Resp 1 Flashcards
5 Stages of lung development
- Embryonic Period
- Pseudo - glandular period
- Canalicular period
- Saccular and alveolar period
- Post natal period
4 points of embryonic period
- Respiratory diverticulum develops as an evagination from the foregut
- Primitive trachea forms lung buds that fork to form primitive bronchi
- Branching produces lobular bronchii
- Lobes are surrounded by mesenchyme which will form visceral pleura
What does the respiratory diverticulum devlop as?
An evagination from the forgut
What are lobes in the embryonic period surrounded by?
Messenchyme which will form the visceral pleura
What doe mesenchyme which is in direct contact of bronchi develop into?
Visceral Pleura
What do lung bud branchings form?
Bronchi which develop into lobular bronchi
3 Points to pseudo glandular period
- Lobular bronchi give rise to segmental bronchi that undergo many bifurcations
- Terminal bronchioles form
- Cell differentiation
What do lobular bronchi give rise to in pseudo glandular period?
Segmental bronchi that undergo many bifurcations
What stage do terminal brochioles form?
Pseudo-glandular period
What are 4 types of cells that differentiate in pseudo glandular period?
Epithelial cells
Cartilage
Submucosal Glands
Smooth Muscle
Four points to canalicular period
- Lumin of bronchi and broncioles enlarge, increased vascularization
- Continued bifurcations and formation of terminal and respiratory bronchioles
- Formation of areas of the lungs that will be involved in gas exchange
- Respiratory bronchioles form canaliculi and terminal saccules
What allows for increase vascularization during canalicular period?
Lumina of bronchi and bronchioles enlarge
During what period do respiratory bronchioles form canaliculi and terminal saccules?
Canalicular period
What occurs durring saccular and alveolar periods?
Epithelium of primitive alveoli differentiate into type I and type II alveolar cells
During which period are type I and type II alveolar cells formed?
Saccular and alveolar periods
