NBME CBSE Practice Exam 2026 | Questions &
Explanations PDF
Type II pneumocytes - correct Answerssurfactant (*lecithin*)
Proliferate after injury
Type I progenitors
*Neonatal Respiratory Distress Syndrome*
Polio live v killed vaccine - correct AnswersKilled = Salk = IgG
Live = Sabin = IgG + IgA
- can be shed in feces
Neonatal Respiratory Distress:
Etiology + Tx - correct AnswersMaternal DM (*high insulin*)
or C-section (*low cortisol*)
TX: *dexamethasone* before birth
Lung maturity determined with - correct AnswersAmniocentesis of Phospholipids (*type
II pneumocytes)
L >> S
Type I pneumocytes - correct AnswersSquamous gas diffusion
Elastase in lungs - correct Answersmacrophage: *lysosomes*
PMN: *azuronphilic granules*
Elastin stretches and recoils due to - correct AnswersLysine interchain crosslinks
air pressure and
intrapleural pressure at FRC - correct AnswersAir pressure = 0
Intrapleural pressure = -5
Pulm Vasc Resistance is lowest during - correct AnswersExhale of Tidal Volume
Lung Compliance is decreased by - correct AnswersLHF, pulmonary edema,
pulmonary fibrosis
Lung Compliance is increased by - correct Answersemphysema, age
Obesity affects ERV and FRC - correct AnswersDECREASE
ERV & FRC
,Blood flow/min (pulmonary v systemic) - correct Answerspulmonary = systemic
Anatomic pulmonary shunting - correct AnswersBronchial circulation causes
*decreased PO2 in LA/LV*
than in pulmonary capillaries
More ventilation is at the - correct AnswersBASE
O2-Hgb dissociation LEFT shift - correct Answersbasic, cold, low 2,3 BPG
low pO2 (compensatory erythrocytosis)
O2-Hgb dissociation RIGHT shift - correct Answerslow pH, high 2,3BPG, high T
HOT, ACIDIC
CO2 transport to lungs - correct Answers*carbonic anhydrase*
Cl shift
*Haldane*: CO2 released to lung
(*Bohr*: O2 release to tissue)
CO poisoning causes - correct Answerscarboxyhemoglobin
no affect on PaO2
Cyanide poisoning causes - correct Answerslactic acidosis
How to treat cyanide poisoning - correct Answers*Amyl nitrite* --> Methemoglobin
THEN *Thiosulfate* (hydroxycobalamin)
Normal A-a gradient - correct Answers5-15
Hypoventilation: Heroin OD or high altitude
Increased A-a gradient - correct Answers*Diffusion impairment* (fibrosis)
*R-L shunt* (aspiration, ARDS)
*V/Q mismatch* (pulmonary edema
AT --> AT II
where and how - correct AnswersACE
(- high in sarcoidosis)
In small pulmonary bV
C5a induces what - correct AnswersPMN influx (ie: in lungs)
Korotkoff sound - correct AnswersBP cuff - appear and disappear
in inflation/deflation
Pulsus Paradoxus - correct Answers10mmHg difference in
,Korotkoff sound
Pulsus Paradoxus occurs in - correct AnswersCardiac Tamponade
Kussmaul sign - correct AnswersJVP rises *during inspiration*
Constrictive Pericardiditis
Restrictive/Interstitial Lung Disease:
A-a, FVC, FEV1, EFR - correct AnswersAirway widening due to *radial traction* from
fibrosis
*increase Aa*
decreased FVC & FEV1
*Increased EFR*
Sarcoidosis - correct Answers*Th1 *noncaseating granulmona
bilateral hilar adenopathy
increased *ACE*
increased IL2, IFNg
1-a-hydroxylase in macrophages: vit D --> *HyperCa*
Hyper Ca causes - correct Answersstones, thrones, groans, psych overtones
1-a-hydroxylase in macrophages - correct AnswersPTH independent conversion of
Calcifediol to *calcitriol* (bioactive Vit D)
Vit D --> Hyper Ca
Idiopathic pulmonary fibrosis - correct Answers*Honeycomb* pattern
loss of Type 1 pneumocytes
*hyperplasia Type II* pneumocytes
