1.4 & 2.1 functional ultrastructure & cell bio Flashcards
T/F most epithelial cells have a basal membrane
false - All epithelial cells have a basement membrane
“adluminal” signifies
apical – toward the lumen
“abluminal” signifies
basal – away from the lumen
this cell surface specialization “beats,” and has a motile function
cilia
is connective tissue composed of cells or extracellular matrix?
both
why is “stereocilia” a misnomer
because they are not the same as cilia – they do not beat and have no motile function, only absorptive
this cell surface specialization functions to increase surface area for absorption but is too small to be resolved on LM
microvilli
what are goblet cells
glandular, simple columnar epithelial cells that secrete mucus
what prominent cell type can be found in a tracheal section but not an esophageal section?
cartilage
skeletal muscle fibers are “syncytia,” which means that they
are formed from several individual cells joining together during development
2 ways to tell smooth and skeletal muscle apart
- smooth muscle isn’t striated (less orderly actin/myosin filaments)
- smooth muscle has central nuclei vs skeletal muscle’s nuclei squished to the side of the cell
how can you tell glands and blood vessels apart?
glands are often ciliated and have thicker, more columnar epithelia vs blood vessels’ simple squamous epithelia
on LM, the basal lamina can only be seen as the _.
on EM, the basal lamina can be seen as the _, _ and _.
- basement membrane
- lamina lucida, lamina densa, lamina reticularis
lamina lucida
attached to basal cell
what does the “unit membrane” refer to
just an older term for “plasma membrane” of a cell
the two inner faces of a membrane lipid bilayer are called…
- the P-face (protoplasmic)
- the E-face (ectoplasmic
freeze fracture technique
freeze tissues and crack apart – cracks along hydrophobic domains of cell membranes (only parts that are not frozen) exposing hydrophobic areas of membranes
an important protein-sugar functional extension of the cell surface is called
glycocalyx
site of lipid/steroid production
smooth endoplasmic reticulum
site of protein packaging & addressing
golgi
on H&E, mitochondria stains…
eosinophilic
basal striations
folds in a membrane to increase surface area
endocytosis
uptake of substances from extracellular space
phagocytosis
uptake & digestion of extracellular substances
pinocytosis
cellular uptake of water, ions, and small substances
endosome
vesicle of endocytosis
vesicles designed to break down fatty acids through oxygenation
peroxisomes
vesicles for phagocytosis containing hydrolase enzymes
lysosome
difference between peroxisome and lysosome
- peroxisome breaks down fatty acid via oxygenation
- lysosome contains hydrolase enzymes
undigestible remnants of metabolic processes that accumulate in celles
residual bodies
what ion and protein can regulate exocytotic fusion with the cell membrane?
Ca++ and SARE proteins
3 elements of cytoskeleton
- thin filaments (actin)
- intermediate filaments
- microtubules
this cell cytoskeleton filament generally sits beneath the membrane and functions in motility, flxibility, and transmission of force across and between cells
thin filaments (actin)
this cell cytoskeleton filament forms a scaffolding and maintains shape of the cell
intermediate fliaments
this cell cytoskeleton filament forms a transport network in the cell
microtubules
intermediate filaments include these 3 proteins among others
desmins, keratins, vimentins
microtubules radiate out from the…
microtubule organizing center MTOC
a microtubule organizing center MTOC is organized around…
a pair of centrioles
MTOCs are referred to as ___ during cell division
centrosomes
what are the 4 cell junction types
- tight junctions
- desmosomes
- adhering junctions
- gap junctions
desmosome (latin name)
macula adherens (adhering spot - spot weld)
what kind of proteins comprise desmosomes
cadherin proteins on surface bound to cytoskeletal keratin intracellularly
junction that appears in EM as a roundish density centered over the membranes of two adjacent cells
desmosome
cadherins comprise what kind of cell connection
desmosome
when cadherin proteins bind a cell to connective tissue, the junction is called…
a hemidesmosome
latin name for adhering junctions
zonula adherens
macula adherens is the latin name for
desmosome (adhering spot, “spot weld”)
gap junction
electically conductive channel between neighboring cells fomed by transmembrane connexin proteins
which cell junction is composed of transmembrane connexin proteins?
gap junction
desmins, keratins, and vemintins are examples of proteins that make up what kind of cytoskeletal element?
intermediate filaments
what type of cytoskeletal filaments do desmosomes bind to intracellularly?
intermediate filaments (keratin)
are most proteins found on the E-face or the P-face of the cell membrane?
