chapter 1 fetal lung development Flashcards
what are the fetal lung development requirements
adequate surface area, pulmonary vascular systems ability to transport blood through the lungs, structure and elasticity
stages of lung development
embryonal pseudoglandular canalicular saccular alveolar
how long is the embryonal stage
week 1 - 8
when is the pseudo glandular stage
week 8-16
what lung developments occur during the pseudo glandular stage
conducting airways develop, pattern of lung structure is formed, cilia goblet cells, and mucus glands are formed, the epiglottis and the membrane that separates oropharnx is formed
when is the canalicular stage
week 17-26
what stage does fetal viability occur in and what week
canalicular stage week 22
what is developed (lungs) during week 20-22
type 1 and II epithelial cells, immature surfactant, and smooth muscle in conducting airways
when is the saccular stage
week 27 - 35/36 weeks & post term
when are alveoli seen
week 32
what occurs in the lungs during the saccular stage
alveoli epithelium and pulmonary capillaries merge, alveoli increase in number and size, mature surfactant
what occurs during alveolar stage
at birth alveoli are 20-150 million, and continue development up to age 8 increasing in size until growth of chest wall is complete
what factors affect lung growth
hypoxia, starvation, hyperoxia
what is pulmonary hypoplasia
lack of alveoli, not enough airways, olighydramnios (not enough amniotic fluid)
what can cause pulmonary hypoplasia
diaphragmatic hernia
