Respiratory Embryology Flashcards
develops at 4 weeks
outgrowth of ventral wall of the foregut
respiratory diverticulum
5-16 weeks
All terminal bronchioles have formed, no respiratory bronchioles or alveoli; few blood vessels
Pseudoglandular stage
16-26 weeks
Respiratory bronchioles and alveolar ducts have formed, no type II cells (undifferentiated cuboidal epithelium), BV distant precluding gas exchange
Canalicular Stage
26-40 weeks
Alveolar sacs and type I/II cells develop; capillaries associated with alveoli
after 28 weeks, there is a decreased chance of respiratory distress syndrome on premature birth, sufficient lung functioning is possible and the newborn has a good chance of survival
Terminal Sac Stage
32 weeks - childhood
Functional maturity and postnatal growth; capillaries protrude into alveoli increasing gas exchange
Alveolar period
epithelium of the internal lining of the larynx, trachea, bronchi, and lungs including glands; alveolar epithelium
structures derived from endoderm
cartilaginous, muscular and CT components of the respiratory system = lamina propria, mural cartilage, mural smooth muscle, blood vessels, lymphatics
structures derived from splanchnic mesoderm
Small granule cells (Kulchitsky cells = specialized cells that regulate function locally via secretion of catecholamines and peptides)
structures derived from neural crest cells
most common cause of death in premature infants
results from functional immaturity of lungs when fetus is born before type II cells differentiate and produce surfactant
cyanosis, low PaO2, high PaCO2, tachycardia, grunting noises during breathing, clavicular depression, dense lungs on CXR, atelectasis
stall premature delivery, accelerate fetal lung development with glucocorticoids
supply O2 and articificial surfactant after birth
Respiratory Distress Syndrome
Hyaline Membrane Disease
