NM705 EXAM 1 QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS VERIFIED
When does the canalicular period occur?
16-25 wks
What becomes larger in the lungs during the canalicular period?
- lumina of bronchi
- terminal bronchioles
What becomes highly vascular during the canalicular period?
- lung tissue
What happens to the terminal bronchiole by 24 wks during the canalicular
period?
- develops 2 or more respiratory bronchioles
What does each respiratory bronchiole divide into during the canalicular period?
- 3-6 tubular passage
- primordial alveolar ducts
When is respiration possible in fetal lung development?
- toward the end of canalicular period
what is occuring towards end of canalicular period
- thin-walled terminal sacs develop @ end of respiratory bronchioles
- lung tissue is vascular
Why is the development of the canalicular period important for a premature birth?
, - if born @ 24-26 wks can survive --> but often die d/t immature respiratory & other
systems
What happens in the terminal saccular period?
- many more terminal sacs develop
- epithelium thins
- capillaries begin to bugle
When does the terminal saccular period occur?
- btwn 24 wks & late fetal period
type II pneumocytes
- secrete pulmonary surfactant
type I pneumocytes
- are terminal sacs lined with squamous epithelial cells
what occurs in type I pneumocytes
- gas exchange
What is the blood-air barrier?
- intimate contact btwn epithelial & endothelial cells
What does blood-air barrier permit?
- adequate gas exchange for survival
What is surfactant?
- forms as monomolecular film on interior walls of alveolar sacs
What does surfactant do?
- counteracts surface tension forces --> facilitating expansion
What should be considered with Preterm infants lung development?
COMPLETE SOLUTIONS VERIFIED
When does the canalicular period occur?
16-25 wks
What becomes larger in the lungs during the canalicular period?
- lumina of bronchi
- terminal bronchioles
What becomes highly vascular during the canalicular period?
- lung tissue
What happens to the terminal bronchiole by 24 wks during the canalicular
period?
- develops 2 or more respiratory bronchioles
What does each respiratory bronchiole divide into during the canalicular period?
- 3-6 tubular passage
- primordial alveolar ducts
When is respiration possible in fetal lung development?
- toward the end of canalicular period
what is occuring towards end of canalicular period
- thin-walled terminal sacs develop @ end of respiratory bronchioles
- lung tissue is vascular
Why is the development of the canalicular period important for a premature birth?
, - if born @ 24-26 wks can survive --> but often die d/t immature respiratory & other
systems
What happens in the terminal saccular period?
- many more terminal sacs develop
- epithelium thins
- capillaries begin to bugle
When does the terminal saccular period occur?
- btwn 24 wks & late fetal period
type II pneumocytes
- secrete pulmonary surfactant
type I pneumocytes
- are terminal sacs lined with squamous epithelial cells
what occurs in type I pneumocytes
- gas exchange
What is the blood-air barrier?
- intimate contact btwn epithelial & endothelial cells
What does blood-air barrier permit?
- adequate gas exchange for survival
What is surfactant?
- forms as monomolecular film on interior walls of alveolar sacs
What does surfactant do?
- counteracts surface tension forces --> facilitating expansion
What should be considered with Preterm infants lung development?
