Respiratory Embryology Flashcards
The respiratory system starts as a median outgrowth know as the?
Laryngotracheal groove
What forms the pulmonary epithelium and glands of larynx, trachea and bronchi?
Endoderm of laryngotracheal groove
What forms the CT, cartilage, and smooth muscle of the respiratory system?
Splanchnic mesoderm from lateral plate
The laryngotracheal groove will evaginate to form?
When this new structure elongates it’s invested with?
1) Laryngotracheal diverticulum (lung bud)
2) Splanchnic mesenchyme
As the tracheoesophageal folds develop, they fuse to from?
What is this structures role?
Around what time does this happen?
1) Tracheoesophageal septum
2) Prevents aspiration during eating/drinking
3) End of 5th week
The foregut is formed during?
It gives rise to?
1) Week 4
2) Upper GI and lungs
During the development of the larynx, mesenchyme of 4th and 6th pairs of PAs (NCC derived) creates the?
Cartilages
During the development of the larynx, mesenchyme produces?
What does this structure do?
1) Paired arytenoid swellings
2) Convert primordial glottis into a T-shaped laryngeal inlet
During the development of the larynx, recanalization occurs by the?
Laryngeal ventricles form during recanalization and are bounded by folds of mucous membrane to form?
1) 10th week
2) Vocal folds (cords) and vestibular folds
What does the epiglottis develop from?
Hypopharyngeal eminence produced from endoderm of 3-4th PAs
In neonates, the epiglottis is in contact with?
What does this result in?
1) Soft palate
2) Separates respiratory and digestive tracts during nursing
What allows you to start feeding a child more liquid and solid foods?
The laryngeal descent over the first 2 years
Laryngeal atresia is a rare birth defect that results from?
Failure of recanalization of the larynx
Laryngeal atresia can result in what physical presenting symptoms?
How is laryngeal atresia treated?
1) Congenital high airway obstruction syndrome (CHAOS)
2) Endoscopic dilation of the laryngeal web
What fails in a tracheoesophageal fistula?
In what week does the failure occur?
What causes them?
What do they lead to?
1) Tracheoesophageal septation
2) Week 5
3) Failure of foregut endoderm to proliferate rapidly
4) Food will aspirate into lungs
What are polyhydramnios?
What is it caused by?
1) Excess amniotic fluid
2) Esophageal atresia or tracheoesophageal fistula
During lung development the distal end of laryngotracheal diverticulum enlarges to form?
The bud grows ventrocaudal and bifurcates to form?
They grow in the?
When does it branch?
1) Respiratory bud
2) Primary bronchial buds
3) Pericardioperitoneal canals
4) 5th week
The branching pattern of the lung endoderm is regulated by?
Splanchnic mesenchyme
The visceral pleura is what portion of lateral plate mesenchyme?
The parietal pleura is what portion of lateral plate mesenchyme?
1) Splanchnic
2) Somatic
During the pseudoglandular stage of lung maturation, what part of the lung is developed?
What weeks does the pseudoglandular stage fall under?
1) Terminal bronchioles
2) 5-17 weeks
What forms during the canalicular stage of lung maturation?
What weeks does the canalicular stage fall under?
1) Respiratory bronchioles and primordial alveolar
2) 16-25 weeks
What forms during the terminal sac stage of lung maturation?
What weeks does the terminal sac stage fall under?
1) Type I/II pneumocytes appear
2) 24 weeks to birth
What forms during the alveolar stage of lung maturation?
What weeks does the alveolar stage fall under?
1) Mature alveoli and capillaries
2) 32 weeks to 8 years
Can the fetus survive in the following stages of lung maturation:
1) pseudoglandular stage
2) canalicular stage
3) terminal sac stage
4) alveolar stage
1) No
2) Some can
3) Yes
4) Yes