Goodpasture - correct AnswersHS II
Auto-Ab against BM destroys lung alveoli (*restrictive*) and renal glomeruli
Obstructive Lung Disease - correct AnswersDECREASED FEV1, Decreased FVC
increased RV, FRC, TLC
**different shape
COPD - correct AnswersPMN, mo, CD8
*V/Q mismatch:* O2 induced hypercapnia;
physio dead space
Myeloperoxidase causes - correct AnswersGreen sputum/pus
Do not give O2 supplement to - correct AnswersCOPD patient
, Decreased stimulation of
*carotid bodies* = decreased RR
TX COPD with - correct Answers*Fluticasone* (glucocorticoid)
inhibit cellular reaction
a1-antitrypsin deficiency - correct AnswersSerine protease inhibitor
*LIVER*
*LUNG*: inc PMN elastase --> emphysema
Asthma dx - correct Answers*Methacholine* (maCh) challenge
= induce bronchoconstriction
to reduce FEV1
+ test = Airways ARE reactive
B2 agonist MOA - correct AnswersB2 (Gs) --> AC --> increase *cAMP*
Corticosteroid MOA - correct Answersinhibit cytokine synthesis
suppress T lymphocyte
mACh Antagonist ("tropium") MOA - correct Answers*inhibit Vagal* via ACh
--> decreased Ca
OSA causes - correct Answerspulmonary HTN and RHF
increases EPO which worsens HTN
EPO can do what
on Cardiovascular - correct Answersworsen HTN
Pulmonary Arterial HTN - correct Answers*BMPR2*
High *endothelin*, Low NO
SMC hypertophy, fibrosis, narrow lumen
*P2 louder* than A2
When is P2 louder than A2 - correct AnswersPulmonary Artherial Hypertension
TX pulmonary arterial hypertension - correct AnswersEndothelin-R antagonist:
- Bo*sentan*, Ambi*sentan*
PGEi (inc cGMP):
- Silden*afil*
Pulmonary Embolism - correct Answers*perfusion defect* (V/Q mismatch)
sudden SOB + calf swelling
Hypoxemia --> *Hyperventilate *
--> *Respiratory Alkalosis *
Explanations PDF
Type II pneumocytes - correct Answerssurfactant (*lecithin*)
Proliferate after injury
Type I progenitors
*Neonatal Respiratory Distress Syndrome*
Polio live v killed vaccine - correct AnswersKilled = Salk = IgG
Live = Sabin = IgG + IgA
- can be shed in feces
Neonatal Respiratory Distress:
Etiology + Tx - correct AnswersMaternal DM (*high insulin*)
or C-section (*low cortisol*)
TX: *dexamethasone* before birth
Lung maturity determined with - correct AnswersAmniocentesis of Phospholipids (*type
II pneumocytes)
L >> S
Type I pneumocytes - correct AnswersSquamous gas diffusion
Elastase in lungs - correct Answersmacrophage: *lysosomes*
PMN: *azuronphilic granules*
Elastin stretches and recoils due to - correct AnswersLysine interchain crosslinks
air pressure and
intrapleural pressure at FRC - correct AnswersAir pressure = 0
Intrapleural pressure = -5
Pulm Vasc Resistance is lowest during - correct AnswersExhale of Tidal Volume
Lung Compliance is decreased by - correct AnswersLHF, pulmonary edema,
pulmonary fibrosis
Lung Compliance is increased by - correct Answersemphysema, age
Obesity affects ERV and FRC - correct AnswersDECREASE
ERV & FRC
,Blood flow/min (pulmonary v systemic) - correct Answerspulmonary = systemic
Anatomic pulmonary shunting - correct AnswersBronchial circulation causes
*decreased PO2 in LA/LV*
than in pulmonary capillaries
More ventilation is at the - correct AnswersBASE
O2-Hgb dissociation LEFT shift - correct Answersbasic, cold, low 2,3 BPG
low pO2 (compensatory erythrocytosis)
O2-Hgb dissociation RIGHT shift - correct Answerslow pH, high 2,3BPG, high T
HOT, ACIDIC
CO2 transport to lungs - correct Answers*carbonic anhydrase*
