Developmental Aspects of Lung Disease Flashcards
What are the 5 stages of lung morphogenesis?
- Embryonic
- Pseudo-glandular
- Canalicular
- Saccular
- Alveolar
What 2 stages fall into organogenesis?
- Embryonic
- Pseudo-glandular
What 3 stages fall into differentiation?
- Canalicular
- Saccular
- Alveolar
What post-natal lung growth is there?
- Alveolar separation continues
- Continuation in the increase of numbers of alveoli
- Airways double in size
What occurs during the embryonic and pseudo-glandular stages?
- Formation of major airways
- Formation of bronchial tree and portions of respiratory parenchyma
- Birth of the acinus
What occurs during the canalicular stage?
- Last generations of the lung periphery formed
- Epithelial differentiation
- Air-blood barrier formed
What occurs during the saccular stage?
- Expansion of air spaces
- Surfactant detectable in amniotic sac
What occurs during the alveolar stage?
Secondary septation
What can be seen at the embryonic stage?
Lung buds and main pulmonary arteries
Trachea and main bronchi
What can be seen at the pseudo-glandular stage?
All conducting airwys and accompanying vessels form, wall structure and epithelial cells differentiate
What can be seen at the canalicular stage?
Respiratory airways form, blood-gas barrier thins, surfactant appears.
Respiratory bronchiole
Alveolar ducts
What can be seen at the saccular-alveolar stages?
Saccules and then alveoli appear
What congenital lung diseases can occur at the embryonic stage?
- Tracheal, laryngeal stenosis
- Pulmonary agenesis
- Tracheo-oesophageal fistula
What is a trachea-oesophageal fistula?
An abnormal connection between the oesophagus and trachea
What congenital lung diseases can occur at the pseudo-glandular stage?
- Pulmonary sequestration
- Cystadenomatoid malformation
- Cyst formation
What are the forms of pulmonary sequestration?
- Extralobular sequestration
- Innerlobular sequestration
How does the diaphragm develop?
- Develops from a variety of primitive tissues
- Closure by 18 weeks
What is a diaphragmatic hernia?
Bowel has migrated up into the chest
What is commonly found with diaphragmatic hernia?
- Occurs more on the left side than the right
- Pulmonary hypoplasia
- Persistent pulmonary hypertension
What is eventration of the diaphragm?
Abnormal elevation of one side of the diaphragm
What functional changes take place at birth?
- Change from fluid secretion to fluid absorption
- Pulmonary vasodilation
What does transient tachypnea cause in newborns?
Wet lungs
What does surfactant do?
Stabilises alveoli and promotes gas exchange
What are other names of surfactant deficiency?
- Hyaline membrane disease
- Infant Respiratory Distress Syndrome
What is the treatment for IRDS?
- Antenatal glucocorticoids
- Surfactant replacement
- Oxygen
- CPAP
- Mechanical ventilation
If a child does not respond to IRDS treatment what can occur?
- Chronic neonatal lung disease (BPD, CLDP)
- Increased severity bronchiolitis
- Asthma
- Future COPD
What are the antenatal origins of COPD?
- In utero nicotine exposure
- Nutrition
- Low birth weight/ prematurity
- Micronutrients/ vitamins
What are the post-natal origins of COPD?
- Infection (Barker hypothesis)
- Growth
- ETS
- Environmental pollution
- Micronutrients/ vitamins
What rare the origins of COPD all influenced by?
Gene-environment interactions
What does the Fletcher Peto Diagram show?
The effects of smoking on rate of decline in FEV
