOF
I have all the content I need. Here are 30 MCQs based on all three lecture files:
30 MCQ Questions - Acid-Base Regulation & Respiratory Biochemistry
Q1. What is the normal arterial blood pH range?
- A) 7.25 – 7.35
- B) 7.35 – 7.45
- C) 7.45 – 7.55
- D) 7.30 – 7.40
Q2. What percentage of CO₂ is transported in the blood as bicarbonate ions?
- A) 7%
- B) 23%
- C) 50%
- D) 70%
Q3. What percentage of CO₂ is transported bound to hemoglobin?
- A) 7%
- B) 23%
- C) 45%
- D) 70%
Q4. Which enzyme catalyzes the conversion of CO₂ and H₂O to carbonic acid (H₂CO₃)?
- A) Lactate dehydrogenase
- B) Carbonic anhydrase
- C) Isocitrate dehydrogenase
- D) Phosphogluconate dehydrogenase
Q5. How quickly does the lung compensation for acid-base imbalance begin?
- A) Within 10–20 seconds
- B) Within 1–3 minutes
- C) Within 1–2 hours
- D) Within 24–48 hours
Q6. In the Henderson-Hasselbalch equation applied to blood pH, what is the pKa value used for carbonic acid?
- A) 5.1
- B) 6.1
- C) 7.1
- D) 8.1
Q7. What is the solubility coefficient of CO₂ in blood plasma used in the Henderson-Hasselbalch equation?
- A) 0.01
- B) 0.03
- C) 0.3
- D) 3.0
Q8. The respiratory mechanism for pH regulation is considered which line of defense?
- A) First
- B) Second
- C) Third
- D) Fourth
Q9. In respiratory acidosis, what is the primary change in blood values?
- A) Decreased pCO₂
- B) Increased HCO₃⁻
- C) Increased pCO₂ (> 45 mmHg)
- D) Decreased H⁺ concentration
Q10. Hyperventilation causing excessive blow-off of CO₂ leads to which acid-base disorder?
- A) Respiratory acidosis
- B) Metabolic acidosis
- C) Respiratory alkalosis
- D) Metabolic alkalosis
Q11. Which of the following is NOT a cause of respiratory acidosis?
- A) Emphysema
- B) Opioid overdose
- C) Anxiety
- D) Pneumonia
Q12. Which metabolic pathway is the LARGEST producer of CO₂ inside the mitochondria?
- A) Glycolysis
- B) Pentose Phosphate Pathway
- C) Citric Acid Cycle
- D) Beta-oxidation
Q13. How many molecules of CO₂ are produced from one molecule of glucose through complete aerobic respiration?
- A) 2
- B) 4
- C) 6
- D) 8
Q14. What is the normal reference range for total carbon dioxide (ctCO₂) in arterial blood?
- A) 10–15 mEq/L
- B) 18–22 mEq/L
- C) 23–29 mEq/L
- D) 35–45 mEq/L
Q15. In metabolic acidosis, which compensatory respiratory change occurs?
- A) Hypoventilation to retain CO₂
- B) Hyperventilation to expel CO₂
- C) No respiratory change
- D) Increased pCO₂
Q16. In the "chloride shift," HCO₃⁻ diffuses out of the red blood cell in exchange for which ion?
- A) Na⁺
- B) K⁺
- C) Cl⁻
- D) Ca²⁺
Q17. Which of the following conditions is associated with metabolic alkalosis?
- A) Diarrhea
- B) Excess vomiting
- C) Renal failure
- D) Diabetic ketoacidosis
Q18. The anion gap formula is:
- A) Na⁺ + K⁺ − (Cl⁻ + HCO₃⁻)
- B) Na⁺ − (Cl⁻ + HCO₃⁻)
- C) Na⁺ − Cl⁻
- D) HCO₃⁻ − Cl⁻
Q19. What is the normal anion gap range?
- A) 5 ± 2 mmol/L
- B) 8 ± 2 mmol/L
- C) 12 ± 2 mmol/L
- D) 20 ± 2 mmol/L
Q20. In chronic respiratory acidosis, what is the expected rise in bicarbonate per 10 mmHg rise in pCO₂?
- A) 1 mmol/L
- B) 2 mmol/L
- C) 3.5 mmol/L
- D) 5 mmol/L
Q21. Cystic fibrosis (CF) is caused by a mutation in which gene?
- A) BRCA1
- B) CFTR
- C) TP53
- D) APC
Q22. Cystic fibrosis is inherited in which pattern?
- A) Autosomal dominant
- B) X-linked recessive
- C) Autosomal recessive
- D) Mitochondrial inheritance
Q23. The CFTR protein is located on which chromosome?
