Histology

Question 1

Epithelium progression

Answer 1

1. nasal cavity to the bronchi, is lined by pseudostratified columnar ciliated epithelium 2. low columnar > cuboidal > simple bronchioles are lined by simple columnar to the cuboidal epithelium 3. alveoli possess a lining of thin squamous epithelium that allows for gas exchange

Question 2

Features of Trachea

Answer 2

Cartilage ring, with smc connection (trachealis)

Question 3

Extrapulmonary to Intrapulmonary

Answer 3

identicak to trachea but smaller lumen and thinner wall, progression of cartilage plates, smc only where cartilage is deficient distinct smc layer between mucosa and submucosa, goblet and glands are reduced. Folding of mucosa.

Question 4

Bronchiole histo features

Answer 4

-Clara cells (arise from T2. pneumocytes) = surfactant and regenration - DIAGNOSTIC: NO. CARTILAAGE OR GLANDS - low columnar/cuboidal/simple epithelia

Question 5

Alveolar histological features

Answer 5

• elastic dominant connective tissue - dust cell, type 1 pneumocyte, type 2 pneumocyte