Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
162 Cards in this Set
- Front
- Back
|
Normal platelet count?
|
150,000 - 450,000 cells/ul
|
|
|
Diameter of a RBC?
|
7.5 microns
|
|
|
How can you tell the nucleolus and heterochromatin apart with TEM?
|
nucleolus - blotchy
heterochromatin - homogeneous |
|
|
What does a dot matrix granule do?
Where is it found? |
Calcium sump in mitochondria
|
|
|
G1 phase
|
biosynthetic activity, cell growth
|
|
|
S phase
|
DNA replication
|
|
|
G2 phase
|
final growth to prepare for mitosis
|
|
|
When does most nondysjunction occur?
|
1st meiotic division of women
|
|
|
RNA polymerase I
|
rRNA
|
|
|
RNA polymerase II
|
mRNA and miRNA
|
|
|
RNA polymerase III
|
tRNA and other small noncoding RNA
|
|
|
Barr body
|
inactivated X chromosome in females which forms a visible block of heterochromatin
|
|
|
Effect of histone acetylation (via HAT)
|
losens contact with DNA, exposing DNA, making it more accessible (Acetylation = Accessible)
|
|
|
Nissl substance
|
rER and polyribosomes in neurons
|
|
|
Where does growth occur in actin
|
fast growth on + end, slow growth on - end. It grows toward the center of the cell until capping proteins stop them
|
|
|
desmosome
|
aka macula adherens, dark staining areas, link epithelial cells together (spot weld)
interact with intermediate filaments on internal surface of cell membrane |
|
|
hemidesmosome
|
bind attachment plaque directly to the basement membrane
|
|
|
microtubule function
|
cell motility, cell division, intracellular movement
(major component of cilia and flagella) |
|
|
where are microtubules embedded?
|
minus end embedded in centrosome, near nucleus
|
|
|
dynamic instability of microtubules
|
grow at + end and lost at - end
disrupted by high calcium levels or drugs (e.g. taxol) |
|
|
Kartagenr's Syndrome
|
effects: male infertility, respiratory infections, sometimes situs inversus.
cilia and flagella lack dynein side arms which attach to microtubules to make them motile |
|
|
dynein
|
motor protein in cells, transports cargo toward minus-end (toward center of cell)
|
|
|
microvilli
|
inner core of actin
increase surface area for absorption (seen in intestines) nonmotile |
|
|
stereocilia
|
longest cell surface modification
nonmotile in epididymis and sensory cells of inner ear only |
|
|
cilia
|
motile
basal body found in respiratory and female reproductive tracts don't stain as homogenously as bruch border inner core of microtubules (9+2 pattern) |
|
|
basolateral interdigitations
|
function to increase surface area
full of Na/K pumps situated along their basal aspect of cells in kidneys and salivary glands lots of mitochondria |
|
|
major components of extracellular matrix
|
ground substance and fibers
|
|
|
components of ground substance
|
glycosaminoglycans (GAGs) and proteoglycans
|
|
|
describe GAGs
|
large unbranched polysaccharide chains, mostly sulfated
sulfates attract sodium, which brings in water (keep it hydrated) |
|
|
describe proteoglycans
|
arrangement of GAGs surrounding a core protein, part of ground substance, like bottle brush
responsible for gel-like state of matrix, restrict movement of bacteria and cancer cells |
|
|
myxedema
|
caused by hyper- and hypothyroidism
over deposition of GAGs and proteoglycans under eyes and over nose |
|
|
thrombocytopenia
|
low platelet count, often caused by chemotherapy or cell destruction in the spleen
|
|
|
purpura
|
pools of perforated cells (like a bruise)
|
|
|
petechia
|
needlepoint hemorrhages
|
|
|
what is an inclusion? give examples
|
nonmembrane bound components of cell
(glycogen, lipids, pigment) |
|
|
where is glycogen stored?
