Epithelia Specialization Flashcards
1
Q
apical surface specialization
A
- microvilli
- glycocalyx
- cilia
- stereocilia
2
Q
lateral surface specialization
A
- zonula occludens
- zonula adherens
- macula adherins (desmosomes)
- gap junctions
3
Q
basal surface
A
- hemidesmosomes
- basal lamina
- basal invagination
- basal evagination
4
Q
microvilli
- where
- size
- resolvability
- shape
- function
A
- apical surface
- uniform in length
- not resolvable on LM
- striated or brush border
- absorptive/secretory function
5
Q
glycocalyx
- what
- function
- composition
A
- cell coat
- adsorbs pancreatic enzymes
- high in glycoproteins
6
Q
cilia
- function
- appearance
- resolvability
- length in comparison to MV
- composition
- core structure
A
- motile/coordinated beating
- uneven appearance
- resolvable on LM
- much longer than microvilli
- core of microtubules
- axoneme
7
Q
primary cilia dyskinesia
- aka
- mechanism (what it affects)
- complications
A
- immotile cilia syndrome
- heterogenous, usually affecting dyneins
- complications in the lung, ear, and fertility
8
Q
Kartageners syndrome
- description
- associated complications (not having to do with epithelial components)
A
- broader involvement of the ciliary defects
- includes sinus inversus, bronchiectasis, and chronic sinusitis
9
Q
stereocilia
- shape
- length
- connections
- composition
- function
A
- elongated, non-motile microvilli
- frequently as long as the cell itself (cilia are much shorter)
- often connections between adjacent stereocilia exist (clumping)
- core of actin filaments
- functions: absorption, mechanosensory
10
Q
terminal bar
A
appears as a spot on the LM, this is where the lateral specializations reside
11
Q
zonula occludens
- aka
- regulate
- create
- interations with transmembrane proteins, cytoskeletal proteins, and intracellular peripheral membrane protein complexes
A
- tight junctions
- regulate apical border seal
- create apical/basolateral domains
- provide a selectively permeable barrier
- tansmembrane: occludin and claudin
- cytoskeletal proteins: actin
- intracellular peripheral: ZO-1 and cingulin
12
Q
leaky zonulae occlude can lead to
A
celiac disease (gluten intolerance)
13
Q
zonulin
- what protein does it target?
- when is it released?
A
- release loosens tight junctions by dissociating ZO-1
- release is stimulated by gluten and bacterial overgrowth in gut
14
Q
cholera toxin and zonulin
A
-releases a zonula occludens toxin which is equivalent to zonulin and leads to fluid release into the gut causing diarrhea
15
Q
zonula adherens
- classification/dependency
- associated with what cytoskeleton component
- function
- tightness
A
- Ca dependent intracellular junctions
- has E-cadherin homotypic intercellular linkages
- continuous with actin cytoskeleton
- resist mechanical stress
- transduce signals from adjacent cells and ECM (responds to stretching)
- not nearly as tight as the tight junctions
