Obstructive Lung Disease

Question 1

Where is pseudostratified ciliated columnar epithelium found in the lung?

Answer 1

Airways proximal to RBs lined by pseudostratified ciliated columnar epithelium

Question 2

Where does the normal acinus start?

Answer 2

starts distal to terminal bronchiole

Question 3

What types of cells are in the alveolus?

Answer 3

Type I pneumocytes:
cover 95% of alveolar
surface and are the diffusion surface

Type II pneumocytes: Produce surfactant & Repair of alveolar
epithelium

Question 4

What are pores of Kohn?

Answer 4

alveola septa are not continuous but have the pores of Kohn

Question 5

Define OPD:

Answer 5

Diseases that cause obstruction to airflow out of the lungs

Question 6

What are the types of COPD?

Answer 6

– Emphysema
– Chronic bronchitis
– Asthma
– Bronchiectasis

Question 7

What is FVC?

Answer 7

Forced vital capacity (FVC)– Lungs are forcibly emptied at maximal speed from point of full inspiration

Question 8

What is FEV1?

Answer 8

Forced expiratory volume in 1 second

Question 9

What is the FEV1:FVC ratio used for?

Answer 9

useful for detecting obstruction and differentiating obstructive from restrictive lung disease

Question 10

What happens in obstructive airway disease?

Answer 10

• Airway disorder – trachea to terminal bronchiole
• Increased resistance to air flow and limited expiratory rates on forced expiration
• Reduced FEV1:FVC ratio

Question 11

What happens in restrictive airway disease?

Answer 11

• Parenchymal disorder -respiratory bronchiole, alveoli and alveolar ducts
• Decreased expansion with reduced Total Lung Capacity, O2 diffusing capacity, Lung Volumes and compliance
• Increased FEV1:FVC ratio

Question 12

What is Emphysema?

Answer 12

Permanent enlargement of all or part of the respiratory unit (respiratory bronchioles, alveolar ducts, alveoli) accompanied by wall destruction without obvious fibrosis due to a protease imbalance

Question 13

What are some causes of emphysema?

Answer 13

– Smoking (tobacco, marijuana)
– Air pollution
– α1-antitrypsin deficiency

Question 14

What are the two types of emphysema?

Answer 14

– Centriacinar (centrilobular) – 95% cases

– Panacinar

Question 15

What is the pathogenesis of emphysema?

Answer 15

Increased numbers of macrophages, CD8+ T lymphocytes and neutrophils activated by tissue damage from cigarette smoke

Elastase and free radicals derive from neutrophils and macrophages –> Destruction of elastic tissue –>Increased compliance and decreased elasticity

Question 16

What is a disease of Elastic tissue → keeps airway lumens open by applying traction → elastic destruction causes collapse of airways on expiration → prevents exit of air → trapped air distends part of respiratory unit that has lost the elastic support → dilatation and destruction of alveoli and alveolar ducts (also distal/terminal bronchioles)?

Answer 16

Emphysema

Question 17

What is Centriacinar emphysema?

Answer 17

Smokers’ emphysema in Apical segments of upper lobes

Question 18

How does smoking cause Centriacinar emphysema?

Answer 18

Tobacco smoke contains “free radicals” which deplete these antioxidants and Oxidative injury also inactivates native antiproteases – “functional α1-antitrypsin deficiency”

Question 19

What is Panacinar emphysema?

Answer 19

α1-antitrypsin deficiency: Lower lobes All parts of the respiratory unit are affected by elastic tissue destruction

Question 20

What causes Panacinar emphysema?

Answer 20

genetic or aquired (smoking)

genetic is autosomal dominant with phenotypes associated with severe deficiency of α1-antitrypsin enzyme production in the liver

Question 21

What are the clinical findings with emphysema?

Answer 21

– Severe and early onset of dyspnea
– Pink puffers
– Coexistence with chronic bronchitis (smokers’ emphysema)
– Cor pulmonale – less common than in chronic bronchitis
– Diminished breath sounds due to hyperinflation

Question 22

What can you see on a chest xray of emphysema?

Answer 22

– Increased AP diameter
– Hyperlucent lung fields
– Vertical heart
– Depressed diaphragm

Question 23

What are some other types of emphysema?

Answer 23

• Paraseptal emphysema (Subpleural involvement, Spontaneous pneumothorax, No COPD)
• Irregular emphysema (Localized, scar associated, No COPD)

Question 24

What is chronic bronchitis?

