Test 1 Flashcards
when can frozen tissue sections be used?
when an urgent tissue diagnosis is needed, unexpected nodule during surgery, presence of matastasis beyond a proposed resection field
can you see fine details better in a routine section of tissue or a frozen section?
routine section, but the frozen section can be completed quickly
direct method of immunocytochemistry
less sensitive technique; tag an antibody with a marker; this antibody tags the antigen and you view the sample under a fluorescent microscope
indirect method of immunocytochemistry
more sensitive technique; apply antibody to antigen; the first antibody is then tagged with another antibody; this amplifies the signal by attaching more antibodies to the antigen; view under fluorescent microscope
what does anticytokeratin immunoperoxidase technique reveal?
tumor originates from epithelial cell and possesses cytokeratin
what antigen marker is specific to lymphatic vessels?
D2-40
in situ hybridization
try to find a specific genetic sequence to a given sample; the complimentary sequence is tagged with fluorescent marker to tag the sequence
if you are positive for TTF1, what does this suggest
cancer of the lungs, specifically adenocarcinoma
Creutzfeldt-Jakob disease
caused by prions; ataxia, paralysis, dementia, and eventually death
antagonist
a signal that blocks the normal extracellular signal
agonist
mimic the effect of a signal
up and down regulation of receptors
receptors are not static; they can be upregulated if the signal is present in decreased amounts; they ca be down regulated in response to increased signals
estrogen receptors
estrogen receptors are found in the nucleus
macropinocytosis
an active process that internalizes substances via microfilaments from outside of the cell; the process by which salmonella typhimurium infects the body; also utilized by thyroid hormones and immune cells
non-clathrin/noncaveolar
a transport mechanism that uses a vesicle to move substances in the cell; the vesicle has neither a clathrin or caveolae coat; the method by which cholera ans shiga toxin enter the cell
explain clathrin-mediated receptor endocytosis
- cargo protein interacts with cargo receptor 2. formation of coated pit around receptors 3. formation of coated vesicle (cathrin) in a GTP dependent reaction that uses dynamin 4. vesicle is internalized 5. coat breaks down 6. uncoated vesicle ready to use, including cargo
how does LDL move into the cell?
clathrin-mediated receptor endocytosis; the receptor can be mutated so that the coated vesicle cannot form, ultimately leading to atherosclerosis
phagocytosis
cell internalizes large substances; typically is mediated by receptors; bacteria attaches to receptors and is internalized into a phagosome; when in the cell, lysosomes can break down the bacterium; this can also occur with nonbiologic material
what are 3 secretion processes?
exocytosis, porocytosis, exosomes and exosome-like vesicles
what are the 2 pathways of exocytosis?
regulated pathway and constitutive pathway
explain the constitutive pathway
the cell is constantly producing vesicles for secretion only, never for storage
explain the regulated pathway
FINISH THIS
explain porocytosis
method that releases NT into synapse FINISH THIS
explain exosomes
what is the general rule for proteins made by rER?
they are secreted, put into the plasma membrane, or ____
what is the general rule about proteins made by free ribosomes
they generally stay within the cell
what are functions of the rER
- synthesis of proteins for secretion, insertion into membranes, and lysosomal proteins 2. synthesis of sER enzymes 3. protein modification
what are the unfolded protein responses (UPRs)
- increased synthesis of chaperones to repair the proteins 2. decreased translation of proteins 3. activation of the ubiquitin-proteasome pathway 4. activation of caspases to trigger apoptosis
what are the functions of the sER?
