Pulmonary

Question 1

Why is lung infarction a rare complication of PE?

Answer 1

Dual circulation from pulmonary and bronchial systems.

Question 2

CF: CFTR is what type of transmembrane protein?

MC mutation?

Answer 2

ATP-gated

Delta F508 - this mutation leads to protein MISFOLDING and failure of glycosylation –> degradation

Question 3

Aspiration: supine

Answer 3

Posterior segments of upper lobes and superior segment of lower lobes

Question 4

Aspiration: upright

Answer 4

Right main bronchus – basilar segments of lower lobes.

Question 5

MOA of pulmonary hypertension

Answer 5

Vasoconstriction due to pulmonary venous congestion

Question 6

Pulmonary vascular bed responds to tissue hypoxia by doing what?

Answer 6

Vasoconstricting
Diverts blood away from underventilated regions to better-ventilated regions. Arterial resistance dec as tissue o2 content inc

Question 7

MC GI disorder in patients with CF?

Answer 7

Pancreatic insufficiency
Viscous secretions in lumens of pancreas –> obstruction, inflam –> fibrosis
Inc risk for def in fat-soluble vit like vit K

Question 8

FEV1/FVC decreased

Answer 8

Obstructive (obstruction reduces FEV1 more than FVC)

Question 9

FEV1/FVC increased

Answer 9

restrictive

May also be normal bc both vol reduced proportionally

Question 10

Decreased TLC/RV is seen in obstructive or restrictive lung disease?

Answer 10

Obstructive (TLC is inc or normal, primarily through expansion of RV)
RV progressively increases

Question 11

Where is airway resistance highest in the respiratory tract?

Answer 11

Medium sized bronchi > trachea > bronchioles >terminal bronchioles

Question 12

What is a normal A-a gradient? Increase occurs in what situations?

Answer 12

10-15mmHg
Normal with alveolar hypoventilation.
Inc: hypoxemia due to shunting (airway obstruction), V/Q mismatch, fibrosis (impaired diffusion)

Question 13

Consider what lung cancer in smokers?

Answer 13

Squamous cell carcinoma. There are SCC pancoast tumors.

Small cell carcinoma also possible.

Question 14

Hereditary pulm arterial HTN is due to an inactivating mutation of BMPR2 - AD, which causes what histologically?

Answer 14

Vascular smooth mm cell proliferation.

Question 15

What is the main lipid component of lung surfactant?

Answer 15

DipalmitoylphosphatidylCHOLINE (DPPC)

Question 16

What type of vessel has the highest resistance in the body and therefore has the highest drop in pressure across the vessel?

Answer 16

Arterioles

Contribute the largest part of total peripheral resistance (systemic vascular resistance)

Question 17

Perfusion-limited equilibration of O2

Answer 17

Normal individual at rest, PE

Question 18

Diffusion-limited equilibration of O2

Answer 18

emphysema, pulm fibrosis, exercise.

Question 19

What are normal tracheal pO2, alveolar pO2, and alveolar pCO2?

Answer 19

Tracheal pO2 - 150
alveolar pO2 - 104
alveolar pCO2 - 40

Question 20

Failure of alveolar gas to reach normal equilibrium point. Presents with approx equal composition of tracheal air and alveolar air.

Answer 20

Perfusion defect: poor alveolar perfusion

e.g. PE

Question 21

Rheumatoid arthritis can cause what pulmonary problem?

Answer 21

Interstitial lung disease (pulm fibrosis)

Question 22

How does ankylosing spondylitis cause hypoventilation?

Answer 22

Thoracic spine and costovertebral and costosternal junctions are involved, limiting chest wall expansion.

Question 23

PE occurs in what vessel?

Answer 23

Pulmonary ARTERY

Question 24

Asbestos exposure inc risk of what malignancies? How can you differentiate them grossly?

Answer 24

Bronchogenic adenocarcomina - peripheral lesions of the lung
Mesothelioma - pleural thickenings
Note: Using immunohistochemistry, CALRETININ can be demonstrated in both benign mesothelium and in malignant mesothelioma
Assoc with ferruginous bodies/fusiform rods
asbestos effects lower lungs. For a particle to affect the lower lungs it has to be <2.5 mew/micro meters.

Question 25

Of the following, which is LAST to disappear as the epithelium changes along the respiratory tube? Goblet cells, cilia, mucous glands, serous glands, cartilage

Answer 25

Cilia Bronchi - have pseudostrat columnar ciliated epithelium + goblet cell, submucosal mucoserous glands and cartilage Bronchioles, terminal broncholes, and resp bronchioles (simple cuboidal) lack goblet cells, glands and cartilage Alveolar macrophages are responsible for helping to clear the lower lobes (alveolar sacs)

Question 26

Impaired CFTR affects Cl, Na and H20 how in the respiratory and intestinal epithelia? Sweat ducts?