|
muscle (alpha glycogen)
liver (beta rosettes) |
|
|
rough ER
|
protein synthesis (especially to EXPORT) and glycosylation of nascent proteins (addition of sugar group)
|
|
|
polysome (polyribosome)
|
protein synthesis (for use WITHIN THE CELL)
|
|
|
smooth ER
|
secrete hormones
prominent in liver, striated muscle, adrenal cortex Note: doesn't stain with H&E |
|
|
Golgi apparatus
|
packages proteins and enzymes
cis-face - facing rER, gets small vessicles trans-face - larger vacuoles come from here Note: doesn't stain with H&E |
|
|
Lysosomes
|
contain hydrolytic enzymes (digest)
have H+ pumps to acidify lumen when digestion of fused materials begins - secondary lysosome |
|
|
lipofuscin/lipochrome
|
gold/brown staining partially digested material from lysosomes
prominent in cells that secrete hormones |
|
|
secretory granule
|
fuse with plasma membrane to release contents (exocytosis)
e.g. eosinophils display football shaped granules with line down middle |
|
|
mast cell
|
connective tissue cells
secrete many substances, many granules in cell |
|
|
xenobiotic agent
|
foreign substance
|
|
|
template-dependent RNA polymerase
|
makes RNA using a single-stranded DNA template
|
|
|
promotor
|
DNA sequence which signals where to initiate transcription
(position dependent) |
|
|
enhancer
|
DNA sequence where transcription factors bind
(position/orientation INdependent) |
|
|
transcription factor
|
DNA binding protein that can up-regulate transcription enhancing RNA polymerase ability to bind to promotor
bind to enhancers |
|
|
silencer
|
DNA sequence which bind proteins that block transcription
(position/orientation INdependent) |
|
|
euchromatin
|
decondensed
means transcription is occuring |
|
|
heterochromatin
|
condensed
low transcription |
|
|
lipophilic hormone's effect
|
get bound by transcription factors which then encode hormone-induced proteins
|
|
|
tamoxifen
|
competes with estrogen for estrogen receptor (antagonist)
|
|
|
Decitabine
|
ex. of DNA methylation inhibitor
|
|
|
FK228
|
histone deacetylase inhibitor, works with demethylating agent to activate genes (hopefully to silence a tumor)
|
|
|
fibroblast
|
long cells, make fibers and ground substance, lots of rER (producing matrix), well-developed Golgi, surrounded by collagen fibers
|
|
|
what are microfilaments?
|
actin and myosin
|
|
|
what are the 3 major components of cytoskeleton
|
microfilaments
intermediate filaments microtubules |
|
|
intermediate filament characteristics
|
provide structural support
only fibrous cytoskeletal component intertwined monomers |
|
|
hemidesmosome
|
attatch a cell to extracellular matrix (basement membrane)
|
|
|
what does actin do in microvilli?
|
contract to reduce surface area, less absorption (for toxins)
|
|
|
constitutive (constant) secretory pathway
|
found in ALL CELLS
lipids and proteins are packaged into transport vesicles in the trans golgi network (TNG) for immediate delivery to cell surface |
|
|
regulated secretory pathway
|
found in ONLY SOME CELLS
specific proteins are sorted into secretory storage vesicles/granules granules only fuse with plasma membrane when cell receives external stimulus (e.g. neurotransmitter) that causes increase in intracellular calcium |
|
|
how are soluble lysosomal enzymes sorted?
