Respiratory Flashcards
What is the function of Type I pneumocytes?
gas exchange
Type I pneumocyte structure
flat cells that cover 95-97% of the alveolar surface
What are the alveolar cell types?
Type I pneumocytes, Type II pneumocytes, Alveolar macrophages
Type II pneumocyte function
2 functions:
- release surfactant
- proliferate/regenerate in response to injury-precursor for both Type I and Type II pneumocytes
Type II pneumocyte structure
5% of the alveolar surface, made up of cuboidal cells
(cuboidal cells secrete surfactant)
Surfactant actions
decrease surface tension, alveolar collapse, lung recoil
increase compliance
What is surfactant composed of?
lecithins, mainly dipalmitoylphosphatidylcholine (DPPC)
When does the synthesis of surfactant occur?
it begins at 20 weeks gestation and achieves mature levels at 35 weeks of gestation
What is important for fetal surfactant synthesis and lung development and will be given to moms in preterm labor?
glucocorticoids
What is derived from fetal monocytes during lung development?
alveolar macrophages
What are the principal cells involved in clearing inhaled foreign particles from the terminal respiratory units?
alveolar macrophages-immune function
When would hemosiderin-laden macrophages be found?
pulmonary edema or alveolar hemorrhage
hemosiderin is
a brown iron-containing pigment usually derived from the disintegration of extravasated red blood cells
Law of Laplace says
alveoli have increased tendency to collapse on expiration as radius decreases
The conducting zone is made up of:
trachea, bronchi, bronchioles, terminal bronchioles
