Histology Flashcards
What tissue lines the initial part of the nasal cavity?
Keratinised stratified squamous epithelium
What lines the deeper part of the nasal cavity?
Initially, keratin is lost
Deeper, it changes to respiratory epithelium
What is respiratory epithelium?
Pseudostratified ciliated columnar epithelium with goblet cells
What layer is underneath the respiratory epithelium?
Lamina propria - connective tissue
What is contained within the lamina propria?
Seromucous glands
Rich venous plexus which can quickly engorge with blood to ‘block’ the nose
What happens to the cartilidge ‘C’s that surround the trachea as you go further down the respiratory tree?
Change to irregular cartilidge discs in the bronchi
Cartilidge becomes more and more sparse
No longer present in bronchioles and alveoli
What does the lamina propria of the bronchioles consist of?
Smooth muscle, elastic and collagenous fibres
What are the terminal bronchioles lined with?
Cuboidal ciliated epithelium and contain non-ciliated Clara cells
What are the roles of Clara cells?
Stem cells
Detoxification
Immune modulation
Surfactant production
What is the low cuboidal epithelium of the terminal bronchioles replaced with in the alveoli?
Discontinuous squamous type 1 alveolar cells
What are type 1 alveolar cells?
Simple squamous epithelium that lines the alveolar surfaces covering over 90% of the alveolar surface
These cells provide a barrier of minimal thickness that is permeable to gases
What are type 2 alveolar cells?
Release surfactant which covers the epithelial lining of the alveoli