Answer 26

Resp/intestine: - Reduced - Cl secretion - Increased - Na and h20 absorption - Causes dehydrated mucus and more neg nasal transepithelial potential difference Sweat: - cant reabsorb Cl and Na --> high Na and Cl in sweat - hyponatremia from excess salt wasting (salt supplements recommended)

Question 27

Differentiate primary ciliary dyskinesia vs CF

Answer 27

Primary ciliary dyskinesia - dynein arm (9+2) defect --> impaired mucociliary clearance, situs inversus, immotile sperm, normal growth, low nasal NO levels. Bronchiectasis CF - mutation in CFTR gene --> chronic sinopulm infx, panc insuff, absent vas def, failure to thrive

Question 28

Where is PVR lowest during spirometry?

Answer 28

At the FRC. | Increased AND decreased lung volumes inc PVR.

Question 29

V/Q scan for PE shows what

Answer 29

PERFUSION defect without ventilation defect | embolus prevents adequate blood perfusion to the affect areas of the lung

Question 30

In DKA, if a patient presents with blood pH 7.27, what does this indicate?

Answer 30

Respiratory failure Normally in DKA, metabolic acidosis is compensated for by resp ALKALOSIS (Kussmaul respirations). If DKA becomes severe enough, resp fatigue, dec mental status, and hypoventilation can cause superimposed respiratory ACIDOSIS

Question 31

Elastases found in alveolar fluid are derived from what?

Answer 31

Infiltrating neutrophils and alveolar macrophages

Question 32

What cell type makes up over 95% of the surface area of the alveoli?

Answer 32

Type I pneumocytes (Squamous cells)

Question 33

What cell type secretes the major components of pulmonary surfactant (phospholipids and dipalmitoyl phosphatidylcholine)? Help with regeneration of alveolar lining

Answer 33

Type II pneumocytes - cuboidal-shaped with electron dense lamellar bodies. (lamellar bodies of type II pneumocytes store and release pulm surfactant)

Question 34

Proteinases of the lung? | Antiproteinases of the lung?

Answer 34

Proteinases: elastase, cathepsin G, MMP Anti-proteinases: a1-antitrypsin, a2-macroglobulin, TIMPS Note: neutrophil elastase is inhibited by a1-antitrypsin macrophage elastase is inhibited by TIMPs (tissue inhibitors of metalloproteinases)

Question 35

Sputum showing eosinophils and Charcot-Leyden crystals is what condition? Immunological mechanism?

Answer 35

Extrinsic allergic asthma | Involves bronchial wall infiltration by eosinophils in response to IL-5 release by allergen-activated TH2 cells

Question 36

What cell contributes to the development of emphysema?

Answer 36

Neutrophils and macrophages - release proteases that degrade the ECM and generate oxygen free radicals that impair protease inhibitors (eg a1-antitrypsin)

Question 37

How can silicosis lead to increase suspectibility to mycobacteria infection?

Answer 37

SIlicosis impairs the macrophage effector arm of cell-mediated immunity Macrophage phagolysosomes may be disrupted by internalized silica particles

Question 38

Superior vena cava syndrome can be caused by what? Sx?

