Embryology Flashcards
what germ layers form the respiratory system
endoderm (lining) mesoderm (lung tissue)
what is the embryological logical reason for the digestive and respiratory tracts being connected
as lung buds and trachea form from foregut which later become the esophagus
what are the common congenital defects of the resp system that develop in embryos
failure in separation of trachea and esophagus
what is an oesophageal atresia
when esophagus ends in blind ending pouch
what us the tracheosophageal fistula
communication point between trachea and esophagus
name the stages of lung maturation
embryonic, pseudoglandular, canalicular, saccular, alveolar
what happens in the embryonic stage of lung maturation
respiratory diverticulum forms. initial branching to give lungs, lobes and segments
what happens in the pseudoglandular stage of lung maturation
14 more generations of bronchioles
what happens in the canalicular stage of lung maturation
terminal bronchioles -> 2+ resp bronchioles -> 3-6 alveolar ducts
what happens in the saccular stage of lung maturation
terminal sacs form; capillaries close contact
what happens in the alveolar stage of lung maturation
alveoli mature
what two cell types form the alveoli and their function
cuboid and thin squamous epithelium, allows diffusion