Cl shift
*Haldane*: CO2 released to lung
(*Bohr*: O2 release to tissue)
CO poisoning causes - correct Answerscarboxyhemoglobin
no affect on PaO2
Cyanide poisoning causes - correct Answerslactic acidosis
How to treat cyanide poisoning - correct Answers*Amyl nitrite* --> Methemoglobin
THEN *Thiosulfate* (hydroxycobalamin)
Normal A-a gradient - correct Answers5-15
Hypoventilation: Heroin OD or high altitude
Increased A-a gradient - correct Answers*Diffusion impairment* (fibrosis)
*R-L shunt* (aspiration, ARDS)
*V/Q mismatch* (pulmonary edema
AT --> AT II
where and how - correct AnswersACE
(- high in sarcoidosis)
In small pulmonary bV
C5a induces what - correct AnswersPMN influx (ie: in lungs)
Korotkoff sound - correct AnswersBP cuff - appear and disappear
in inflation/deflation
Pulsus Paradoxus - correct Answers10mmHg difference in
,Korotkoff sound
Pulsus Paradoxus occurs in - correct AnswersCardiac Tamponade
Kussmaul sign - correct AnswersJVP rises *during inspiration*
Constrictive Pericardiditis
Restrictive/Interstitial Lung Disease:
A-a, FVC, FEV1, EFR - correct AnswersAirway widening due to *radial traction* from
fibrosis
*increase Aa*
decreased FVC & FEV1
*Increased EFR*
Sarcoidosis - correct Answers*Th1 *noncaseating granulmona
bilateral hilar adenopathy
increased *ACE*
increased IL2, IFNg
1-a-hydroxylase in macrophages: vit D --> *HyperCa*
Hyper Ca causes - correct Answersstones, thrones, groans, psych overtones
1-a-hydroxylase in macrophages - correct AnswersPTH independent conversion of
Calcifediol to *calcitriol* (bioactive Vit D)
Vit D --> Hyper Ca
Idiopathic pulmonary fibrosis - correct Answers*Honeycomb* pattern
loss of Type 1 pneumocytes
*hyperplasia Type II* pneumocytes
Goodpasture - correct AnswersHS II
Auto-Ab against BM destroys lung alveoli (*restrictive*) and renal glomeruli
Obstructive Lung Disease - correct AnswersDECREASED FEV1, Decreased FVC
increased RV, FRC, TLC
**different shape
COPD - correct AnswersPMN, mo, CD8
*V/Q mismatch:* O2 induced hypercapnia;
physio dead space
Myeloperoxidase causes - correct AnswersGreen sputum/pus
Do not give O2 supplement to - correct AnswersCOPD patient
, Decreased stimulation of
*carotid bodies* = decreased RR
TX COPD with - correct Answers*Fluticasone* (glucocorticoid)
inhibit cellular reaction
a1-antitrypsin deficiency - correct AnswersSerine protease inhibitor
*LIVER*
*LUNG*: inc PMN elastase --> emphysema
Asthma dx - correct Answers*Methacholine* (maCh) challenge
= induce bronchoconstriction
to reduce FEV1
+ test = Airways ARE reactive
B2 agonist MOA - correct AnswersB2 (Gs) --> AC --> increase *cAMP*
Corticosteroid MOA - correct Answersinhibit cytokine synthesis
suppress T lymphocyte
mACh Antagonist ("tropium") MOA - correct Answers*inhibit Vagal* via ACh
--> decreased Ca
OSA causes - correct Answerspulmonary HTN and RHF
increases EPO which worsens HTN
EPO can do what
on Cardiovascular - correct Answersworsen HTN
Pulmonary Arterial HTN - correct Answers*BMPR2*
High *endothelin*, Low NO
SMC hypertophy, fibrosis, narrow lumen
*P2 louder* than A2
When is P2 louder than A2 - correct AnswersPulmonary Artherial Hypertension
TX pulmonary arterial hypertension - correct AnswersEndothelin-R antagonist:
- Bo*sentan*, Ambi*sentan*
PGEi (inc cGMP):
- Silden*afil*
Pulmonary Embolism - correct Answers*perfusion defect* (V/Q mismatch)
sudden SOB + calf swelling
Hypoxemia --> *Hyperventilate *
--> *Respiratory Alkalosis *
