Embryology Flashcards
Stages of lung development
Embryonic, Pseudoglandular, Canalicular, Saccular, Alveolar
Embryonic stage weeks of development
4-7 weeks
Initial week of lung bud development from respiratory diverticulum
Week 4
Pseudoglandular stage weeks of development
5-17 weeks
Errors in this stage can lead to tracheoesophageal fistula
Embryonic stage
Canalicular stage weeks of development
16-25 weeks
Stage airways increase in diameter and respiration capable
Canalicular stage
Saccular stage weeks of development
Week 26-birth
Number of alveoli at birth
20-70 million
Leads to increased vascular resistance through gestation
Aspiration and expulsion of amniotic fluid
Process that leads to adult alveoli from terminal sacs
Secondary septation
Stage terminal sacs separated by primary septation
Saccular stage
Stage terminal bronchioles develop
Pseudoglandular stage
Stage of lung development characterized by secondary septation
Alveolar stage
Stage pneumocytes develop
Saccular
Pulmonary hyperplasia resulting from diaphragmatic hernia typically occurs on what side of diaphragm
Left side
Bilateral renal agenesis results in what pulmonary condition
Pulmonary hypoplasia
Caused by abnormal budding of the foregut and dilation of terminal or large bronchi
Bronchogenic cysts
Discrete, round, sharply defined, fluid filled densities on CXR causing airway compression or recurrent pulmonary infections
Bronchogenic cysts
Non-ciliated, low-columnar/cuboidal cells with secretory granules located in small airways
Clara cells
Function of Clara cells
Secrete component of surfactant, degrade toxins, reserve cells
Law of Laplace
P = 2(surface tension)/radius
Type of epithelium on type 1 pneumocytes
Squamous epithelium
Week surfactant synthesis begins
Week 26
Week mature levels of surfactant achieved
Week 35
Respiratory cells that proliferate in presence of toxins
Clara cells
Function of surfactant
Prevent collapse of alveoli during exhalation
Surfactant deficiency treatment before birth
Maternal steroids
Surfactant deficiency treatment after birth
Exogenous surfactant to infant
