Embryology - Clinical aspects of congenital embryonic abnormalities Flashcards
What is the main determinant of the survival of newborn babies?
Their lung health
The esophagus gives rise to…
the tracheal bud (i.e. the trachea and the esophagus share a common ancestor)
In healthy development, the esophagus and the tracheal tube should…
completely separate (NO fusion)
The endoderm gives rise to…
- airways epithelium
- airway glands
- pulmonary epithelium
The mesoderm gives rise to…
- connective tissue
- cartilage
- smooth muscle
What is atresia?
When a luminal structure becomes blind-ended
85% of abnormalities of tracheal budding are…
???
What are the symptoms of esophageal atresia and tracheo-esophageal fistula?
- excess salivation
- respiratory distress
- choking on feeds
- maternal polyhydraminos
- baby cannot swallow amniotic fluid
How is a fistula usually detected?
The baby cannot swallow amniotic fluid, and the stomach is smaller than normal (because the baby is not swallowing amniotic fluid)
What is a bronchopulmonary foregut malformation?
It is a cystic remnant of the budding process of the trachea. It is found in the mediastinum. It makes the baby prone to infection.
What are the symptoms of bronchopulmonary foregut malformation?
Can be asymptomatic or cause acute or chronic aero-digestive tract symptoms
Histologically, what do you see in a bronchopulmonary foregut cyst
Both GI muscle pattern and ciliated columnar epithelium typical of respiratory airways.
By 24 weeks how many orders of branches have formed in the lungs?
17
How long does the alveaolar development period continue?
From 32 weeks of development to 8 years of life!
What happens during the canalicular period of development?
- Bronchi and terminal bronchioles become larger
- Lung becomes highly vascular
- Respiratory bronchioles and alveolar ducts develop
- Terminal saccules (primordial cavities) are now capable of gas exchange
What happens during the terminal saccular period?
- Increased number of terminal saccules
- TS epithelium…
What is the purpose of surfactant therapy?
When is the alveolar period I? When is the alveolar period II?
Alveolar period I: 32 weeks-birth
Alveolar period II: birth - 8 years
Factors necessary for normal lung development.
- Adequate thoracic space for lung growth
- fetal breathing movements
- adequate amounts of amniotic fluid
What is Potter’s sndrome?
No production of amniotic fluid, so lungs do not develop and the babies die of respiratory failure.
What is an aplastic lung? What is an aplastic lobe?
What is congenital lobar emphysema?
Failure of bronchial mesenchyme
Dysplastic bonchial cartilage collapses during expiration
Severe air trapping and hyperinflation of affected lobe
What is congenital pulmonary airways malformation (CPAM)?
A segment of the lung arrests in development early (in the pseudoglandular period). There is an overgrowth of bronchioles and a deficiency in the number of alveoli in the segment. The affected segment is cystic and glandular (adenomatoid).
Symptoms of CPAM are due to…
presence of a large non-functional mass or delayed infections
