Usmle Step 1 Flashcards - Respiratory

Front 1

Where is cartilage present in the respiratory system?

Back 1

Only trachea and bronchi

Front 2

Where do the pseudostratified ciliated columnar cells extend to?

Back 2

Respiratory bronchioles (first part of respiratory zone)

Front 3

Where do the goblet cells extend to?

Back 3

Only to the bronchi

Front 4

Appearance of type II pneumocytes on histology?

Back 4

Cuboidal and clustered

Front 5

Cell type that proliferates during lung damage?

Back 5

Type II pneumocytes
- serve as precursors for type I and other type II cells

Front 6

Functions and appearance of Clara cells?

Back 6

Secrete component of surfactant, degrade toxins, act as reserve cells.

Nonciliated, columnar with secretory granules.

Front 7

Ratio that indicates fetal lung maturity?

Back 7

Lecithin-to-sphingomyelin ratio > 2 in amniotic fluid

Front 8

What travels with the esophagus through the diaphragm at T10?

Back 8

Vagus (2 trunks)

Front 9

What travels with the aorta through the diaphragm at T12?

Back 9

Thoracic duct and azygous vein
- Red, white, & blue: aorta, thoracic duct, and azygous vein

Front 10

Pain from the phrenic nerve (diaphragm) is referred to where?

Back 10

Shoulder

Front 11

Components of a bronchopulmonary segment?

Back 11

Tertiary (segmental) bronchus/bronchiole
2 arteries (bronchial and pulmonary)
Veins and lymphatics (at the border)

Front 12

What is the function of the elastic walls of the pulmonary arterial circulation?

Back 12

Maintain pulmonary arterial pressure at relatively constant levels throughout the cardiac cycle

Front 13

Reason for inhaled foreign body on right side?

Back 13

Right main stem bronchus is wider and more vertical than the left

Front 14

Relationship of pulmonary artery to bronchus at each lung hilus?

Back 14

Right: Pulmonary artery ANTERIOR to bronchus
Left: pulmonary artery SUPERIOR to bronchus
(R-A-L-S)

Front 15

Fissure that separates right superior and middle lobes?

Back 15

Horizontal fissure

Front 16

What does the oblique fissure separate?

Back 16

Inferior and superior lobes of each lung
R front: inferior and middle lobe

Front 17

Muscles that help with inspiration?

Back 17

External intercostals, scalene muscles, SCM

Front 18

Muscles that help with expiration?

Back 18

Rectus abdominis, internal and external obliques, transversus abdominis, internal intercostals

Front 19

Alveolar collapsing pressure equation?

Back 19

P = 2 (surface tension) / radius

- tendency to collapse on expiration as radius decreases

Front 20

Factors that favor T over R form of hemoglobin?

Back 20

Increased Cl, H+, CO2, 2,3-BPG

(negative allostery)

Front 21

T vs R form of O2?

Back 21

T (taut): low affinity for O2
R (relaxed): high affinity (300x) for O2

Front 22

What accounts for the sigmoid shaped O2 dissociation curve for Hgb?

Back 22

Positive cooperativity and negative allostery

Front 23

Pressures at FRC?

Back 23

Airway/alveolar pressure is 0 (atmospheric)

Intrapleural pressure is negative (~ -5)

Front 24

Forces from chest wall and lungs at FRC?

Back 24

Chest wall is pulling outward (exerting negative airway pressure)

Lungs are pulling inward (exerting positive airway pressure)

Front 25

Largest contributor of dead space in healthy lung?

Back 25

Apex of healthy lung (functional dead space)

Front 26

Dead space equation?

Back 26

VD = VT x (PaCO2 - PeCO2)/PaCO2

Front 27

Factors that shift O2-Hb dissociation curve to left?

Back 27

Decreased PCO2, temperature, H+, 2,3-DPG
Fetal Hgb
Decreased metabolic needs

Front 28

Factors that shift O2-Hb dissociation curve to right?

Back 28

Increased PCO2, temperature, H+, 2,3-DPG
High altitude
Increased metabolic needs

Front 29

What does pulmonary HTN result in?

Back 29

Atherosclerosis, medial hypertrophy, and intimal fibrosis of pulmonary artery

Front 30

Cause of primary pulmonary HTN?

Back 30

Inactivating BMPR2 mutation (normally inhibits vascular smooth muscle proliferation)

Front 31

Secondary causes of pulmonary HTN?

Back 31

COPD
Mitral stenosis
Recurrent thromboemboli
Autoimmune disease
L to R shunt
Sleep apnea or high altitude

Front 32

Diffusion equation?

Back 32

Vgas = A/T x Dk(P1-P2)

Front 33

Perfusion limited gases?

Back 33

O2 (normal lung), CO2, N2O

Gas equilibrates early along the length of the capillary. Diffusion only increases if blood flow increases.