- A) Chromosome 4
- B) Chromosome 7
- C) Chromosome 11
- D) Chromosome 17
Q24. Which of the following best describes the role of alpha-1 antitrypsin in the lung?
- A) It stimulates neutrophil activity
- B) It inhibits protease enzymes like elastase
- C) It produces surfactant
- D) It transports CO₂ to the lungs
Q25. In emphysema, smoking leads to increased levels of which enzyme that destroys alveolar walls?
- A) Carbonic anhydrase
- B) Lactase
- C) Neutrophil elastase
- D) Amylase
Q26. Pulmonary surfactant is primarily secreted by which cells?
- A) Type I alveolar cells
- B) Type II alveolar cells
- C) Goblet cells
- D) Clara cells
Q27. What is the main lipid component of pulmonary surfactant that reduces surface tension?
- A) Cholesterol
- B) Sphingomyelin
- C) Dipalmitoyl phosphatidylcholine (DPPC)
- D) Phosphatidylserine
Q28. Leukotrienes are produced from arachidonic acid via which enzyme?
- A) Cyclooxygenase (COX)
- B) 5-Lipoxygenase
- C) Phospholipase A₂
- D) Thromboxane synthase
Q29. LTB₄ (Leukotriene B₄) acts primarily as which type of mediator in COPD?
- A) Bronchodilator
- B) Surfactant stimulator
- C) Potent neutrophil chemoattractant
- D) Antiprotease activator
Q30. Which of the following is a simple initial treatment for respiratory alkalosis due to hyperventilation?
- A) Administer IV sodium bicarbonate
- B) Breathe into a paper bag
- C) Administer supplemental oxygen
- D) Perform chest physiotherapy
ANSWERS
| Q | Answer | Explanation |
|---|---|---|
| 1 | B | Normal arterial blood pH is 7.35–7.45 |
| 2 | D | 70% of CO₂ is transported as bicarbonate |
| 3 | B | 23% is transported bound to hemoglobin |
| 4 | B | Carbonic anhydrase drives CO₂ + H₂O ⇌ H₂CO₃ |
| 5 | B | Lung compensation begins within 1–3 minutes |
| 6 | B | pKa of carbonic acid in blood at 37°C = 6.1 |
| 7 | B | Solubility coefficient of CO₂ = 0.03 |
| 8 | B | Respiratory mechanism is the 2nd line of defense |
| 9 | C | Respiratory acidosis = pCO₂ > 45 mmHg |
| 10 | C | Hyperventilation blows off CO₂ → respiratory alkalosis |
| 11 | C | Anxiety causes respiratory alkalosis, not acidosis |
| 12 | C | Citric Acid Cycle is the largest producer of CO₂ |
| 13 | C | Complete oxidation of glucose produces 6 CO₂ |
| 14 | C | Normal ctCO₂ = 23–29 mEq/L |
| 15 | B | Metabolic acidosis is compensated by hyperventilation |
| 16 | C | Chloride shift: HCO₃⁻ exits RBC in exchange for Cl⁻ |
| 17 | B | Vomiting causes loss of HCl → metabolic alkalosis |
| 18 | B | AG = Na⁺ − (Cl⁻ + HCO₃⁻) |
| 19 | C | Normal anion gap = 12 ± 2 mmol/L |
| 20 | C | Chronic resp. acidosis: HCO₃⁻ rises 3.5 mmol/L per 10 mmHg pCO₂ rise |
| 21 | B | CF is caused by mutation in the CFTR gene |
| 22 | C | CF is autosomal recessive |
| 23 | B | CFTR gene is on chromosome 7 |
| 24 | B | Alpha-1 antitrypsin inhibits elastase/proteases |
| 25 | C | Smoking increases neutrophil elastase → alveolar destruction |
| 26 | B | Surfactant is secreted by Type II alveolar cells |
| 27 | C | DPPC (dipalmitoyl phosphatidylcholine) is the main surfactant lipid |
| 28 | B | Leukotrienes are produced via 5-lipoxygenase |
| 29 | C | LTB₄ is a potent neutrophil chemoattractant |
| 30 | B | Breathing into a paper bag re-inhales CO₂ to correct alkalosis |
Give me 30 mcq questions based on the learning outcomes based on the files above and the answers give me at the end of question
I already have all the content from the three PDFs in my context. Let me generate 30 MCQs tightly mapped to the learning outcomes from each file.
30 MCQ Questions Based on Learning Outcomes
From L14 - Role of Lungs in Acid-Base Regulation
LO: Summarize acid-base balance in pH regulation | Describe lung regulation | Describe respiratory acid-base imbalances | Explain respiratory defence mechanisms
Q1. Which of the following BEST summarizes how the lungs regulate acid-base balance?
