Respiratory Epithelium Flashcards
conducting epithelium
-where is it found
pseuodostratified, ciliated, columnar, with gobs
- nasal cavity
- larynx, trachea
- bronchi
- intrapulmonary bronchi
- however, transitions to non-ciliated cuboidal epithelium in deeper passageways
- NO gas exchange occurs here!!
- enteroendocrine cells, kulchitsky cells are present here
what cell types do you find in gas exchange epithelium?
type 1 and 2 alveolar (pneumocytes) cells
olfacotry epithelium is composed of
- supporting cells (these cells reach the surface and have non-motile cilia
- olfactory cells (bipolar neurons): these have dendrites which reach up to the surface and are what transmit the smell signal, axons extend into the lamina propria and are surroudned by schwann cells
- basal cells (stem cells)
- bowmans glands under epithelium
kulchitsky cells
- enteroendocrine cells foundin the resp tract
- small granule cells
- release catecholamine, serotonin, calcitonin, etc
respiratory problems in CF
- defective chloride channel makes the mucous very concentrated
- due to the lack of eflux of Cl, a lot of Na comes into the cell in order to maintain the gradient and water rushes into the cells along with the sodium, leaving the mucous remining in the lumen very thick (viscous)
trachea is composed of (from lumen to outer layer)
- respiratory eptihelium
- lamina propria
- longitudinal elastic fibers
- submucosal mixed seromucous glands (lots of glands)
- hyaline cartilage
- adventitia
- there is also a muscle on one side called the trachealis muscle which can stretch when food is going down the esophagus or narrow when coughing
- THERE IS NO MUSCULARIS MUCOSAE
bronchiole
- no mucosal glands
- no cartilage
- few goblet cells
- many club (clara) cells
- mostly simple cuboidal cells
club cells
- non ciliated
- produce surfractant components
- repair (stem cells)
- protect against inflammation and oxidative stress
- this is not the main surfactant that is going to keep the lung open
respiratory bronchiole
- bronchiole with alveoli (at least one)
- capable of gas exchange in alveoli
surfactant
- surface active agent
- dipalmitoylphosphatidylcholine
- proteins
- reduces surface tension in order to make lungs more compliant and prevent atelectasis (collapse)
respiratory distress syndrome
- surfactant is not produced in large volumes until about 6 months of developmetn
- may occur with premeys that are incapable or inefficient at producing surfactant
- administered corticosteroid to increase production
cells of the alveoli
- type 1 and 2 pneumocytes
- macrophage
type 1 pneumocyte
- thin nuclei,
- creates 90% of the surface area for gas exchange
- has a very thin cytoplasm that surround the endothelial cells of capalaries that are carrying blood to the lungs
- not capable of cell division, requires proliferation of type 2
- very squamous
type 2 pneumocyte
- contain lamellar bodies that are represented as clear areas within the cell. lipid rich sotred surfactant
- round nuclei
- produce surfactant
- progenitors for type 1 pneumocytes
macrophage
-known as a dust cell in the lung
pulmonary artery and vein
- pulmonary artery comes from the left ventricle andis full of deoxygenated blood which is carried to the lungs
- the pulmonary veins then bring this
- much larger than the brionchial arteries and veins
- folows the bronchial tree very well, shares an adventitia
bronchial arteries and veins
- arteries bring oxygenated blood to the cells of the lungs in order for them to survive
- located immediately adjacent to the bronchiole
- no bearing on gas exchange
trachea extends from and goes to
larynx and goes to the bifurcation
intrapulmonary bronchiole
- lumen has a lot of fold with muscularous mucosae
- in the adventitia, the hyaline cartilage is in plates, this is diagnostic
- onc the plates disappear then it is called abronchiole
asthma
-increase thickness of the muscular layer
alveolar duct
- the entire wall is capableof gas exchange
- ends in an alveolar sac
pulmonary alveoli
-these need surfactant so that the sides dont stick together
alveolar wall is filled with
capillaries