Front 34

Diffusion limited gases?

Back 34

O2 (emphysema, fibrosis), CO

Gas does NOT equilibrate by the time blood reaches the end of the capillary.

Front 35

Cardiac finding in people living in high altitude?

Back 35

RV hypertrophy (due to chronic hypoxic pulmonary vasoconstriction)

Front 36

General resistance equation?

Back 36

R = (8nl) / (pi) (r^4)

Front 37

Pulmonary vascular resistance equation?

Back 37

PVR = (P pulm artery - P L atrium) / cardiac output

Front 38

Deoxygenated Hb level for cyanosis to appear?

Back 38

Deoxygenated Hb > 5 g/dL

Front 39

Alveolar gas equation?

Back 39

PAO2 = PIO2 - PACO2/R

... = 150 - PACO2/0.8

Front 40

Where in the lung is V/Q ratio the highest?

Back 40

Highest in the apex (V/Q ~ 3)
(wasted ventilation)

Base of the lung: V/Q ~ 0.6
(wasted perfusion)

Front 41

What happens to the V/Q ratio with exercise?

Back 41

V/Q approaches 1
- vasodilation of the apical capillaries

Front 42

What is the Haldane effect?

Back 42

Lungs: Oxygenation of Hb promotes dissociation of H+ from Hb --> shifts equilibrium toward CO2 formation --> CO2 released from RBCs and into alveoli

Front 43

What is the Bohr effect?

Back 43

Peripheral tissue: H+ from tissue metabolism shifts the curve to the right --> helps O2 unload

Front 44

3 forms of transport of CO2?

Back 44

1. HCO3 (90%)
2. Carbaminohemoglobin (bound to N terminal of globin) (5%)
3. Dissolved CO2 (5%)

Front 45

What are the hilar nodes in sarcoid hilar lymphadenopathy referred to as?

Back 45

Potato nodes

Front 46

What can eosinophilic granuloma (histiocytosis X cause) in the lung?

Back 46

Interstitial lung disease - restrictive lung disease

Front 47

Drugs that can cause interstitial lung disease?

Back 47

Bleomycin, Busulfan, Amiodarone, Cyclophosphamide, Methotrexate, Nitrofurantoin, Nitrosourea

Front 48

Most abundant time of surfactant production?

Back 48

After 35th week of gestation

Front 49

Complication of neonatal respiratory distress?

Back 49

Persistent low O2 tension leads to risk of PDA

Front 50

Complication of therapeutic supplemental O2 in neonates?

Back 50

Retinopathy of prematurity and bronchopulmoary dysplasia

Front 51

CXR appearance of neonatal RDS?

Back 51

"Ground-glass" appearance

Front 52

Risk factors for neonatal RDS?

Back 52

- Prematurity
- Maternal diabetes (insulin decreases surfactant production)
- Cesarean delivery (decreased glucocorticoid release)

Front 53

Treatments for neonatal RDS?

Back 53

Maternal steroids before birth
Artificial surfactant for infant
Thyroxine

Front 54

Cause of initial damage in ARDS?

Back 54

Neutrophilic substances that are toxic to alveolar wall, activation of coagulation cascade, and O2-derived free radicals

Front 55

Criteria for ARDS?

Back 55

1. Non-cardiogenic pulmonary edema (wedge < 18)
2. Bilateral infiltrates on CXR
3. PaO2/FiO2 < 200

Front 56

Types of emboli?

Back 56

Fat
Air
Thrombus
Bacteria
Amniotic fluid
Tumor

Front 57

Tests to diagnose PE?

Back 57

Helical CT, CT angio, V/Q scan, D-dimers

Front 58

What is Homans' sign?

Back 58

Resistance/pain/tenderness in calf muscle with dorsiflexion of the foot
- seen with DVT

Front 59

What is the Reid index?

Back 59

Gland depth divided by total thickness of bronchial wall
> 50% in COPD (hypertrophy of mucus-secreting glands in bronchioles)

Front 60

Clinical findings in COPD?

Back 60

Wheezing, crackles, cyanosis (shunting), late onset dyspnea

Front 61

Findings in paraseptal emphysema?

Back 61

Associated with bullae that can rupture and cause spontaneous pneumothorax
Often occurs in young, healthy males

Front 62

What are Curschmann's spirals?

Back 62

Shed epithelium from mucus plugs
- Seen in asthma

Front 63

Pathology of asthma?

Back 63

Bronchial hyper-responsiveness --> causes reversible bronchoconstriction with smooth muscle hypertrophy

Front 64

Clinical findings in emphysema?

Back 64

Dyspnea, decreased breath sounds, tachycardia, LATE onset hypoxemia (loss of capillary beds and alveolar walls), EARLY onset dyspnea

Front 65

What is bronchiectasis associated with?