- A) By filtering fixed acids through the alveolar membrane
- B) By controlling the elimination of carbon dioxide (CO₂)
- C) By secreting bicarbonate directly into the bloodstream
- D) By producing carbonic anhydrase into the plasma
Q2. CO₂ is classified as a "volatile acid" because:
- A) It is produced only during anaerobic metabolism
- B) It combines with water to form carbonic acid and can be exhaled
- C) It directly releases H⁺ without involving water
- D) It is excreted only by the kidneys
Q3. When blood pH falls (acidosis), the chemoreceptors trigger which response?
- A) Hypoventilation to retain CO₂
- B) Hyperventilation to blow off excess CO₂
- C) Decreased depth of breathing to conserve acid
- D) Renal excretion of bicarbonate
Q4. When blood becomes too alkaline, the lungs respond by:
- A) Increasing the rate and depth of ventilation
- B) Slowing and shallowing breathing to retain CO₂
- C) Increasing CO₂ exhalation to lower pH further
- D) Activating carbonic anhydrase in plasma
Q5. According to Le Chatelier's Principle applied to blood pH: when the lungs exhale more CO₂, the equation shifts LEFT. What is the result?
- A) More H⁺ ions are released, dropping pH
- B) Free H⁺ ions are consumed and blood pH rises
- C) Bicarbonate is destroyed, lowering pH
- D) Carbonic anhydrase is inhibited
Q6. The respiratory centre that controls rate and depth of ventilation is located in which structure?
- A) Cerebellum
- B) Hypothalamus
- C) Medulla oblongata
- D) Cerebral cortex
Q7. Respiratory mechanism for pH regulation depends on two factors. Which of the following is one of them?
- A) Sensitivity of the liver to changes in plasma bicarbonate
- B) Ready diffusibility of CO₂ across the pulmonary alveolar membrane
- C) Renal production of ammonia in response to acidosis
- D) The concentration of hemoglobin in red blood cells
Q8. Which of the following is a PRIMARY metabolic pathway that produces CO₂?
- A) Glycolysis (in the cytoplasm)
- B) Urea cycle (in the liver)
- C) Citric Acid Cycle (in the mitochondrial matrix)
- D) Fatty acid synthesis (in the endoplasmic reticulum)
Q9. The respiratory defence mechanism for acid-base balance is described as a "coarse" mechanism because it:
- A) Takes several days to act
- B) Can eliminate all types of fixed acids
- C) Cannot eliminate fixed acids like sulfuric or lactic acid
- D) Works only in alkalosis, not acidosis
Q10. Which of the following correctly lists the three lines of defense for pH regulation in the correct order?
- A) Respiratory → Renal → Chemical buffers
- B) Renal → Respiratory → Chemical buffers
- C) Chemical buffers → Respiratory → Renal
- D) Chemical buffers → Renal → Respiratory
Q11. In the bicarbonate buffer system, which enzyme drives the reversible conversion between CO₂/H₂O and carbonic acid in red blood cells?
- A) Lactate dehydrogenase
- B) Carbonic anhydrase
- C) Phosphogluconate dehydrogenase
- D) Alpha-ketoglutarate dehydrogenase
Q12. During the sequence of events in tissues, deoxygenated hemoglobin (HHb) acts as an anion and accepts H⁺ ions. Where does HCO₃⁻ go?
- A) It stays inside the red blood cell
- B) It diffuses into plasma in exchange for Cl⁻ (chloride shift)
- C) It binds directly to hemoglobin
- D) It is excreted immediately into urine
Q13. In respiratory acidosis, the kidneys compensate by:
- A) Excreting bicarbonate and retaining H⁺
- B) Activating carbonic anhydrase to generate more HCO₃⁻ and excrete more H⁺
- C) Reducing ammonia production
- D) Retaining CO₂ to balance pH
Q14. Respiratory alkalosis is primarily caused by:
- A) Hypoventilation and CO₂ retention
- B) Excess bicarbonate ingestion
- C) Hyperventilation causing excessive loss of CO₂
- D) Renal failure causing bicarbonate accumulation
Q15. Using the Henderson-Hasselbalch equation: pH = 6.1 + log [HCO₃⁻] / (0.03 × PaCO₂). What does the value "0.03" represent?
- A) The pKa of bicarbonate
- B) The normal bicarbonate concentration in blood
- C) The solubility coefficient of CO₂ in blood plasma
- D) The ratio of carbonic acid to bicarbonate at normal pH
From Lec 15 - Regulation of pH Part 2
LO: Describe acid-base disorders | Classify compensation | Interpret ABG findings
Q16. Which ABG value confirms a diagnosis of metabolic acidosis?
