Respiratory Flashcards
What structures are included in the proximal conducting portion of the respiratory system?
nasal cavity, paranasal sinuses, nasopharyx and oropharynx, larynx
Where is the esophagus in relation to the conducting portion of respiratory system?
posterior
What kind of epithelium does the conducting portion of resp system have?
pseudostratified columnar with cilia (exceptions: olfactory area of nasal cavity oropharyx, parts of epiglottis and vocal cords)
What type of epithelium do the vocal cords have?
non-keratinized stratified columnar
What structures are included int the distal portion of the conduction respiratory system?
trachea, bronchi, bronchioles (last branch is the terminal bronchiole)
Structure of the trachea
hyaline cartilage (C-shaped partial ring) open posteriorly for expansion and contraction; trachealis (SM) in open part of the C
describe “typical” respiratory epithelium
pseudostratified columnar epithelium w/ cilia
describe more distal/smaller bronchi epithelium
gradual transition to simple columnar epithelium w/ cilia still apparent
describe bronchioles and more distal respiratory structure epithelium
epithelium changes simple low columnar –> cuboidal –> low cuboidal –> simple squamous (at level of gas exchange)
Types of cells in respiratory epithelium (5)
columnar cells w/ cilia “mucociliary escalator”, goblet cells, brush cells, neuroendocrine cells, basal stem cells
brush cells
in respiratory endothelium, have synaptic contact with afferent nerves
bronchus
trachea –> bronchi –> bronchioles; respiratory epithelium; cartilaginous plates maintain rigidity and prevent collapse
bronchiole
most proximal part of respiratory portion; transition ciliated simple columnar –> ciliated simple cuboidal; no cartilage, more SM and elastic fibers; no goblet cells but clara cells
clara cells
found in bronchioles; stem cells that divide and replace other ciliated cells; secrete GAGS (i.e. surfactin-type liquid that lowers surface tension and prevents bronchiole from collapsing on itself); may play detox role
draw a diagram of component transitions, characterizing frequency/type of epithelium, goblet cells, ciliated cells, glands, hyaline cartilage, SM, and elastic fibers from the trachea to alveoli
See slide 18 or 19