NBME CBSE Actual Test Questions and
Answers 2026/2027 | Comprehensive Basic
Science Examination Actual Test Bank with
Verified Correct Answers | USMLE Step 1
Preparation | Latest Version
Hyper Ca causes - ANSWERS-stones, thrones, groans, psych overtones
1-a-hydroxylase in macrophages - ANSWERS-PTH independent conversion
of
Calcifediol to *calcitriol* (bioactive Vit D)
Vit D --> Hyper Ca
Idiopathic pulmonary fibrosis - ANSWERS-*Honeycomb* pattern
loss of Type 1 pneumocytes
*hyperplasia Type II* pneumocytes
Goodpasture - ANSWERS-HS II
Auto-Ab against BM destroys lung alveoli (*restrictive*) and renal glomeruli
Obstructive Lung Disease - ANSWERS-DECREASED FEV1, Decreased FVC
increased RV, FRC, TLC
**different shape
,COPD - ANSWERS-PMN, mo, CD8
*V/Q mismatch:* O2 induced hypercapnia;
physio dead space
Myeloperoxidase causes - ANSWERS-Green sputum/pus
Type II pneumocytes - ANSWERS-surfactant (*lecithin*)
Proliferate after injury
Type I progenitors
*Neonatal Respiratory Distress Syndrome*
Polio live v killed vaccine - ANSWERS-Killed = Salk = IgG
Live = Sabin = IgG + IgA
- can be shed in feces
Neonatal Respiratory Distress:
Etiology + Tx - ANSWERS-Maternal DM (*high insulin*)
or C-section (*low cortisol*)
TX: *dexamethasone* before birth
Lung maturity determined with - ANSWERS-Amniocentesis of Phospholipids
(*type II pneumocytes)
L >> S
Type I pneumocytes - ANSWERS-Squamous gas diffusion
,Elastase in lungs - ANSWERS-macrophage: *lysosomes*
PMN: *azuronphilic granules*
Elastin stretches and recoils due to - ANSWERS-Lysine interchain crosslinks
air pressure and
intrapleural pressure at FRC - ANSWERS-Air pressure = 0
Intrapleural pressure = -5
Pulm Vasc Resistance is lowest during - ANSWERS-Exhale of Tidal Volume
Lung Compliance is decreased by - ANSWERS-LHF, pulmonary edema,
pulmonary fibrosis
Lung Compliance is increased by - ANSWERS-emphysema, age
Obesity affects ERV and FRC - ANSWERS-DECREASE
ERV & FRC
Blood flow/min (pulmonary v systemic) - ANSWERS-pulmonary = systemic
Anatomic pulmonary shunting - ANSWERS-Bronchial circulation causes
*decreased PO2 in LA/LV*
than in pulmonary capillaries
More ventilation is at the - ANSWERS-BASE
, O2-Hgb dissociation LEFT shift - ANSWERS-basic, cold, low 2,3 BPG
low pO2 (compensatory erythrocytosis)
O2-Hgb dissociation RIGHT shift - ANSWERS-low pH, high 2,3BPG, high T
HOT, ACIDIC
CO2 transport to lungs - ANSWERS-*carbonic anhydrase*
Cl shift
*Haldane*: CO2 released to lung
(*Bohr*: O2 release to tissue)
CO poisoning causes - ANSWERS-carboxyhemoglobin
no affect on PaO2
Cyanide poisoning causes - ANSWERS-lactic acidosis
How to treat cyanide poisoning - ANSWERS-*Amyl nitrite* -->
Methemoglobin
THEN *Thiosulfate* (hydroxycobalamin)
Normal A-a gradient - ANSWERS-5-15
Hypoventilation: Heroin OD or high altitude
Increased A-a gradient - ANSWERS-*Diffusion impairment* (fibrosis)
*R-L shunt* (aspiration, ARDS)
Answers 2026/2027 | Comprehensive Basic
Science Examination Actual Test Bank with
Verified Correct Answers | USMLE Step 1
Preparation | Latest Version
Hyper Ca causes - ANSWERS-stones, thrones, groans, psych overtones
1-a-hydroxylase in macrophages - ANSWERS-PTH independent conversion
of
Calcifediol to *calcitriol* (bioactive Vit D)
Vit D --> Hyper Ca
Idiopathic pulmonary fibrosis - ANSWERS-*Honeycomb* pattern
loss of Type 1 pneumocytes
*hyperplasia Type II* pneumocytes
Goodpasture - ANSWERS-HS II
Auto-Ab against BM destroys lung alveoli (*restrictive*) and renal glomeruli
Obstructive Lung Disease - ANSWERS-DECREASED FEV1, Decreased FVC
increased RV, FRC, TLC
**different shape
,COPD - ANSWERS-PMN, mo, CD8
*V/Q mismatch:* O2 induced hypercapnia;
physio dead space
Myeloperoxidase causes - ANSWERS-Green sputum/pus
Type II pneumocytes - ANSWERS-surfactant (*lecithin*)
Proliferate after injury
Type I progenitors
*Neonatal Respiratory Distress Syndrome*
Polio live v killed vaccine - ANSWERS-Killed = Salk = IgG
Live = Sabin = IgG + IgA
- can be shed in feces
Neonatal Respiratory Distress:
Etiology + Tx - ANSWERS-Maternal DM (*high insulin*)
or C-section (*low cortisol*)
TX: *dexamethasone* before birth
Lung maturity determined with - ANSWERS-Amniocentesis of Phospholipids
(*type II pneumocytes)
L >> S
Type I pneumocytes - ANSWERS-Squamous gas diffusion
,Elastase in lungs - ANSWERS-macrophage: *lysosomes*
PMN: *azuronphilic granules*
Elastin stretches and recoils due to - ANSWERS-Lysine interchain crosslinks
air pressure and
intrapleural pressure at FRC - ANSWERS-Air pressure = 0
Intrapleural pressure = -5
Pulm Vasc Resistance is lowest during - ANSWERS-Exhale of Tidal Volume
Lung Compliance is decreased by - ANSWERS-LHF, pulmonary edema,
pulmonary fibrosis
Lung Compliance is increased by - ANSWERS-emphysema, age
Obesity affects ERV and FRC - ANSWERS-DECREASE
ERV & FRC
Blood flow/min (pulmonary v systemic) - ANSWERS-pulmonary = systemic
Anatomic pulmonary shunting - ANSWERS-Bronchial circulation causes
*decreased PO2 in LA/LV*
than in pulmonary capillaries
More ventilation is at the - ANSWERS-BASE
, O2-Hgb dissociation LEFT shift - ANSWERS-basic, cold, low 2,3 BPG
low pO2 (compensatory erythrocytosis)
O2-Hgb dissociation RIGHT shift - ANSWERS-low pH, high 2,3BPG, high T
HOT, ACIDIC
CO2 transport to lungs - ANSWERS-*carbonic anhydrase*
Cl shift
*Haldane*: CO2 released to lung
(*Bohr*: O2 release to tissue)
CO poisoning causes - ANSWERS-carboxyhemoglobin
no affect on PaO2
Cyanide poisoning causes - ANSWERS-lactic acidosis
How to treat cyanide poisoning - ANSWERS-*Amyl nitrite* -->
Methemoglobin
THEN *Thiosulfate* (hydroxycobalamin)
Normal A-a gradient - ANSWERS-5-15
Hypoventilation: Heroin OD or high altitude
Increased A-a gradient - ANSWERS-*Diffusion impairment* (fibrosis)
*R-L shunt* (aspiration, ARDS)
