Developmental Aspects of Lung Disease Flashcards
During growth and development of the lung, what processes/systems are essential for healthy lungs?
- morphogenesis
- surfactant system
- postnatal lung growth
Abnormalities of growth and development of the lung can lead to what?
- congenital lung disease
- hyaline membrane disease
What are the 5 stages of lung morphogenesis?
- Embryonic
- Pseudo-glandular
- Canalicular
- Saccular
- Alveolar
During what stage of lung morphogenesis does the larygo-tracheal groove grow forward, budding out to form the primitive trachea?
Embryonic (3-8 weeks)
Gas exchange becomes possible towards the end of what stage of lung morphogenesis?
Canalicular
What can be seen in the pseudo-glandular stage of lung morphogenesis?
Any major airway abnormalities
- small airways
- increased branching
- blood vessels a large distance from airways
What happens to the blood vessels in the Canalicular stage of lung morphogenesis?
They move closer to airways allowing gas exchange
As the alveolar stage of lung morphogenesis continues, the number of alveoli
increases
The continuation of alveolar separation in postnatal lung growth provides
a large surface area to allow gas exchange
Expansion of air spaces occurs in which stage of lung morphogenesis?
Saccular
In the embryonic stage of lung morphogenesis what structural abnormalities, which could indicate congenital lung disease, can be seen?
- stenosis (tracheal/laryngeal)
- pulmonary agenesis
- tracheo-oesophageal fistula
What abnormalities can be seen in the pseudoglandular stage of lung morphogenesis?
- pulmonary seqestration
- cystadenomatoid malformation
- cyst formation
What are the two common diaphragmatic abnormalities?
- diaphragmatic hernia
- eventration (where most of diaphragm is raised)
What functional changes occur in the lungs at birth?
- change from fluid secretion to fluid absorption
- pulmonary vasodilatation
What may occur in a newborn baby whose lungs have not yet transitioned from fluid secretion to absorption?
Tachypnoea (rapid breathing)
What is the function of surfactant in the lungs?
Stabilises alveoli and promotes gas exchange
Surfactant deficiency can cause what neonatal lung disease?
Hyaline membrane disease
When does Hyaline Membrane Disease occur?
In premature babies where surfactant hasn’t been formed so airways can collapse
Chronic neonatal lung disease is suspected to make children more susceptible to what condition in adult life?
COPD
What can lead to adult COPD in the antenatal stage?
- in utero nicotine exposure
- low nutrition, micronutrients and vitamins
- low birth weight/prematurity
People with normal, healthy lungs will experience decreased lung function when?
With decreased age
Accelerated decline in lung function can be seen in who?
- Smokers
- Premature babies
- Children exposed to second hand smoke
- Children who have experienced lung insult
If long term smokers quit smoking, will there be any effect on their lung function?
Lung function will still decrease faster than that of a non-smoker, but will improve compared to those who keep smoking
What is the main cause of COPD?
Heavy smoking
Low lung function at birth increases the risk of developing what?
COPD