- A) HCO₃⁻ > 33 mmol/L
- B) pCO₂ > 45 mmHg
- C) HCO₃⁻ < 22 mmol/L
- D) pH > 7.45
Q17. In respiratory alkalosis, the PRIMARY change is:
- A) Excess of H₂CO₃ (carbonic acid)
- B) Deficit of HCO₃⁻ (bicarbonate)
- C) Deficit of H₂CO₃ (carbonic acid)
- D) Excess of HCO₃⁻ (bicarbonate)
Q18. A patient has pH 7.28, pCO₂ 55 mmHg, HCO₃⁻ 25 mmol/L. What is the PRIMARY disturbance?
- A) Metabolic acidosis
- B) Metabolic alkalosis
- C) Respiratory acidosis
- D) Respiratory alkalosis
Q19. In metabolic acidosis, what is the expected respiratory compensation per 1 mmol/L drop in bicarbonate?
- A) pCO₂ increases by 1 mmHg
- B) pCO₂ decreases by 1 mmHg
- C) pCO₂ increases by 0.6 mmHg
- D) pCO₂ decreases by 0.6 mmHg
Q20. Which statement about compensatory responses is TRUE?
- A) Compensation fully corrects the primary acid-base disturbance
- B) The compensatory change is always in the opposite direction to the primary disturbance
- C) Compensation tries to restore pH but cannot fully correct the disturbance
- D) Compensation occurs only through renal mechanisms
Q21. In metabolic alkalosis, the secondary (compensatory) change in pCO₂ is:
- A) Decreased pCO₂ due to hyperventilation
- B) Unchanged pCO₂
- C) Increased pCO₂ due to hypoventilation
- D) Increased pCO₂ due to increased CO₂ production
Q22. A patient presenting with severe diarrhea develops which acid-base disturbance?
- A) Respiratory alkalosis (loss of CO₂)
- B) Metabolic alkalosis (loss of HCl)
- C) Metabolic acidosis (loss of bicarbonate)
- D) Respiratory acidosis (CO₂ retention)
Q23. Arterial blood gas (ABG) analysis is performed using blood drawn from which artery?
- A) Femoral artery
- B) Brachial artery
- C) Radial artery
- D) Carotid artery
Q24. In compensation for metabolic alkalosis, why is respiratory compensation limited?
- A) The kidneys work faster than the lungs
- B) Hypoventilation is limited by the onset of hypoxia
- C) Carbonic anhydrase is inhibited during alkalosis
- D) The bicarbonate buffer system is saturated
Q25. An elevated anion gap (> 14 mmol/L) in a patient with low pH and low bicarbonate most likely indicates:
- A) Respiratory acidosis from CO₂ retention
- B) High anion gap metabolic acidosis (e.g., from lactic acid or ketones)
- C) Metabolic alkalosis from excess vomiting
- D) Respiratory alkalosis from hyperventilation
From Lec 22 - Biochemical Basis of Respiratory Diseases
LO: Emphysema | Cystic fibrosis | ROS | Surfactant | Leukotrienes/Prostaglandins
Q26. The protease-antiprotease theory of emphysema states that destruction of alveolar walls occurs due to:
- A) Excess surfactant production overwhelming alveolar stability
- B) An imbalance where proteases (like elastase) overwhelm antiproteases (like alpha-1 antitrypsin)
- C) Excessive mucus production blocking airflow and causing air trapping
- D) Deficiency of leukotrienes causing reduced inflammatory protection
Q27. Patients with panacinar emphysema may lack which specific antiprotease?
- A) Cystatin C
- B) TIMP (tissue inhibitor of metalloproteases)
- C) Alpha-1 antitrypsin
- D) Alpha-2 macroglobulin
Q28. In cystic fibrosis, the molecular defect leads to which characteristic diagnostic feature?
- A) Elevated serum alpha-1 antitrypsin levels
- B) Elevated chloride concentration in sweat (salty sweat)
- C) Decreased mucus viscosity in the lungs
- D) Reduced neutrophil count in sputum
Q29. Which of the following BEST describes the role of pulmonary surfactant in the alveolus?
