Developmental aspects of lung disease Flashcards
What are the five stages of lung morphogenesis
- Embryonic
- Pseudo-glandular
- Canalicular
- Saccular
- Alveolar
What two stages are organogenesis
Embryonic
Pseuglandular
What occurs in the stage embryonic
The trachea develops form a single tube
What does the primary bronchial tubules contain in the embryonic stage
Fluid filled
What stage does a primitive looking lung form
Psnedo-glandular
What can be seen in the pseudo-glandular stage
Lobes form Formation of major airways Formation of bronchial tree Birth of the acinus (a region of the lung supplied with air from one of the terminal bronchioles)
Is gas exchange possible in the pseudo-glandular stage?
No
What 3 stages are in the differentiation stage of lung morphogenesis
Canalicular
Saccular
Alveolar
What change occurs in the canalicular stage
Epithelial differentiates
Formation of air blood barrier - SURFACTANT
When does gas exchange become available
at the end of the canalicular stage
What also occurs in the saccular stage and alveolar stage
expansion of air spaces with saccules and alveoli
What continues postnatal lung growth?
alveolar seperation
What happens to the lungs with increasing age
loose lung function (after peaking)
What gives the biggest decline in loosing lung function
smoking
What lung abnormalities can occur in the embryonic stage
tracheal, laryngeal stenosis -
pulmonary agenesis
tracheo-oesophageal fistula
What is tracheoesophageal fistula
is an abnormal connection (fistula) between the esophagus and the trachea
What is tracheal, laryngeal stenosis
Narrowing of the trachea
What is pulmonary agenesis
Failure of lung development
What is the lung abnormalities than can occur in the Pseudoglandular stage
pulmonary sequestration
cystadenomatoid malformation
cyst formation
What is pulmonary sequestration
nonfunctioning mass of normal lung tissue located in the lower respiratory tract
What is Cystadenomatoid malformation
when an entire lobe of lung is replaced by a non-working cystic piece of abnormal lung tissue
When does diaphragm closure occur
18 weeks
What is two examples of diaphragm abnormalities
Diaphragmatic hernia
Eventration
What is eventration of the diaphragm
protrusion of contents of the abdomen through a defect or weakness in the abdominal wall
What is Diaphragmatic hernia
an abnormal opening in the diaphragm
What is the effects of Diaphragmatic hernia
pulmonary hypoplasia
leading to persistent pulmonary hypertension
Define Pulmonary hypoplasia
incomplete development of the lungs, resulting in an abnormally low number or size of bronchopulmonary segments or alveoli
Where is Diaphragmatic hernia more common and why?
On the left side as the liver on your right can potentially plug the hole
What two functional changes happen at birth
Change from fluid secretion of saline to breathing in air
Pulmonary vasodilatation
What occurs in Transient tachypnea in new borns
there hasn’t been a rapid shift from fluid secretion in the lungs and the baby is struggling to breathe in air
What is the name of a surfactant deficiency
Hyaline Membrane Disease (RDS)
What is the treatment for surfactant deficiency
Antenatal glucocorticoids - stimulate surfacant
Surfactant replacement
Oxygen
CPAP - keep airways open with positive pressure
Mechanical ventilation
What can chronic neonatal diseases increase the risk of
severity bronchiolitis
asthma
future COPD
What can be a cause of surfactant deficiency
Being born to premature
What features of antental increase the risk of COPD development
in utero nicotine exposure - mother smoking
nutrition
low birth weight/prematurity (antenatal steroids)
micronutrients/vitamins
What features of postnatal increase the risk of COPD development
infection - reduce lung function
growth - don’t grow as well
environmental pollution e.g. tobacco smoke
micronutrients/vitamins
What is the affect of Antenatal programming, environmental exposures or gene interactions
Lung remodelling
Does low lung function improve with age?
No