Back 65

Bronchial obstruction, CF, poor ciliary motility, Kartagener's
--> can develop aspergillosis

Front 66

Pneumoconiosis that affects lower lobes?

Back 66

Asbestosis

Coal miner's and silicosis both affect UPPER lobes.

Front 67

What do asbestos bodies look like?

Back 67

Golden-brown fusiform rods (dumbbell-like), coated with ferritin, located inside macrophages

Front 68

Disease with "dust cells" and "black lung"? Complications?

Back 68

Coal miner's lung (anthracosis)

Complications: cor pulmonale, Caplan's syndrome

Front 69

What happens to the pleura with asbestosis?

Back 69

Develop "ivory white" calcified pleural plaques

Front 70

Interaction of silica with macrophages?

Back 70

Macrophages respond by releasing fibrogenic factors --> fibrosis
- Silica disrupts phagolysosomes/impairs macs --> susceptible to TB

Front 71

Associations with sleep apnea?

Back 71

Obesity, loud snoring, systemic/pulmonary HTN, arrhythmias, big tonsils, nasal septum deviation, possible sudden death

Front 72

Fremitus is increased in what?

Back 72

Lobar pneumonia

Front 73

Causes of tracheal deviation?

Back 73

Bronchial obstruction (w/ resorption atelectasis): deviates toward side of lesion

Tension pneumothorax or severe pleural effusion (w/ compression atelectasis): deviates away from side of lesion

Front 74

Common metastases TO lung?

Back 74

Breast, colon, prostate, bladder, renal

Front 75

Common sites of metastasis FROM lung?

Back 75

Adrenals, brain, bone, liver

Front 76

"SPHERE" of complications of lung cancer?

Back 76

Superior vena cava syndrome
Pancoast's tumor
Horner's syndrome
Endocrine (paraneoplastic)
Recurrent laryngeal symptoms (hoarseness)
Effusions (pleural/pericardial)

Front 77

Most common cause of superior sulcus tumor?

Back 77

Squamous cell
- also central, linked to smoking

Front 78

Most common lung cancer in non-smokers?

Back 78

Adenocarcinoma

Front 79

Where does adenocarcinoma develop?

Back 79

Peripheral areas
- often in site of prior pulmonary inflammation or injury

Front 80

Highly anaplastic undifferentiated tumor?

Back 80

Large cell carcinoma
- often found peripherally
- pleomorphic giant cells with leukocyte fragments in cytoplasm

Front 81

Neoplasm of neuroendocrine Kulchitsky cells?

Back 81

Small (oat) cell carcinoma
- undifferentiated can be very aggressive

Front 82

Main difference between first and second generation H1 blockers?

Back 82

Second generation: far less sedating (decreased CNS entry)

Front 83

Names of first and second generation H1 blockers?

Back 83

1st gen: Diphenhydramine, dimenhydrinate, chlorpheniramine

2nd gen: Loratadine, fexofenadine, desloratadine, cetirizine

Front 84

Common bugs in lung abscesses?

Back 84

S. aureus or anaerobes
- sometimes Prevotella, Fusobacterium, Klebsiella

Front 85

What is Guaifenesin?

Back 85

An expectorant that removes excess sputum but does not suppress the cough reflex

Front 86

Most common causes of lung abscess?

Back 86

Bronchial obstruction (ie: cancer) or aspiration of oropharyngeal contents (esp alcoholics and epileptics)

Front 87

Common causes of bronchopneumonia?

Back 87

S. aureus, H. flu, Klebsiella, S. pyogenes

Front 88

Most common causes of interstitial (atypical) pneumonia?

Back 88

Viruses (RSV, adenovirus), Mycoplasma, Legionella, Chlamydia

Front 89

Mast cell stabilizer for prophylaxis of asthma attacks but NOT effective during an acute attack?

Back 89

Cromolyn

Front 90

Mechanism of Beclomethasone and Prednisone for asthma?

Back 90

Inhibit cytokine production, inactivate NF-kB (induces TNF-alpha)
- 1st line therapy for chronic asthma

Front 91

Zileuton vs Zafir/Montelukast?

Back 91

Zileuton: inhibits production of leukotrienes

Zafir/montelukase: block leukotriene receptors
- especially good for aspirin induced asthma

Front 92

Theophylline mechanism and AE?

Back 92

Inhibit phosphodiesterase --> increase cAMP --> bronchodilation
- AE: cardio and neurotoxicity

Front 93

AEs of Salmeterol?

Back 93

Tremor and arrhythmia
(long acting beta2 agonist)

Front 94

Muscarinic antagonists and theophylline inhibit the actions of what and what?

Back 94

Muscarinic antagonists: inhibit ACh action

Theophylline: inhibit adenosine action

- ACh and adenosine normally cause bronchoconstriction