Developmental Aspects of Lung Disease Flashcards
What is the first part of the respiratory system that develops?
The trachea
What happens during the embryonic stage of lung development?
The trachea branches off from the laryngo-tracheal groove and the mesoderm begins signalling to the surrounding cells
What happens during the pseudo-glandular stage of lung development?
The lobes of the lung, most of the major airways and primitive acinar structures have formed
What happens during the canalicular stage of lung development?
Smaller and smaller tubules are formed creating a thin air to blood barrier
What happens during the alveolar stage of lung development?
The alveoli are formed and the lungs have a large surface area
How does lung development progress after birth?
Alveolar septation continues and alveolar dimensions increase
What happens during the saccular stage of lung development?
The air spaces expand and surfactant is detectable in amniotic fluid
At what point are most features of abnormal lung development detected?
During a fetal ultrasound
What features of abnormal lung development can be seen in the newborn period?
Tachypnea and respiratory distress
What features of abnormal lung development are seen in childhood?
Stridor/wheeze, recurrent pneumonia or an accidental finding
What are the symptoms of tracheo-bronchomalacia?
Barking/seal-like cough, early-onset/recurrent croup, breathlessness on exertion and stridor/wheeze
What is the management of tracheo-bronchomalacia?
Airway clearance physiotherapy and antibiotics
What medication should not be given to a patient with tracheo-bronchomalacia?
Bronchodilators as these can cause further closure of the airway
What condition is associated with a surfactant deficiency in new-borns?
Infant respiratory distress syndrome
What are the causes of chronic neonatal lung disease?
Antenatal infection, barotrauma, oxygen toxicity, PDA and genetic factors
What is remodelling?
Alteration of structure following an external influence
What are the effects of pre-natal nicotine exposure on the lungs?
Lung hypoplasia, reduced alveolarisation, reduced lung function, increased incidence of wheeze syndromes and increased susceptibility to infection
What are the effects of chronic inflammation on the lungs?
Increased bronchial responsiveness, increased mucus secretion, airway oedema and airway narrowing
What are the features of a diaphragmatic hernia
- L>R
- Pulmonary hyperplasia
- Persistent pulmonary hypertension
What are the functional changes in the lungs that happen at birth
- Change from fluid secretion to fluid absorption
- Transient tachypnea of newborn is associated with C sections but resolves within 24-48hrs
What are the treatment options for hyaline membrane disease (surfactant deficiency)
- Antenatal glucocorticoids
- Surfactant replacement
- Supportive
What are the causes of chronic neonatal lung disease
- Antenatal infection
- Barotrauma/oxygen toxicity
- PDA
- Genetic
Name the antenatal causes of adult lung disease
- In utero nicotine exposure
- Fetal infection
- Maternal nutrition
- Low birth weight/prematurity
- Maternal micronutrients/ vitamins
Name the postnatal causes of adult lung disease
- Infection
- Growth
- Environmental tobacco smoke
- Environmental pollution
- Micronutrients/vitamins
How does remodelling happen in asthma?
- Chronic inflammation
- Increased bronchial responsiveness
- Increase mucus secretion
- Airway oedema
- Airway narrowing