- steroid synthesis 2. cholesterol homeostasis 3. synthesis of phospholipids 4. glycogen metabolism 5. detox of drugs 6. storage, release, and uptake of calcium ions in striated muscle
Von Gierke’s disease
a glycogen storage disorder; you have a mutation in teh G6P transporter OR in glucose 6-phosphatase leading to glycogen storage problems
what happens to the volume of sER in response to phenobarbital?
if you chronically administer phenobarbital the volume of the sER increases as to break down the phenobarbital
where are phospholipids synthesized?
sER and rER
what does the the phospholipid exchange molecule do?
shuttles membrane phospholipids from the ER to other organelles
atlastin
atlastin, a GTPase, is a protein involved in constructing and shaping the ER; the abundance leads to ER membrae fusion and normal Golgi is absent, deficiency leads to —–
where do proteasomes exist?
cytoplasm and nucleus
what do most proteasomes depend on?
ubiquitin
how do prion proteins affect proteasomes?
it is thought that they inhibit the proteasome activity; defective ubiquitination of proteins is implicated in Parkinson disease
how does bortezomib treat cancer?
effective against multiple myeloma by inhibiting proapoptotic molecules
what are the functions of the golgi?
proteins are sorted based on chemical zip codes such as the linear sequence of amino acids or attached carbohydrate moieties, proteins are modified, and proteins are packaged into vesicles
what is dysferlin used for?
repairing the plasma membrane
if dysferlin is messed up, what happens?
mutations of the dysferlin gene are found in 3 types of MD——
explain insulin secretion via golgi
finish
what is the fate of a late endosome
it becomes a lysosome or fuses with an existing lysosome
what are 2 possible fates of endocytosed receptors and ligands
- receptor is recycled and ligand is degraded 2. receptor and ligand are recycled
true or false: defects in M6P synthesis may lead to disease?
true; results in a lysosomal storage disease
describe the lysosome
the lysosome is the most acidic compartment in the cell; the acidity allows the enzymes within the lysosome to work in the most efficient way possible; it has the ability to degrade nucleotides, lipids, carbs, proteins
explain autophagic pathway(s)
an organelle is delivered to a lysosome surrounded by endoplasmic reticulum; within the lysosome the organelle is broken down; another way is microautophagy and chaperone mediated autophagy
contrast primary and secondary lysosomes
primary lysosomes are homogeneous and are not breaking down anything; secondary lysosomes are heterogeneous and have undergone a phagocytotic process
Pompe disease
glycogen storage disorder; results from inability of lysosome to break down due to an effected enzyme in the lysosome. this leads to a buildup of glycogen
tay-sachs disease
sphingolipidosis - hexoaminidase A deficiency ;lysosomes fill up with sphingolipids
COPII
directs anterograde flow from the ER to the Golgi
COPI
directs retrograde flow back to where signal came from
Clatherin
directs material into endosomes?
what is the function of coating proteins?
to direct molecules between one compartment to another
what is the function of SNARE proteins
they are incorporated into the vesicle or docked on a receiving compartment; v-SNAREs are in vesicles and will recognize tSNAREs at a target compartment
what is the role of botulinum toxin in the neurologic tissue
what does the amount of crista tell you?
it tells you the state of the cell and cell type; as need for ATP increases, so does the amount of cristae in the cell
how do CO and cyanide poisoning work?
they disrupt the ETC
what is a palisade of mitochondria
what are tubular cristae associated with?
steroid hormone synthesis; cells that produce steroids have mitochondria that are made up of tubular cristae
myoclonic epilepsy
frequent twitching of muscles
functions of peroxisomes
beta ox of FFA, plasmalogen synthesis, regulation of peroxide, killing pathogens, oxidizing EtOH
Zellweger syndrome
impaired import of enzymes into peroxisomes
name some cytoskeletal eleents
microtubules, filaments (actin, intermediate filaments, and myosin)
what is the action of kinesin?
transports molecules down a microtubule from one end of a cell to another
what kind of dye labels mitochondria?
mitotracker red
what does DAPI do?
stains the nuclear DNA blue
actin microfilaments
have a positive an negative end; tend to grow/assemble at positive end and disassemble at the negative end
what do cytochalasins do?