Answer 38

``` Mediastinal mass (eg intrathoracic spread of bronchogenic carcinoma) Impaired venous return to upper body --> dyspnea, facial swelling, and dilated collateral veins in upper trunk ```

Question 39

What is a major RF for ARDS? What happens to lung compliance, work of breathing, V/Q, and PCWP?

Answer 39

pancreatitis Lung compliance - dec work of breathing - inc V/Q - mismatch PCWP - normal (noncardiogenic pulm edema. Elevated PCWP is a sign of cardiogenic pulm edema like w/decomp LV failure) Histo - activated neutrophils in alveolar tissue --> alveoli lined with hyaline membranes

Question 40

Differentiate fat embolism sx from PE

Answer 40

Fat embolism - resp distress, NEURO sx (alt mentation, seizures), PETECHIAL RASH PE - resp distress, tachypnea, tachy, cough, pleuritic chest pain, V/Q mismatch

Question 41

Law of Laplace

Answer 41

Distending pressure (P) = 2T/r T = surface tension r = radius Eg smaller spheres collapse before large ones Surfactant counteracts alveolar collapse by dec surface tension as alveolar radius dec

Question 42

What ratio indicates adequate surfactant production in a neonate?

Answer 42

L/S >=2 L = Lecithin (phosphatidylcholine) S = Sphingomyelin (constant in 3rd tri)

Question 43

Obesity can cause restrictive PFTs. MC indicator of obesity-related disease?

Answer 43

reduction in expiratory reserve volume and functional residual capacity

Question 44

Primary mediators of disease in COPD?

Answer 44

Neutrophils, macrophages, and CD8 T lymphocytes. Secrete enzymes and proteases. Note: inflam cells show impaired ability to phag bacteria also

Question 45

What is the intrapleural pressure in the lung at FRC (ie resting state)

Answer 45

-5 cm H20 Note: chest wall has expanding force on lung --> neg pressure Lungs, due to elasticity have positive transmural pressure, tendency to collapse

Question 46

High altitude does what to pH, pCO2 and pO2?

Answer 46

Resp alkalosis (hyperventilation d/t hypoxia) - compensated by renal excretion of bicarb in 24-48h pH inc pCO2 dec pO2 dec

Question 47

In what situations is Diffusing capacity for carbon monoxide (DLCO) high or low?

Answer 47

High - asthma (inc pulm capillary blood vol) Low - emphysema (destruction of alveoli and adjoining capillary beds) Note: DLCO helps distinguish bw intrinsic vs extrinsic (eg obesity) restrictive lung diseases. Intrinsic has reduced DLCO, extrinsic has normal DLCO.

Question 48

Unilateral pulmonary opacification and deviation of the mediastinum toward the opacified lung is characteristic of what?

Answer 48

Obstruction in a mainstem bronchus. (eg central lung tumors in chronic smokers) Prevents ventilation of an entire lung --> obstructive atelectasis or complete lung collapse

Question 49

Erythema nodosum, arthralgias, hilar lymphadenopathy, and elevated serum ACE levels are common findings in what? Liver histo?

Answer 49

Sarcoidosis | Histo - scattered noncaseating granulomas

Question 50

Pneumoconiosis: eggshell calcification on rim of hilar nodes, birefringent particles surround fibrous tissue on histology

Answer 50

Silicosis Most prominent in apical regions Silica may disrupt phagolysosomes and impair macrophages --> inc risk for Tb

Question 51

Pneumoconiosis: histo of nodal and perilymphatic lung tissue shows accumulations of macrophages filled with what?

Answer 51

Coal | Coal worker's pneumoconiosis

Question 52

Pneumoconiosis: noncaseating epithelioid granulomas without obvious particles on histo

Answer 52

Berylliosis

Question 53

Pneumoconiosis: pleural plaques, assoc with mesothelioma

Answer 53

Asbestosis

Question 54

How can excessively high O2 concentrations in patients with COPD precipitate confusion and depressed consciousness?

Answer 54

inc O2 --> inc CO2 retention (o2-induced hypercapnia) --> confusion and depressed consciousness. Partly d/t reversal of hypoxic pulm vasoconstriction which inc physiologic dead space as the poorly ventilated alveoli are perfused .

Question 55

How can you differentiate diffuse alveolar damage from bronchiolitis obliterans organizing pneumonia?

Answer 55

Diffuse alveolar damage (DAD)---> Increase alveolar capillary permeability---> protein rich leakage into alveoli---->formation of alveolar hyaline membranes. Bronchiolitis obliterans is an inflammatory obstruction of the lung's tiniest airways, called bronchioles. The bronchioles become damaged and inflamed by chemical particles or respiratory infections, particularly after organ transplants, leading to extensive scarring that blocks the airways.

Question 56

Pulm circulation has what characteristic compared to bronchial circulation

Answer 56

Bronchial Arteries branch from the aorta to supply the bronchi and pulmonary connective tissue w/ nourishing, they receive 0.2-1.9% of C.O Meanwhile, Pulmonary circulation receives the rest of the cardiac output.

Question 57

Shunt vs dead space? Which is a PE?

Answer 57

SHUNT= airway obstruction (V/Q=0) DEAD SPACE= blood flow obstruction (V/Q=infinity) PE is an example of dead space

Question 58

Smoking does what to the following: - Mucus production/secretion - Cilia activity - Alveolar macrophage function

Answer 58

- Mucus production/secretion: inc - Cilia activity: dec - Alveolar macrophage function: dec

Question 59

In neonatal resp distress syndrome, what structure is altered in the type II pneumocytes, resulting in less surfactant?

Answer 59

lamellar bodies, keratinosomes or Odland bodies are secretory organelles found in type II pneumocytes and keratinocytes.

Question 60

A healthy patient inhales to total lung capacity and then exhales forcefully. The rate of expiratory airflow is highest at TLC and dec linearly as exhalation continues. Why?

Answer 60

Airway compression - limits flow. Normal: after a small amount of gas has been exhaled, the flow is limited by airway compression and determined by the elastic recoil of the lung and resistance upstream of that point. Restrictive: the maximum flow rate is reduced, as is the total volume expired. The flow is abnormally high in the latter part of expiration because of increased recoil. Obstructive: the flow rate is very low in relation to lung volume, and a scooped out appearance is often seen following the point of maximal flow.

Question 61

What happens to DLCO after ARDS (form of non-cardiogenic pulm edema) resolves

Answer 61

Dec DLCO - pulmonary edema increases the thickness of the alveolo-capillary space, increasing the distance the oxygen must diffuse to reach blood. This impairs gas exchange leading to hypoxia, increases the work of breathing, eventually induces FIBROSIS OF THE AIRSPACE. The hallmark of ARDS is diffuse injury to cells which form the alveolar barrier, surfactant dysfunction, activation of the innate immune response, and abnormal coagulation.[1] In effect, ARDS results in impaired gas exchange within the lungs at the level of the microscopic alveoli.

Question 62

Middle-aged woman with progressive shortness of breath?

Answer 62

Think of idiopathic pulmonary fibrosis, a restrictive lung disease.