Epithelia M2P Flashcards
What is the underylying ct that helps supply nutrients to epthilial
lamina propria
functions of epithelia?
PAST
Protectiction , Absorption, Secretion, Transpor
Where are simple squamous epithelium found?
example alveoli of lungs, blood vessels, CNS vasculature parietal, glomerular capsule of kidney
What are two specialized squamous cells? and what do they line
endothelial cells : line blood and lymphatic vessels
mesothelial : serous lining of viscera produce lubricating liquid
What do simple cuboidal epitheium lines?
line ducts (exocrine glands), tubules (kidney)
where are simple columnar epithelium cells found? what is so special about these cells?
found in stomach, intestines, gall bladder, lining large tubules
they are polarized
Where are Pseudostratified columnar epithelium found?
What do they have on the top vs Simple columnar?
these appear stratified but they are not. Most of these have cilia and therefore found primarily in the respiratory tract, vas deferens, epididymis
Simple Columnar have microvili ( gi tract intestines)
Pseudostratified have cilia
In stratified squamous epithelium how do cell division occurs and where are some of these found?
cell division occur in basal layer and cells differentiate as they pushed toward the apical surface.
found in the vagina
Types of stratified squamous epithelium ?
keratinized : remember top layer of cells lose their nuclei , help prevent water loss, found in epidermis of skin
nonkeratinized: found in oral cavity , esophagus, have nuclei
What are stratified cuboidal and stratified columnar epithelial found to do?
both provide structur for large ducts of exocrine glands.
Transitional epithelium?
stratitified epithelium sepcialized to stretch. Often binucleated! Look for them in the apical side
example in urinary system.
Esophageal stratified squamous epithelium mucous-secreting columnar cells in response to reflux of stomach acid
Can you think of some examples of metaplasia in epithelial cells?
respiratory epithelium to stratified squamous in response to inhalent irrirants
What is Microvilli made up and what is its purpose?
actin filaments and it increases surface area of the cell plasma membrane.
What is stereocilia and where it is found?
extremely long microvilli, found in the epididymis and vas deferens , absorptive function
What is the motile cilia structure?
core structure an axoneme 9+2 microtubules
What is nodal cilia involved in and can you think of a disease related?
involved in embryonic development , related to situs inversus
what is the function of basolateral domain?
lateral plasma membrane, cell to cell adhesion, communication
what is the function of basal plasma membrane
adhesion to basement membrane
a) Zona ocludens ?
b) Zona adherens?
a) tight junction
b) zona adherens (can be thought of like plastic rings that hold together a six pack) important for establishing cell polarity, diferentiation , proliferation
Maculae Adherens ?
what do they appear like?
Desmosomes: these are “spot welds” arranged along the basolateral membrane
these junctions appear as dense, semicircular plaques aligned on the cytoplasmic side o both cell membranes.
What dyes are good to visualize basement membranes?
basement membranes can be visualized using pas(magnenta) and silver
look at slide 28
What is the attachment site for epithelial cells and ct?
basal lamina
What do you find in primarty cilia?
imotile single projection no microtubule, function in sensation of chemical, osmotic, light, and mechanical stimuli
what is glandular epithelia?
epithelial cells specialized for secretion
what do globet cells secrete? and how do they appear
single secretory cells that secrete mucins (glycoproteins that form mucus) they stain clear
in gland structure what is parenchyma?and the stroma
the functional tissue of the gland .
stroma the supporting connective tisssue
Where are myoepithelial cells found?
some exocrine glands include myoepthelial cells these are epithelial cells containing contractile proteins that wrap around secretory cells to squeeze product into the duct.
for classification of exocrine glands what are classifications we use
Mechanism of secretion from cells
Composition of secretion
Morphology of the gland
Eccrine (merocrine)
cells polarized, these secrety by exocytosis
holocrine secretion
example
apical cells disintegrate and product enter the duct
ex: sebaceous gland
apocrine
cell membrane and cytoplasm suround the secretory product and pinch off. mamary gland undergoes boh eccrine and apocrine secretion
Composition of secretion for gland?
Serous : produce watery protein secretion, cytoplasm contains dark staining zymogen granules eosinophilic appear pink
Mucous : have glycoprotein product , poor staining in H&E
tubular usually secretes?
mucus, dark (in PAS)
acinar usually secretes?
sereous will look lighter on (PAS)