- A) It increases surface tension to keep alveoli rigid during inspiration
- B) It reduces surface tension at the alveolar air-liquid interface, preventing alveolar collapse
- C) It transports oxygen from the alveolus into the capillary blood
- D) It activates macrophages to phagocytose bacteria in the airways
Q30. Leukotrienes are produced from arachidonic acid by 5-lipoxygenase. In respiratory diseases, cysteinyl leukotrienes (cys-LTs) are particularly important because they cause:
- A) Vasodilation and reduced mucus secretion
- B) Bronchoconstriction and pro-inflammatory effects
- C) Alveolar surfactant synthesis and lung expansion
- D) Inhibition of neutrophil recruitment to the airways
ANSWERS
| Q | Answer | Key Learning Outcome |
|---|---|---|
| 1 | B | Lungs regulate acid-base by controlling CO₂ elimination |
| 2 | B | CO₂ forms carbonic acid and is exhaled - hence "volatile" |
| 3 | B | Acidosis triggers hyperventilation to blow off CO₂ |
| 4 | B | Alkalosis triggers hypoventilation to retain CO₂ |
| 5 | B | Exhaling CO₂ shifts equation left - H⁺ consumed, pH rises |
| 6 | C | Respiratory centre is in the medulla oblongata |
| 7 | B | Diffusibility of CO₂ across pulmonary alveolar membrane |
| 8 | C | Citric Acid Cycle is the primary CO₂-producing pathway |
| 9 | C | Cannot eliminate fixed acids (sulfuric, lactic, keto acids) |
| 10 | C | Chemical buffers → Respiratory → Renal (1st, 2nd, 3rd) |
| 11 | B | Carbonic anhydrase in RBC (can increase rate up to 1 million-fold) |
| 12 | B | HCO₃⁻ diffuses into plasma in exchange for Cl⁻ (chloride shift) |
| 13 | B | Kidneys activate CA, generate HCO₃⁻, excrete H⁺ |
| 14 | C | Respiratory alkalosis caused by hyperventilation/CO₂ loss |
| 15 | C | 0.03 = solubility coefficient of CO₂ in blood plasma |
| 16 | C | Metabolic acidosis = HCO₃⁻ < 22 mmol/L |
| 17 | C | Respiratory alkalosis = deficit of H₂CO₃ (carbonic acid) |
| 18 | C | High pCO₂ (55 mmHg) with low pH = respiratory acidosis |
| 19 | B | pCO₂ decreases 1 mmHg per 1 mmol/L drop in HCO₃⁻ |
| 20 | C | Compensation restores pH toward normal but cannot fully correct it |
| 21 | C | Metabolic alkalosis compensated by hypoventilation → increased pCO₂ |
| 22 | C | Diarrhea causes loss of HCO₃⁻ → metabolic acidosis |
| 23 | C | ABG drawn from the radial artery |
| 24 | B | Hypoventilation as compensation is limited by hypoxia |
| 25 | B | High anion gap = unmeasured acids (lactate, ketones) present |
| 26 | B | Imbalance between proteases and antiproteases destroys alveolar walls |
| 27 | C | Alpha-1 antitrypsin deficiency → panacinar emphysema |
| 28 | B | Defective CFTR → Cl⁻ channel loss → salty sweat |
| 29 | B | Surfactant reduces surface tension, prevents alveolar collapse |
| 30 | B | Cysteinyl leukotrienes cause bronchoconstriction and inflammation |
Give me another 30 MCQ questions same as the conditions of above but in this u can add some case based scenario questions
Here are 30 new MCQs based on the same learning outcomes, with case-based scenario questions mixed in:
30 MCQ Questions (with Case-Based Scenarios)
Conceptual Questions
Q1. Which of the following fixed acids CANNOT be eliminated by the respiratory mechanism?
- A) Carbonic acid
- B) Lactic acid
- C) CO₂
- D) H₂CO₃
Q2. The bicarbonate buffer system maintains a HCO₃⁻ to H₂CO₃ ratio of approximately:
- A) 10:1
- B) 15:1
- C) 20:1
- D) 25:1
Q3. Which of the following describes the "retention effect" in respiratory pH regulation?
- A) Exhaling CO₂ raises blood pH by consuming H⁺ ions
- B) Retaining CO₂ shifts the equation right, releasing more H⁺ and dropping pH
- C) Retaining CO₂ increases bicarbonate production by the kidneys
- D) Retaining CO₂ activates chemoreceptors to increase ventilation rate
Q4. How much CO₂ (in molecules) is produced during the pyruvate oxidation step from ONE glucose molecule?
- A) 0
- B) 1
- C) 2
- D) 4
Q5. Carbonic anhydrase in red blood cells can increase the rate of CO₂ conversion to H₂CO₃ by up to:
- A) 1,000-fold
- B) 10,000-fold
- C) 100,000-fold
- D) 1,000,000-fold
Q6. In the sequence of events at the lungs, deoxygenated hemoglobin (HHb) picks up O₂ to form oxyHb. The released H⁺ then combines with HCO₃⁻ to form H₂CO₃, which breaks down to CO₂. How is this CO₂ removed from the body?