they inhibit actin polymerization
where is the intermediate filament cytokeratin associated with
epithelial cells
where is the intermediate filament desmin associated with
muscle (smooth and striated)
where is the intermediate filament glial fibrillary acidic protein associated with
astrocytic glial cells
where is the intermediate filament neurofilament associated with
neurons
where is the intermediate filament nuclear lamin associated with
nucleus of cells
epidermolysis bullosa simplex
mutations in the keratin 5 or 14 gene prevent keratin from assembling into strong networks; epidermis of skin becomes fragile and easily damaged
progeria
caused by defects in the nuclear lamina
role of lamins during mitosis
FINISH THIS
contrast euchromatin and heterochromatin
heterochromatin is tightly coiled; euchromatin is loosely arranged; you can identify how active the cell is in regards to transcription by looking at the chromatin: lots of euchromatin means lots of transcription, folks!
would you see a nucleolus in a cell with heterochromatin?
no!
thyroid cancer nucleus
“orphan annie” eye nuclei - the nucleus is white
contrast nucleolus and nucleus
the nucleolus is within the nucleus; appears as a dark circle within the organelle
nucleolus features
nucleolar organizer DNA, pars fibrosa, pars granulosa, nucleolus-associated chromatin
nucleostemi
p53 binding protein found in undifferentiated cells; decreases as cells become differentiated; presence in cancer cells may play a role in unchecked proliferation
contrast chromatid and chromosome
when a chromosome is duplicated it is attached to its copy and each copy is now known as a chromatid
what is the action of colchicine, vincristine, and vinblastine?
inhibit polymerization of microtubules
what is the action of taxol?
promotes polymerization and inhibits depolymerization of microtubules
contrast telomerase in germ and somatic chromosomes
it is present in germ cells but not in somatic
contrast necrosis and apoptosis
with apoptosis, the cell is eliminated “under the radar”; with necrosis there is an inflammatory response
what might an aggressive tumor do to make it less susceptible to apoptosis?
increase anti-apoptotic factors
why do women get osteoporosis more often?
estrogen has an anti-apoptotic effect on osteoblasts thus promoting their longevity
functional attributes of ECM
structure, defense and protection, nutrition, diffusion of gases molecules and ions, cell growth and survival, cell migration, lubrication
what makes up the ECM
ground substance (glycosaminoglycans, proteoglycans, water, adhesive glycoproteins) and fibers (collagen, reticular collagen, elastic)
what is the hallmark of tissue repair?
granulation tissue
how is contact with the extracellular matrix related to the cell cycle?
cells making contact with the ECM are more likely to divide and proliferate; more contact = more likely to enter S phase
what happens to the hydrated state of tissue when there is excessive accumulation of glycosaminoglycans?
the hydration state increases
proteoglycan
a more complex structure of glycosaminoglycan; a glycosaminoglycan is attached to a linker protein which attaches to hyaluronan
what is perlecan?
perlecan is needed for correct development of the skeletan
what happens when antibodies block fibronectin function?
branching morphogenesis is disrupted (mouse salivary gland was the example in class)
what AA is measured to calculate the concentration of collagen?
hydroxyproline
what are some characteristics that can be used to classify epithelia?
number of cell layers, cell shape in superficial layer, and presence of specializations of plasma membrane
what are the 3 types of simple epithelia?
squamous, cuboidal, and columnar
what are the 4 types of stratified epithelia?
squamous nonkeratinized, cuboidal, columnar, and squamous keratinized
define pseudostratified epithelium
columnar cells that appear to be stratified, but there is in reality once cell that touches the basal membrane. the appearance of stratification is due to multiple nuclei
where can you find simple squamous cells?
blood-brain barrier, filtration areas, and exchange areas
where can you find simple cuboidal cells and what are the functions of simple cuboidal cells?
you can find them in thyroid follicles, renal tubules, and ducts of glands; they function in absorption, secretion, as barriers, and conduits.
where can you find simple columnar cells (ciliated and nonciliated)?
ciliated - uterine tubes; nonciliated - stomach and intestines
what is the function of simple columnar cells?
absorption, secretion, and as barriers
where will you find pseudostratified columnar cells (ciliated)? what is the function?
trachea, bronci, and ducts of male reproduction system (stereocilia are present; function in secretion, absorption, as barriers, and in transport
what are the 2 types of stratified squamous cells? where can you find them? Function?
