Respiratory System Flashcards
The respiratory system is divided into what two portions and their major functions
Conducting portion: cleanse and humidify the air
- nasal cavity, nasopharynx, larynx, trachea, bronchi, bronchiole, terminal bronchiole
Respiratory portions: gas exchange
- respiratory bronchiole, alveolar duct, alveoli
Respiratory epithelium makes up most of the conducting portion -
What kind of epithelium is it?
Ciliated pseudostratified columnar epithelium
At least 5 types of cells that all touch the basement membrane:
Ciliated columnar, Goblet cells, Brush cells, Small granule cells, Basal cells
Where would you find things like glands and cartilage here?
Lamina propria
What is the purpose of the cilia?
Help move mucus and debris out of the respiratory tract
What are the black arrows pointing at here?
What is its function?
Goblet cells produce mucin (becomes mucus when mixed with water to trap particulates)
- NO cilia
- Not as abundant as the ciliated columnar cells, but can be very abundant in some areas
- Bulging apical surface filled with granules of mucin glycoproteins –> light apperance
What cell type in respiratory epithelium is
- columnar
- short microvilli
- chemosensory receptors resembling gustatory cells
- afferent nerve endings on basal surface
Brush cells gives you gustatory sense and afferent nerve endings
(Don’t have to identify them bc they only make up 3%)
What cell type is
- part of the diffuse neuroendocrine system
- contains many dense core granules
Small granule cells
(don’t have to identify, either; just as rare as brush cells)
Basal cells identification & function
-
Small rounded cells on basement membrane
- DO NOT extend into the lumen
- Nuclei are basally located
- Stem cell that gives rise to other cell types
Where is olfactory epithelium found?
What is its function?
Within the epithlium overlying the superior nasal conchae
Gives you sense of smell
What kind of cells make up olfactory epithelium?
What is in its lamina propria?
- Supporting cells - columnar cells w/ microvilli
- Olfactory cells - bipolar neurons
- Basal cells - stem cells for the other cells
In the lamina propria, there are bowman’s glands and nerve tissue bundles
Why is there NO MUCUS overlying the ciliated portion of olfactory epithelium?
No goblet cells!
What cell type is the black arrows pointing at? What is their function?
Supporting cells forms a line of nuclei near the luminal surface
Have ion channels for olfactory function and olfactory neuron survival
What cell type is this?
Olfactory cells (bipolar neurons)
Nuclei are right below the supporting cells
What cell type is this?
Basal cells
adjacent to teh basement membrane of the olfactory epithelium
The lamina propria of olfactory epithelium contains what 2 significant structures?
What is this a scanning EM of?
The apical/dendritic end of an olfactory neuron with ~a dozen basal bodies from which long cilia project into the overlying aqueous layer
Glands surrounding the neuron constantly bathe the cilia
Olfactory neuron functioning steps
- Chemoreceptors on cilia axonemes respond to odoriferous substances
- Action potential goes down an axon
- Axon leaves the epithelium and unites in the lamina propria as very small nerves -> pass through foramina in the cribriform plate to the brain, where they form the olfactory nerve (CN1)
- Synapse with neurons in the olfactory bulb of the brain
- Regenerative neurons
function of bowman’s gland
Produces a constant flow of fluid surrounding olfactory cilia -> helps new odoriferous substances to access the cilia chemoreceptors of olfactory neurons
What is this?
horizontal cut of the nasal cavity
What is this?
Frontal/coronal section of the nasal cavity
How do nasal conchae promote the sense of smell?
They incrase turbulence wihtin teh nasal cavity, thus increasing contact between the inspired air and the mucosa
The nasal cavity is lined mostly with ___ epithelium, but also contains…
Respiratory epithelium, but also contains
- Swell bodies: thin-walled vessels just deep to the epithelium; warms air
- Olfactory epithelium on the most superior part
What is this?
Respiratory epithelium of the nasal cavity
- goblet cells
- cilia
- glands
What is this?
Olfacatory epithelium of nasal cavity
- lots of dark nuclei with no goblet cells
- bowman’s glands*
- axon bundles
(thsi cilia is nonmotile)