- A) Excreted by the kidneys into urine
- B) Eliminated in expired air during breathing
- C) Stored in muscle tissue as lactic acid
- D) Converted back to bicarbonate and retained
Q7. Which of the following is NOT a cause of respiratory alkalosis?
- A) High altitude hypoxia
- B) Severe anxiety
- C) COPD with CO₂ retention
- D) Early salicylate intoxication
Q8. In metabolic alkalosis, which electrolyte disturbance commonly develops as a result of renal compensation?
- A) Hypernatremia
- B) Hypercalcemia
- C) Hypokalemia
- D) Hyperchloremia
Q9. Dissolved CO₂ contributes approximately how much to total CO₂ in arterial plasma?
- A) 0.3 mEq/L
- B) 1.2 mEq/L
- C) 5.0 mEq/L
- D) 12.0 mEq/L
Q10. Which of the following acid-base disturbances has "excess of bicarbonate" as its primary change?
- A) Respiratory acidosis
- B) Respiratory alkalosis
- C) Metabolic acidosis
- D) Metabolic alkalosis
Q11. In chronic respiratory alkalosis, the expected renal compensation is a decrease in bicarbonate of:
- A) 1 mmol/L per 10 mmHg fall in pCO₂
- B) 2 mmol/L per 10 mmHg fall in pCO₂
- C) 4 mmol/L per 10 mmHg fall in pCO₂
- D) 6 mmol/L per 10 mmHg fall in pCO₂
Q12. Alveolar macrophages play a pathogenic role in emphysema by expressing which enzymes?
- A) Carbonic anhydrase and lactate dehydrogenase
- B) Cathepsins and matrix metalloproteases (MMPs)
- C) Lipoxygenase and cyclooxygenase
- D) Surfactant proteins and phospholipases
Q13. The CFTR protein is a glycoprotein consisting of how many amino acids?
- A) 480
- B) 980
- C) 1,480
- D) 2,480
Q14. In ARDS, Reactive Oxygen Species (ROS) cause the principal clinical manifestations primarily through which mechanism?
- A) Destruction of surfactant proteins in alveoli
- B) Endothelial dysfunction and disruption of pulmonary circulation
- C) Inhibition of the protease-antiprotease balance
- D) Direct blockage of the CFTR chloride channel
Q15. Leukotrienes use which type of signaling to communicate with neighboring cells?
- A) Endocrine signaling
- B) Autocrine and paracrine signaling
- C) Synaptic signaling
- D) Gap junction signaling
Case-Based Scenario Questions
Q16. 🩺 A 65-year-old man with a long history of heavy smoking presents with progressive shortness of breath and barrel chest. Spirometry shows reduced FEV1/FVC. His lung biopsy shows permanent enlargement of air spaces with destruction of alveolar walls but NO fibrosis. What is the underlying biochemical mechanism of his condition?
- A) Deficiency of surfactant leading to alveolar collapse
- B) Excess mucus production blocking small airways
- C) Protease-antiprotease imbalance with excess elastase destroying alveolar connective tissue
- D) ROS-mediated endothelial dysfunction causing capillary leak
Q17. 🩺 A 6-month-old infant presents with recurrent chest infections, failure to thrive, and greasy bulky stools. A sweat chloride test shows 85 mmol/L (normal < 40 mmol/L). What is the most likely diagnosis and its inheritance pattern?
- A) Emphysema; autosomal dominant
- B) Cystic fibrosis; autosomal recessive
- C) ARDS; X-linked recessive
- D) Asthma; multifactorial
Q18. 🩺 A 28-year-old woman with bronchial asthma has worsening symptoms despite bronchodilator use. Her sputum analysis reveals elevated concentrations of cysteinyl leukotrienes. Which class of drugs would MOST specifically target this mediator?
- A) Corticosteroids
- B) Beta-2 agonists
- C) Leukotriene antagonists (e.g., montelukast)
- D) Antihistamines
Q19. 🩺 A 45-year-old ICU patient develops sudden respiratory failure after a road traffic accident and smoke inhalation. Chest X-ray shows bilateral infiltrates. ABG reveals severe hypoxia. Bronchoalveolar lavage shows reduced levels of phosphatidylcholine. Which condition is most likely, and what component is deficient?