|
they are tagged with a phosphate in the cis Golgi. they have a signal patch which leads to attachment of a mannose-6 phosphate which is recognized by the trans golgi network (via MPRs). they are collected into vessicles and fused with late endosomes (MPR's recycled) phosphate is cleaved from enzyme and delivered to the lysosome
|
|
|
autophagy
|
enclosure of an obsolete membrane within a cell to be degraded in a lysosome
|
|
|
phagocytosis
|
internalization of bacteria and foreign material
|
|
|
endocytosis
|
ingestion of plasma membrane and extracellular material
|
|
|
endocytic pathway
|
endocytic vessicle fuses with early endosome (acidic)
some proteins are returned to cell surface, while the rest moves inward and fuses with acidic late endosomes then contents go to lysosome http://www.youtube.com/watch?v=PifagmJRLZ0 |
|
|
pinocytosis
|
random sample of membrane and extracellular fluid is pinched off
|
|
|
clathrin-dependent endocytosis
|
receptors bind nutrients
tails of receptors bind adaptor proteins adaptor proteins are bound by clathrin clathrin causes bending and pinching off |
|
|
receptor-mediated endocytosis advantages
|
efficent, selective uptake of nutrients
receptors are recycled between early endosome and cell surface |
|
|
constitutive endocytosis
|
independent of ligand binding
continuously cycle |
|
|
what does hormone-binding do?
|
stimulates the endocytosis not only of the hormone, but the hormone receptors (so you don't continue the cycle since the receptor is sent to lysosome too)
|
|
|
stratum basale
|
basal layer of skin cells
|
|
|
stratum spinosum
|
layers above stratum basale
|
|
|
fimbrin/fascia
|
actin binding proteins
|
|
|
transcytosis
|
in polarized cells
transporting soluble molecules from one side of cell to the other (endocytosis doesn't go to lysosome) ex. transfer of mother's serum antibodies across epithelia to mammary glands to her breast milk baby does oposite to put antibodies on cell surface |
|
|
how do polarized cells sort newly synthesized plasma membrane proteins?
|
polarized cells have 2 distinct plasma membrane domains
sorting signals say which way to go |
|
|
what is capacitation?
|
physiological process that results in sperm hyperactivity
necessary for fertilization |
|
|
phases of fertilization
|
1. sperm penetrates corona radiata
2. sperm penetrates zona pellucida 3. fusion of sperm and oocyte |
|
|
cortical reaction
|
after fusion with sperm, this releases cortical granules, hardens zona (zona reaction) to become impermeable to sperm
|
|
|
what stage of meiosis is the oocyte arrested in before sperm fusion?
|
metaphase of the second meiotic division
|
|
|
blastomeres
|
cells undergoing division after fertilization
|
|
|
what does the trophoblast develop into?
|
fetal part of placenta
|
|
|
predecidualization process
|
uterus gets ready for implantation (before deciduization or sluffing off, like deciduous trees)
|
|
|
trophoblast differentiation
|
cytotrophoblast - inner layer
syncytiotrophoblast - outer layer that makes enzymes for deep penetration |
|
|
human chorionic gonadotropin (hCG)
|
made by syncytiotrophoblasts
maintain progesterone levels high for pregnancy used for pregnancy test |
|
|
what are the fibrous components of extracellular matrix?
|
collagen fibers, reticular fibers, and elastic fibers
|
|
|
two types of collagen fibers?
|
fibrillar (1-3) and nonfibrillar (4,7)
|
|
|
describe type I collagen
|
stains eosinophilic
strongest fibers (so it's found in fibrocartilage, skin, bone, ligaments, tendons) |
|
|
where is type II collagen found?
|
it's smaller, found in hyaline and elastic cartilage
|
|
|
what is type III collagen?
|
it's the same as reticular fibers
|
|
|
where is nonfibrillar collagen found?
|
in basement membrane (type IV and VII)
|
|
|
where is collagen synthesized?
|
in rER, goes to golgi, goes to extracellular environment
|
|
|
describe reticular fibers
|
type III collagen
most delicate found just below basement membrane |
|
|
describe elastic fibers
|
give stretch and flexibility
have inner core protein |
|
|
what are MMPs?
|
matrix metalloproteinases
secreted by certain cells (important in embryogenesis, growth, and cancer) to move through different tissues |
|
|
what is the basement membrane?