P-face – tells us that most anchors are intracellular
what kind of proteins comprise gap junctions?
connexins
connexins comprise what kind of cell junction?
gap junctions
what cytoskeletal filaments do adhering junctions connect to?
actin (thin filaments)
what cytoskeletal filaments do zonula adherens connect to?
actin (thin filaments)
latin name for tight junctions
zonula occludins
what kind of cell junction binds cells together for transmitting force?
zonula adherens (adhering junction)
what kind of cell junction binds cells together for transmitting electrochemical signals?
gap junctions
what kind of cytoskeletal filaments do gap junctions connect to?
none
what kind of transmembrane proteins compose tight junctions?
claudins and occludins
claudins and occludins make up what kind of cell junctions?
tight junctions
cadherins - what junction
connexins - what junction
claudins - what junction
occludins - what junction
cadherins - desmosomes and adhering junctions
connexins - gap junctions
claudins - tight junctions
occludins - tight junctions
adhering junctions are composed of…
cadherins connected to thin filaments
desmosomes are composed of
cadherins connected to intermediate filaments
adhering junctions and desmosomes are both made of cadherins but one binds to __ and the other binds to __
desmosomes = cadherins + intermediate filaments adherens = cadherins + actin filaments
what type of junction is usually located most apically?
tight junctions
a junctional complex consists of…
tight junctions, adhering junctions, and desmosomes
a hemidesmosome is…
a desmosome (cadherins + intermediate filaments) that connect cell to connective tissue
where is a junctional complex found… apically or basally?
toward the apical end of the cell
large amounts of what kind of organelle can give a cell a more eosinophilic stain?
mitochondria
In epithelia, an apical cell surface specialization that usually functions to move material along the surface is called
cilia
axoneme
the core of the cilium with, characteristic “9 doublets + 2 central” arrangement of microtubules
the core of the cilium, with characteristic “9 doublets + 2 central” arrangement of microtubules, is called
an axoneme
cilia insert into the cell body in structures called…
basal bodies, that consist of “9 triplets + 0” microtubules”
basal bodies, that consist of “9 triplets + 0” microtubules,” are the structures that insert this cell surface specialization into the cell body
cilia
what cell surface specialization has a characteristic “9 doublet + 2 central” microtubule core
cilia
the core of a microvillus consists of
longitudinally arranged f-actin, which is inserted into the actin of the cytoskeleton in an area called the terminal web
this cell surface specialization has an absorptive function and has a core of longitudinally arranged f-actin inserted into the cytoskeleton at the terminal web
microvilli
the microvilli border found in the kidney is called the…
brush border
the brush border is composed of This cell surface specialization in This organ
microvilli in the kidney
the microvilli border found in the intestines is called the…
striated border
the striated border is composed of This cell surface specialization in This organ
microvilli in the intestines
brush border vs striated boirder
brush - microvilli in the kindey
striated - microvilli in the intestine
a terminal web anchors what into the cell body
microvilli
a basal body anchors what into the cell body
cilia
nuclear pores allow the transport of…
RNA and small molecules
the nuclear membrane is continuous with this organelle
RER rough endoplasmic reticulum
in LM, the DNA complex is referred to as __
chromatin
largely unpacked and lightly appearing chromatin is called __
euchromatin
tightly packed and dense appearing chromatin is called __
heterochromatin
does a lightly staining nucleus probably contain euchromatin or heterochromatin?
euchromatin (unpacked)
does a darkly staining nucleus probably contain euchromatin or heterochromatin?
heterochromatin (packed)
the site of RNA production is called the __
nucleolus
the nucleolus is the site of…
RNA production
where do centromeres bind to chromosomes?
