histology and embryology Flashcards
What is the function of type 2 alveolar cells?
produce surfactant
What is the function of type 1 alveolar cells?
blood-air barrier
What stage of lung maturation occurs between week 36 -early childhood? And what happens?
stage- alveolar
what happens-alveoli mature
What stage of lung maturation occurs between 28-36 weeks? And what happens?
stage-sacular
what happens-terminal sacs form and capillaries establish close contact
What stage of lung maturation occurs between 16-28 weeks?
Canalicular
What stage of lung maturation occurs between 6-16 weeks?
Pseudoglandular
What stage of lung maturation occurs between 26 days-6 weeks?
embryonic- initial branching to give lungs, lobes and segments
Where did the respiratory system grow out of?
layrngopharynx
Where does the lining of the trachea and bronchial tree come from?
Endoderm (all other lung tissue comes from the visceral mesoderm)
What are alveolar macrophages also known as?
dust cells
What 3 type of cells are alveoli lined with?
- type 1 alveolar cells
- type 2 alveolar cells
- dust cells
What are clara cells?
non ciliated club cells
What are the functions of clara cells?
surfactant production
immune modulation
stem cell
detoxification
What are the terminal bronchioles lined with?
cuboidal ciliated epithelium and contain clara cells
What lines the bronchi?
respiratory epithelium
Is there cartilage in the bronchi?
yes- irregular shaped cartilage plates
What change occurs to the epithelium in the bronchioles?
the epithelium changes from columnar to cuboidal as you progress down the tree
What lines the trachea?
- respiratory epithelium (until it divides)
2. 15-20 C shaped cartilage
What lines the larynx( except the vocal cords)?
respiratory epithelium
What lines the vocal cords?
stratafied squamous epithelium
What lines the orophraynx?
non-keratinised stratified squamous epithelium
What lies underneath the respiratory epithelium (in the nasal cavity?)
Lamina Propria
What epithelium lines the roof of the nasal cavity?
olfactory epithelium?
As you go deeper into the nasal cavity what change happens regarding the epithelium?
The initial part is lined by keratinised stratified squamous epithelium and as you go deeper the keratin is lost and it becomes pseudostratified ciliated columnar epithelium with goblet cells.
