The Lung Morphology

Question 1

ALI Morphology

ACUTE EXUDATIVE stage

Answer 1

> Lungs are heavy, firm, red and boggy
> Congestion
> Interstitial and intraalveolar edema
> Inflammation
> Fibrin deposition
> Diffuse alveolar damage
> Alveolar walls - waxy hyaline memnbranes
> Fibrin-rich edema fluid mixed with remnants of necrotic epithelial cells

Question 2

ALI Morphology

PROLIFERATIVE/ORGANIZING stage

Answer 2

> Type II pneumocytes proliferate
Granulation tissue in alveolar walls and spaces
***Fibrotic thickening (scarring) ensues (LATE Fibrotic stage)

Question 3

Characteristic histologic finding of Acute Respiratory Distress Syndrome (ARDS)

Answer 3

> Hyaline membranes lining alveolar walls
Edema
Scattered neutrophils and macrophages
Epithelial necrosis

Question 4

Morphology of emphysema

**Characteristic of Irregular emphysema?

Answer 4

Apical blebs or bullae

Question 5

Morphology of emphysema

Answer 5

> Abnormally large alveoli are separated by thin septa with focal centriacinar fibrosis
Loss of attachments
Large pores of Kohn = Floating/protruding septa with a club-shaped end
Decrease in the capillary bed area
Larger abnormal airspaces

Question 6

Morphology of Chronic Bronchitis

Answer 6

> Hyperemia
> Swelling
> Edema of mucus membranes
> Excessive mucinous or mucopurulent secretions
> Heavy casts ot secretions and pus

Question 7

Characteristic microscopic features of Chronic Bronchitis

Answer 7

> Chronic inflammation of the airways
Thickening of the bronchial wall due to smooth muscle hypertrophy
Deposition of extracellular matrix in the muscle layer
Peribronchial fibrosis
Goblet cell hyperplasia
Enlargement of the mucus-secreting glands of trachea and bronchi
Bronchiolitis obliterans

Question 8

Ratio of the thickness of the mucous gland layer to the thickness of the wall between the epithelium and the cartilage

Answer 8

Reid index

Normal = 0.4

Question 9

Reid index in Chronic bronchitis

Answer 9

Increased