bind to center of chromosomes
where do a telomeres bind to chromosomes?
cap the ends of chromosomes
this structure binds to the center of chromosomes and organizes them during cell division
centromere
this structure caps the ends of chromosomes during cell division
telomere
this organelle becomes the centrosome and organizes chromosomes during cell division
MTOC
if n is chromosome number and x is chromosome copies, then the algebraic progression of chromosome number during mitosis is…
2n1x
2n2x
2n1x
if n is chromosome number and x is chromosome copies, then the algebraic progression of chromosome number during meiosis is…
2n1x
2n2x
2n1x
1n1x
controlled cell death, involving dissolution of chromosomal material, autodigestion, and lysing, is called…
apoptosis
apoptosis is designed to minimize…
exposure of the lysed cell to the immune system
weaker cell-cell adhesions in primitive embryonic epithelia may be made up of proteins including these 3:
cadherins, integrins, selectins (also found in adult vasculature, eg white blood cells)
cadherins, integrins, and selectins are examples of proteins that may make up weaker cell-cell adhesions found for example in these 2 instances:
- primitive embryonic epithelia
- adult vasculature (eg white blood cells)
the “e” in e-cadherin stands for __
epithelial
a cell freeing itself from adhesions to other cells and lamina, freenig itself to migrate, is undergoing __
de-lamination
T/F cells in connective tissue are highly connected and therefore their movement is restricted
false - connective tissue cells have very little attachement and are free to move
an example of “de-lamination” during gastrulation includes…
the migration of epiblast cells
the layer of extracellular glycolypids that function in part to make the membrane “slippery” is called
the glycocalyx
T/F the junctional complex encircles entire cell near apical end and is a good indicator of apical/basal polarity
true
this organelle supplies energy, has its own DNA, and pinches apart to divide
mitochondria
more mitochondria leads to a deeper ___ stain
eosinophilic
T/F the “primary cilium”, found in almost all cell types other than blood and bone marrow derived cells, has sensory and motor function
true
this cytoskeletal organelle has the appearance of perpendicular barrels on EM
MTOC
microtubule organizing center
this organelle produces diffusable molecules (eg steroid hormones)
SER smooth endoplasmic reticulum
the rough endoplasmic reticulum RER is for proteins to be packaged and addressed, otherwise proteins will be produced by..
free ribosomes in the cytoplasm
this organelle functions in protein storing and addressing
golgi
flagella consist of what type of filament and are related to what other kind of cell surface specialization?
- consist of microtubules
- related to cilium
a cell producing antibodies can be identified by these 2 appearances:
- basophilic cytoplasm (lots of RNA & ribosomes)
- clear area on edge of nucleus (golgi for packaging & sending)
this organelle contains acid hydrolase enzymes
lysosome
proteins regulating exocytosis include these 2:
- SNARES
- clathrin coats
in __, homologous chromosomes line up next to one another. in __, homologous chromosomes line up across from one another
- metaphase of mitosis - line up next
- metaphase I meiosis - line up across
this organelle produces ribosomes
nucleolus
paneth cells and mast cells are examples of…
secretory cells
- paneth cells may be found with goblet cells in glands of places like the intestine
- mast cells may be found in connective tissue and play a role in allergies, anaphlaxis, wound healing, and pathogen defense
merocrine secretion
vesicles fuse with membrane
apocrine secretion
lipid product is extravisated (mammary gland)
halocrine secretion
product accumulates in cell and is released by cell lysis (sebacous gland)
cytocrine secretion
product transfered directly from one cell to another (melanosome)
melanosome
cell functions in synthesis, transport, and storage of melanin
transcytosis
object taken up on one side of cell, travels across, and released on other side
vesicles fuse with membrane = __ secretion
merocrine
lipid product is extravisated (mammary gland) = ___ secretion
apocrine
product accumulates in cell and is released by cell lysis (sebacous gland) = ___ secretion
halocrine
product transfered directly from one cell to another (melanosome) = ___ secretion
cytrocrine
object taken up on one side of cell, travels across, and released on other side = ___
transcytosis
