Developmental Aspects of Lung Disease Flashcards
What are the five stages of lung morphogenesis?
Embryonic Pseudo-glandular Canalicular Saccular Alveolar
What happens during postnatal lung growth?
Alveolar separation continues and then the alveolar dimensions increase
Name the 2 types of lunge development
Organogenesis and differentiation
When does surfactant begin to be produced?
12-14 weeks
What happens in the embryonic stage?
Tubular growth from the foregut. Formation of the trachea and the primary bronchial tubule
What happens during the pseudo-glandular stage?
The lobes of the lungs are formed as well as the rest of the bronchial tree and the acinus
What happens during the canalicular stage?
The final aspects of the lung periphery are formed as well as the air-blood barrier so that gas exchange is possible at the end of this period.
What happens during the sacular stage?
There is expansion of air spaces and surfactant is produced
What happens in the alveolar stage?
The alveoli separate to multiply and this continues after birth
What problems can arise during the alveolar stage?
Tracheal, laryngeal stenosis
Pulmonary agenesis
Tracheo-oesophageal fistula
What problems can arise during the pseudoglandular stage?
Pulmonary sequestration
Cystic adenomatoid malformation
Cyst formation
Describe diaphragm development
A variety of primitive tissue contribute to the formation of the diaphragm and it is completed by around 18 weeks
What are the results of a diaphragmatic hernia?
The heart can be pushed over across to the right side of the thorax
Pulmonary hypoplasia
Persistant pulmonary hypertension
What is eventration?
When the diaphragm isn’t as muscular as it should be so hasn’t formed correctly and so bulges up into the thoracic cavity
What are the functional changes in the lungs at birth?
Changes from a fluid secreting organ to a fluid absorption organ
Pulmonary vasodilatation