Answer 24

Productive cough for at least 3 months for 2 consecutive years

Question 25

What are some causes of chronic bronchitis?

Answer 25

– Smoking | – Cystic fibrosis

Question 26

What is the pathogenesis of chronic bronchitis?

Answer 26

– Inhaled smoke (irritant) → mucous hypersecretion in bronchi → airflow obstruction in terminal bronchioles (more proximal than in emphysema) → irreversible fibrosis of terminal bronchioles – Infection: Maintenance of disease andAcute exacerbations – Bronchospasm

Question 27

How do airways look in chronic bronchitis?

Answer 27

mucous overproduction, constriction of bronchiole with bronchospasm/smooth muscle hyperplasia, edema, erythema

Question 28

What are the clinical findings with chronic broncnitis?

Answer 28

``` – Productive cough – Cyanosis (due to decreased O2 saturation from hypoxemia) – “Blue bloaters” – Dyspnea – Expiratory wheezing and rhonchi – Cor pulmonale ```

Question 29

What would you see on a chest xray of chronic bronchitis?

Answer 29

– Enlarged heart, horizontally oriented | – Increased bronchial markings

Question 30

What about on histology for chronic bronchitis?

Answer 30

blue inflammatory cells, mucous gland hyperplasia, thickening of walls, narrow lumens

Question 31

How is mucous gland hyperplasia measured?

Answer 31

Reid Index | • Ratio of the thickness of the mucous gland layer to the thickness of the wall between the epithelium and cartilage

Question 32

What is Bronchiectasis?

Answer 32

Permanent destruction and dilatation of bronchi and bronchioles involves cartilage and elastic tissue

Question 33

What are some causes of Bronchiectasis?

Answer 33

– Cystic fibrosis – Infections: TB, Adenovirus, H influenzae, staph aureus – Bronchial obstruction – Primary ciliary dyskinesia – Allergic bronchopulmonary aspergillosis

Question 34

What are the clinical findings of Bronchiectasis?

Answer 34

– Copious sputum – Hemoptysis – Digital clubbing – Cor pulmonale

Question 35

What would you see on a chest xray of Bronchiectasis?

Answer 35

Bronchial markings extending to the periphery of the lungs

Question 36

What are the gross findings of Bronchiectasis?

Answer 36

dilated airways filled with mucous and pus

Question 37

What are the microscopic findings of Bronchiectasis?

Answer 37

– Intense acute and chronic inflammatory exudate in bronchial walls, necrotizing ulceration – Squamous metaplasia of bronchial epithelium – Lung abscesses may be present – Fibrosis of bronchial walls leading to bronchiolitis obliterans – Cultures are usually positive

Question 38

What is cystic fibrosis?

Answer 38

Autosomal recessive Deletion on chromosome 7 causing Defective CF transmembrane conductance regulator (CFTR) for chloride ions

Question 39

What is the pathogenesis of CF?

Answer 39

Increased Na and water reabsorption from luminal secretions and decreased Cl secretions from epithelial cells into lumen so Dehydration of body secretions due lack of NaCl – bronchioles, pancreatic ducts, bile ducts, meconium, seminal fluid

Question 40

What are the clinical findings in CF?

Answer 40

``` – Nasal polyps – Respiratory infections → Respiratory failure – Malabsorption – Type I diabetes mellitus – Infertility in males – Meconium ileus – Secondary biliary cirrhosis ```

Question 41

A pt has recent 20 lb weight loss associated with rapid onset SOB what is the most likely diagnosis?

Answer 41

lung cancer

Question 42

Do swollen feet and significant sputum production occur in asthma?

Answer 42

Nope

Question 43

What if a pt has seasonality to their breathing symptoms?

Answer 43

probably allergies and asthma

Question 44

Asthma is usually _____ airway obstruction while COPD is usually _______

Answer 44

asthma: reversible COPD: not reversible

Question 45

– Usually related to smoking exposure – Obstruction generally not reversible with a beta-agonist – Reduced gas exchange – Emphysema – Chronic bronchitis – Associated diseases: Right heart failure / Congestive heart failure & Lung cancer What's going on here?

Answer 45

COPD

Question 46

– Usually develops early in life: Viral induction and exacerbation & Exacerbated but not caused by smoke exposure – Associated with allergies – Obstruction is usually reversible with a beta-agonist – No defect in gas exchange – Associated diseases: Allergic rhinoconjunctivitis & Atopic dermatitis What's going on here?

Answer 46

Asthma