- A) Emphysema; alpha-1 antitrypsin
- B) ARDS; pulmonary surfactant (DPPC)
- C) Cystic fibrosis; CFTR protein
- D) Respiratory alkalosis; bicarbonate
Q20. 🩺 A 72-year-old COPD patient on home oxygen is brought to the emergency department with altered consciousness. ABG results: pH 7.22, pCO₂ 68 mmHg, HCO₃⁻ 27 mmol/L. What is the acid-base diagnosis?
- A) Acute respiratory alkalosis
- B) Metabolic acidosis with respiratory compensation
- C) Respiratory acidosis with partial renal compensation
- D) Fully compensated metabolic alkalosis
Q21. 🩺 A 19-year-old university student presents to A&E hyperventilating due to a panic attack. Her ABG shows: pH 7.58, pCO₂ 22 mmHg, HCO₃⁻ 20 mmol/L. What is the diagnosis and appropriate first-line management?
- A) Metabolic alkalosis; IV sodium bicarbonate
- B) Respiratory alkalosis; breathe into a paper bag or rebreather mask
- C) Respiratory acidosis; assisted ventilation
- D) Metabolic acidosis; IV lactate solution
Q22. 🩺 A 55-year-old diabetic patient in poor glycaemic control presents with deep, rapid (Kussmaul) breathing, fruity breath odour, and blood glucose of 28 mmol/L. ABG: pH 7.18, pCO₂ 20 mmHg, HCO₃⁻ 8 mmol/L. The deep rapid breathing in this patient represents:
- A) Primary respiratory acidosis
- B) Respiratory compensation for metabolic acidosis
- C) Primary respiratory alkalosis from anxiety
- D) Renal compensation for respiratory alkalosis
Q23. 🩺 A post-operative patient has been vomiting persistently for 2 days. ABG: pH 7.52, pCO₂ 48 mmHg, HCO₃⁻ 38 mmol/L. What is the acid-base disturbance and the most likely cause?
- A) Respiratory acidosis; CO₂ retention from hypoventilation
- B) Metabolic alkalosis; loss of gastric HCl through vomiting
- C) Respiratory alkalosis; hyperventilation from pain
- D) Metabolic acidosis; loss of bicarbonate from diarrhoea
Q24. 🩺 A mountaineer ascending to 5,000 m altitude notices he is breathing faster than normal. His ABG shows pH 7.50, pCO₂ 30 mmHg. The hyperventilation at altitude is stimulated by:
- A) Increased CO₂ levels detected by peripheral chemoreceptors
- B) Hypoxia stimulating peripheral chemoreceptors, causing hyperventilation and CO₂ blow-off
- C) Cold temperature directly activating the medullary respiratory centre
- D) Increased bicarbonate production by the kidneys stimulating breathing
Q25. 🩺 A patient with chronic kidney disease (stage 5) presents with pH 7.29, pCO₂ 30 mmHg, HCO₃⁻ 14 mmol/L, and elevated anion gap of 22 mmol/L. The most likely cause of the elevated anion gap is:
- A) Loss of bicarbonate through diarrhoea (normal anion gap acidosis)
- B) Accumulation of unmeasured anions (phosphates, sulfates, organic acids) due to renal failure
- C) Excess bicarbonate administration causing alkalosis
- D) CO₂ retention from impaired ventilation
Q26. 🩺 A 35-year-old patient with spinal cord injury at C4 level develops progressive respiratory failure requiring ventilator support. His ABG before ventilation: pH 7.26, pCO₂ 60 mmHg, HCO₃⁻ 26 mmol/L. The primary reason for CO₂ retention in this patient is:
- A) Airway obstruction from excess mucus
- B) Neuromuscular failure - inability to activate respiratory muscles due to spinal cord injury
- C) Pulmonary surfactant deficiency causing alveolar collapse
- D) Protease-antiprotease imbalance destroying alveolar walls
Q27. 🩺 A newborn at 28 weeks gestation develops respiratory distress immediately after birth. Chest X-ray shows bilateral ground-glass opacification. The paediatrician administers intratracheal surfactant therapy. The primary lipid component administered to this premature infant is:
- A) Sphingomyelin
- B) Cholesterol esters
- C) Dipalmitoyl phosphatidylcholine (DPPC)
- D) Lysophosphatidic acid
Q28. 🩺 A 50-year-old woman on long-term antacid therapy for peptic ulcer disease presents with weakness, muscle cramps, and tetany. ABG: pH 7.49, HCO₃⁻ 31 mmol/L, pCO₂ 46 mmHg. Her symptoms of tetany and hyperactive reflexes are characteristic features of which condition?
- A) Metabolic acidosis
- B) Respiratory acidosis
- C) Metabolic alkalosis
- D) Respiratory alkalosis
Q29. 🩺 A 40-year-old male heavy smoker undergoes serum alpha-1 antitrypsin testing, which shows severely deficient levels. A pulmonologist explains the consequences. Which of the following BEST explains why this deficiency accelerates emphysema specifically in smokers?
