histology Flashcards
mucosa
inner region w/ resp epithelium, lamina propria
submucosa
middle region w/ seromucous glands
adventitia
outer region of trachea, hyaline cartilage
lamina propria
thin connective tissue below basement membrane
chondrocytes
cartilage cells central to hyaline cartilage
trachealis muscle
smooth muscle in trachea, bridges gaps in cartilage
diff b/w primary bronchiole and bronchus
no cartilage and less glands, increased SM in primary bronchiole
alveolar ducts
linear passages continuous w/ respiratory bronchioles, most distal portion w/ SM cells (appear as knobs)
alveolar sacs
outpouchings of numerous alveoli
type I pneumocytes
thin cytoplasm, cover 95% of alveolus, form half of blood gas barrier
type II pneumocytes
cuboidal, near septal intersections, synthesize surfactant and divide/regenerate to both pneumocyte types
lamellar bodies
present in type II pneumocytes cytoplasm, contain phospholipids that contribute to surfactant
blood gas barrier
alveolus (type I) cytoplasm and capillary endothelium are on opposite sides of shared basement membrane
epithelium changes moving distally
pseudostratified ciliated columnar for bronchus until terminal bronchioles, transition to cuboidal through respiratory bronchioles then simple sqamous in alveoli
basal cells (short cells)
rest on basal lamina, dont extend to lumen
location and role of club cells
primary and terminal bronchioles, main cell in respiratory bronchioles
divide and can differentiate to ciliated, secrete glycosaminoglycans (surfactant component) metabolize toxins w/ cyt p450
primary bronchioles
1mm or less, ciliated w/ goblet cells in epithelium (transitioning to ciliated cuboidal w/ club cells)
no glands or cartilage, but do have SM
terminal bronchioles
most distal part of conducting portion, less than 0.5 mm
simple cuboidal w/ mostly club cells and no goblet cells
no glands or cartilage, some SM
respiratory bronchioles
transition to respiratory portion, simple cuboidal w/ mostly club cells and some interruptions by alveoli simple sqamous
alveolar macrophages structure and fn
dust cells, large and irregular w/ vacuolated cytoplasm, sometimes w/ indented nucleus
remove dust, inhaled particles- migrate to bronchioles after filling then to oropharynx and are swallowed, expectorated, or removed by lymphatics
secrete elastase
describe surfactant structure
phospholipids and 4 proteins, has a lower aqueous phase and a superficial lipid phase
B and C proteins required for physiology, A and D for immunity