|
made of basal lamina and lamina reticularis
prominent in the kidney used for cellular adhesion |
|
|
basal lamina components
|
lamina lucida + lamina densa
|
|
|
lamina lucida
|
laminin (which binds to transmembrane proteins) and entactin
|
|
|
lamina densa
|
full of type IV collagen, perlacan, and fibronectin
functions in adhesion and filtration |
|
|
lamina reticularis
|
full of type I and III collagen
"bolts down" basal lamina |
|
|
goodpasture's syndrome
|
body produces autoantibodies against portions of type IV collagen of lamina densa in GBM
too much protein gets through protein rich and bloody urine |
|
|
lacunae
|
small space containing osteocyte or chondrocyte
|
|
|
stroma
|
connective tissue
|
|
|
lamellae
|
sheets of elastic material (porous)
|
|
|
hematuria
|
red blood cells in urine
|
|
|
proteinuria
|
>300mg/24hrs protein in urine
|
|
|
podocalyxin
|
protein in podocytes
|
|
|
septa
|
connective tissue, goes through organs for additional support
|
|
|
endocrine denotes the action of a first messenger when signaling cells release first message into...
|
the systemic circulation
|
|
|
paracrine denotes the action of a first messenger when signaling cells release first message into...
|
the extracellular space (acts locally on neighboring cells)
NOTE: this can be autocrine |
|
|
why might different cells react differently to the same signal?
|
-they have different receptor proteins
-they have different intracellular signaling molecules |
|
|
what is the Kd?
|
concentration of ligand that results in 50% of the receptors bound
|
|
|
what is the EC50?
|
the concentration of a ligand that elicits 50% of the maximal response
(potency) |
|
|
what is the efficacy of ligand?
|
the maximal response (Emax) that a ligand can elicit
|
|
|
what is the importance of cascades in signaling?
|
they transfer signal
they can amplify signal they can distribute signal each step can be regulated |
|
|
pattern for G-protein coupled receptors
|
extracellular N-terminal
intracellular C-terminal seven alpha helicies that span membrane |
|
|
Gαs
|
stimulates adenylate cyclase
|
|
|
Gαi1,2,or 3
|
inhibits adenylate cyclase and stimulates MAPKinases
|
|
|
Gαz
|
K+ channel closure
|
|
|
Gαq/11
|
stimulates phosphatidylinositol phospholiase C (β FORM!)
|
|
|
how is the GTP cleaved to GDP when bound to a Gα subunit?
|
the subunit itself is a GTP phosphodiesterase and cleaves the terminal phosphate
|
|
|
what is adenylate cyclase?
|
responsible for generation of second messenger molecule cyclic AMP
Note: This is localized on the PLASMA MEMBRANE |
|
|
what is phosphatidylinositol phospholipase C β (PIPLCβ)?
|
hydrolyzes PIP2 to generate second messengers inositol triphosphate (IP3) and diacylglycerol (DAG)
|
|
|
What does cyclic AMP do?
|
activates cAMP-dependent protein kinase (PKA) (produce glucose signal)
|
|
|
what does diacylglycerol (DAG) do?
|
activates protein kinase C (PKC)
diffuse in plasma membrane giving local signal in membrane (basic signal is rest and digest) |
|
|
what does inositol triphosphate (IP3) do?
|
goes into ER, binds to IP3 gated channels that release Ca2+ into cytosol
|
|
|
how is calcium regulated in cells
|
levels kept low in cytosol by ejecting calcium from cell and pumping it into the lumen of the ER
|
|
|
what is calmodulin?
|
calcium-sensing protein, when [calcium] increases, it binds to calmodulin, changes its conformation, allows binding to effectors (e.g. kinases)
|
|
|
what does Gβγ do?
|
activates GTP binding protein Ras (only those coming from Gi1,2,3 or Go)
|
|
|
what does Ras do?