- A) Smoking reduces surfactant production, worsening ventilation
- B) Smoking attracts neutrophils to the lungs AND abnormal antitrypsin polymerises, acting as a chemoattractant - creating a dual increase in neutrophil elastase activity with no antiprotease protection
- C) Smoking directly activates CFTR channels, causing chloride imbalance in airways
- D) Smoking reduces macrophage TIMP production, leaving MMPs unopposed only in non-smokers
Q30. 🩺 A 30-year-old man with no prior lung disease is admitted after a heroin overdose. He is drowsy with a respiratory rate of 6 breaths/min. ABG: pH 7.20, pCO₂ 78 mmHg, HCO₃⁻ 29 mmol/L. What is the acid-base diagnosis and the MOST appropriate initial treatment?
- A) Metabolic acidosis; IV sodium bicarbonate infusion
- B) Respiratory alkalosis; paper bag rebreathing
- C) Acute respiratory acidosis; restore ventilation (naloxone + assisted ventilation if needed)
- D) Chronic respiratory acidosis; diuretics to reduce bicarbonate
ANSWERS
| Q | Answer | Explanation |
|---|---|---|
| 1 | B | Lactic acid is a fixed acid - cannot be exhaled, only renally excreted |
| 2 | C | Normal HCO₃⁻ : H₂CO₃ ratio = 20:1, maintaining pH 7.4 |
| 3 | B | Retaining CO₂ shifts equation right → more H⁺ released → pH drops |
| 4 | C | Pyruvate oxidation produces 2 CO₂ (one per pyruvate, 2 pyruvates per glucose) |
| 5 | D | Carbonic anhydrase increases the reaction rate up to 1,000,000-fold |
| 6 | B | CO₂ is eliminated in expired air through the lungs |
| 7 | C | COPD with CO₂ retention causes respiratory ACIDOSIS, not alkalosis |
| 8 | C | K⁺ exits cells in exchange for H⁺ during alkalosis → hypokalemia |
| 9 | B | Dissolved CO₂ contributes approximately 1.2 mEq/L to arterial plasma |
| 10 | D | Metabolic alkalosis = excess HCO₃⁻ |
| 11 | C | Chronic respiratory alkalosis: HCO₃⁻ decreases 4 mmol/L per 10 mmHg fall in pCO₂ |
| 12 | B | Alveolar macrophages express cathepsins and MMPs in emphysema |
| 13 | C | CFTR protein consists of 1,480 amino acids |
| 14 | B | ROS cause endothelial dysfunction and disruption in ARDS |
| 15 | B | Leukotrienes use autocrine (self) and paracrine (neighboring cells) signaling |
| 16 | C | Emphysema = protease-antiprotease imbalance; elastase destroys alveolar walls |
| 17 | B | Salty sweat + recurrent infections + malabsorption = Cystic fibrosis; autosomal recessive |
| 18 | C | Leukotriene antagonists (e.g., montelukast) specifically block cysteinyl leukotrienes |
| 19 | B | Smoke inhalation → ARDS → reduced surfactant (DPPC) |
| 20 | C | pH low + pCO₂ very high + HCO₃⁻ slightly elevated = respiratory acidosis with partial renal compensation |
| 21 | B | Panic attack → hyperventilation → respiratory alkalosis; treat with rebreather mask/paper bag |
| 22 | B | Kussmaul breathing = respiratory compensation (hyperventilation) for metabolic acidosis (DKA) |
| 23 | B | Vomiting → loss of HCl → metabolic alkalosis; high pH + high HCO₃⁻ confirm this |
| 24 | B | Altitude hypoxia stimulates peripheral chemoreceptors → hyperventilation → CO₂ blow-off |
| 25 | B | CKD → accumulation of phosphates, sulfates, organic acids = high anion gap metabolic acidosis |
| 26 | B | C4 spinal injury paralyses respiratory muscles → neuromuscular hypoventilation → CO₂ retention |
| 27 | C | DPPC (dipalmitoyl phosphatidylcholine) is the principal lipid in surfactant therapy |
| 28 | C | Tetany and hyperactive reflexes are classic symptoms of metabolic alkalosis |
| 29 | B | Dual mechanism: smoking attracts neutrophils + polymerised abnormal antitrypsin as chemoattractant, with no antiprotease defence |
| 30 | C | Opioid-induced respiratory depression → acute respiratory acidosis; treat with naloxone and restore ventilation |
This is a shared conversation. Sign in to Orris to start your own chat.