keratinized (epidermis) and non-keratinized (esophagus, distal anal canal, vagina); they function as barrier and protection
what is a characteristic of squamous cell carcinoma?
keratin pearls
where can you find transitional epithelium? function?
ureters, urinary bladder, and urethra; barrier, protection, and distension
how does urine affect transitional epithelium?
when the bladder is empty, the cells are expanded/plump; as urine fills the bladder, the cells become distended
define metaplasia
the action in which psuedostratified cells become columnar cells to protect the body from something; ex: esophagus undergoes metaplasia in response to smoking. this protects the esophagus, but does not produce mucus anymore due to absence of cilia in pseudostrafied cells
name some specializations of the plasmalemma
cilia, flagella, microvilli, and stereocilia
what are the 3 types of cilia?
motile cilia, primary aka monocilium (nonmotile), and nodal cilia (motile)
describe the structure of a motile cilia
a 9+2 array made up of 9 pairs of microtubules surrounding 2 central microtubles; the 9 dublets are connected by dynein arms which are ATPases that allow it to be motile
what are some functions of primary aka monocilum (nonmotile)
serve as chemosensors, osmoreceptors, mechanoreceptors, mediate light, taste, and sound perception; pivotal role in normal tissue morphogenesis
explain the involvement of primary cilium in polycystic kidney disease
the primary cilium are used to sense fluid movement; in polycystic kidney disease you have a mutation in polycistin 1 and 2 that results in a change of orientation in the spindles. as a result, the tubules expand horizontally instead of vertically, creating cysts
where are nodal cilia located and what is their function?
nodal cilia are located in the primitive node; they are used to direct the movement of nodal in the development of the organism
contrast the structures of cilum and microvilli
cilium are larger and have microtubules in the core; microvilli are small and lack microtubles
define sterocilia (stereovilli) and give their location
stereocilia are elongated epithelium; they can be found in male reproductive ducts
describe the zona occludens
tight junction that extends along entire circumference of the cell; prevents material from taking paracellular route in passing from the lumen into the connective tissues
describe the zona adherens
basal to the sona occludens; E-Cad binds to each other in the intercellular space and to actin filaments intracellularly
describe the macula adherens
intermediate filaments; ecad is associated with plaques
gap junction
communicating junctions for small molecules and ions to pass between cells. couple adjacent cells metabolically and electrically
hemidesmasomes
attach epithelial cells to underlying basal membrane
what is the clinical significance of claudin?
claudin is a protein found in the zona occludens; mutations can result in excessive loss of magnesium ions in urine, brain cancers (claudin 5), and deafness (clauden 9)
what is the clinical significance of occludin?
h.pylori interferes with occludin (protein found in the zona occluden); cholera can interfere here as well, specifically in the intestines
what determines the degree of permeability in the zona occludens?
mixture of claudins to occludins; high claudin ratio leads to higher permeability
what is the skeletal filament of the zona adherens?
actin filaments
what is the skeletal filament of macula adherens?
intermediate filaments
what is another name for macula adherens?
desmosome
what holds adjacent cells together at the zona adherens?
e-cadherin
pemphigus
results in blisters; due to autoantibodies against desmogleins
what type of collagen is used to attach hemidesmosome to basal lamina/
type XVII
bullous pemphigoid
autoantibodies develop against type XVII collagen (BPAG2)
based on the general blueprint for junctional complexes, what component does integrin represent?
A: intracellular anchor (attachment) protein
B: Cell adhesion molecule (link protein)
C: cytoskeltal element
B: cell adhesion molecule (link protein)
nexus or gap junctions
made up of connexons, which are made up of 6 connexins each.
what is the clinical significance of gap junction abnormalities?
abnormalities can lead to female infertility, neuropathy, deafness, congenital cataracts, and cardiac arythmias
what is the clinical significance of clue cells?
points at bacterial vaginal infection
what is needed for metastasis?
absence of e-cad and extra adhesion molecules