|
oncogene (proliferation) via MAPKinase and PI3 pathways
|
|
|
MAPKinase cascade
|
Raf→Mek→ERK
only substrate for Raf is Mek, and only substrate for ERK is Mek |
|
|
types of heterochromatin
|
marginal (periphery of nucleus), karyosomes, nucleolar
|
|
|
examples of multinucleated cells
|
osteoclasts, skeletal muscle, megakaryocyte
|
|
|
what does megakaryocyte do?
|
produce platelets
|
|
|
osteoclast/osteoblast
|
clast - bone resorbtion (break down)
blast - build up bone |
|
|
two cells with no nucleus
|
RBC, platelet
|
|
|
what does nucleolus do?
|
synthesize ribosomal subunits (rRNA)
|
|
|
adipocyte
|
fat cell, unilocular, nucleus off to side
|
|
|
multilocular vs. unilocular fat
|
multilocular - uncommon in adults, numerous lipid droplets, thermogenic in newborns, more mitochondira (brown fat)
unilocular - very common, white fat |
|
|
lymphocyte (types, characteristics)
|
B or T cells, large nucleus compared to cell size, provide resistance to pathogens in respiratory, gastrointestinal, reproductive tracts
|
|
|
plasma cells
|
derived from B cells, produce antibodies (humoral immunity i.e. body fluids) lots of rER
|
|
|
when do neutrophils function?
|
during inflamation
|
|
|
describe neutrophils
|
WBC
can phagocytose bacteria multilobulated nucleus lots of granules |
|
|
eosinophils
|
white blood cell, bilobed nucleus, football granules
|
|
|
macrophages
|
lots of lysosomes, ingest bacteria, debris, etc
|
|
|
types of embryonic connective tissue
|
mesenchyme
mucous connective tissue (only in umbilical cord) |
|
|
types of adult connective tissue
|
loose (areolar) (see 15-5)
dense irregular (see 15-6) dense regular (see 15-6) |
|
|
effects of lysosomal storage diseases?
|
missing enzyme so things aren't broken down and are stored instead
|
|
|
totipotent vs. pluripotent
|
totipotent - zygote, can develope into ANY type of cell
pluripotent - blasatocyst, can give rise to all cells except for extra embryonic tissue |
|
|
describe enzyme linked receptors
|
enzyme is part of receptor
|
|
|
describe tyrosine kinase receptor
|
single membrane spanning receptor
forms DIMERS upon ligand binding, then TRANS phosphorylation, which super-activates tyrosine kinase, then CIS phosphorylation (phosphorylates itself), ***activates PIPLCγ activates Ras causes cell proliferation |
|
|
what happens if you have more mutant tyrosine kinase receptors than normal ones?
|
you get no activity, because no trans phosphorylation occurs to activate
|
|
|
describe JAK-STAT receptors
|
are cytokine receptor
separate polypeptide chains activate tyrosine kinase activity transmit info directly to target gene promotors in nucleus (no second messengers) upon binding it dimerizes (can be trimers also), get trans phosphorylation, then cis phosphorylation, then stat comes in and gets phosphorylated and it dimerizes and goes into nucleus (only after dimerizes) |
|
|
describe serine/threonine pathway
|
TGF-β (growth factor), phosphorylates serine and threonine
ligand binds, oligomerization, trans P, causes smads to attach, smads are phosphorylated, dimerize, switch out for smad4, dimer (one phosphorylated, one not (4)) goes into nucleus |
|
|
describe toll receptors
|
immune response
LPS binds to receptor, activates IkK, phosphorylates IkB, IkB releases from NFkB and NFkB goes into nucleus |
|
|
how does cell become desensitized to a signal?
|
inactivation of receptor by phosphorylation (can be homozygous or heterozygous)
|
|
|
what is signal downregulation?
|
receptor removed from plasma membrane and degraded or recycled
|
|
|
what does PIPLCγ do?
|
PIP2 cleaved, IP3 and DAG
|
|
|
beta arrestin
|
desensitization/downregulation
|
