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Intro
ex3 - histo
60
Medical
Professional
09/26/2011

Additional Medical Flashcards

 


 

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Term

Hematoxylin and Eosin (H & E)

Definition

-       Hematoxylin: (blue color), basic dye that is positively charged ( has OH group). Very likely to stain the nucleus (nucleus is negatively charged---due to negatively charged DNA)

 

-       Eosin (counterstain): (red Color), acidic dye that is negatively charged (has high tendency for donating its H’s). Likely to stain cytoskeletal structures such as plasma membrane.

Term

Verification of staining result: enzyme digestion

Definition

1.     Periodic acid-Schiff (PAS) reaction: PAS stains carbohydrate rich macromolecules (ex. Glycogen in liver). Staining should disappear upon the addition of amylase or diastase (enzyme that digest carbo-rich molecules)>> prove the validity of staining.

2.     Feulgen reation: similar to PAS. But stain DNA and use DNAse to verify. 

Term
how does X-gal report a color
Definition

it is cleaved by B-gal

 

can be useful as a reported gene by putting x-gal in with a gene of interest

Term
how does autoradiography work?
Definition
a radioactive part of a sample is placed by a photographic emulsion paper.  the sample is radioactivated and that radiation will turn any close silver ions to elemental silver.  this can now be visualized
Term

Atomic Force Microscopy:

Definition

1.     relatively new technique. It is used to look at live cell at electron microscopic resolution. Machine feels or scans the surface of the target object using tapping mode or contact mode to gather information. Computers generates pictures based on info gathered.

 

           

 

Term

Confocal scanning microscopy

Definition

1.     optical dissection and reconstruction. Similar to CAT scan. Different wavelengths of light used produce various laminations (different color). Main advantages include: (can visualized physiological changes, can produce 3D replication, this technique illuminate one point in cell and do not excite other tissues that it penetrates (thus causing no disruption)). 

Term

1.     Electron microscopy: 

Definition

Scanning electron microscope (SEM): blast heavy metal over things we want to visualized, and then use electron screening to detect object. This technique is used to visualize surface structure. This technique must be done in a vacuum.

Term
how to name tissue consisting of several epithelial cell types?
Definition
it is named for whichever type is on the surface layer
Term
where to find transitional epithelium?
Definition
the lining of the urinary system.   these cells' appearences change in response to environmental factors like pressure.  they appear more flat that usual when they are found lining the FULL bladder
Term
where to find endothelium?
Definition
in a simple squamous formation on the inside of vessels
Term
where to find mesothelium?
Definition

simple squamous lining the thoracic wall, heart, abdominal body cavities

 

this MESOderm

Term
what is mucosa membrane?
Definition
consist of a surface epithelium (with or without glands) and underlying connective tissue and muscle.  It lines those cavities that connect with the outside of the body; alimentary, respiratory and genitourinary
Term

what is Serous membrane

 

 

 

Definition

consists of a mesothelium plus supporting connective tissue (with a basal lamina between the two).  It contains no glands and lines the peritoneal, pleural and pericardial cavities.

Term
what is the necessity of basal lamina?
Definition
to provide an anchor for epithelial cells and connective tissue (lamina lucida).  it is non-cellular (protein/pol-saccharide) and made of filaments.  have a role in stimulating differntiation
Term

Junction types.  What are the differences

   1)     Zonulaoccludens 

    2)     Zonulaadherens

    3)     Macula adherens

Definition

 1)     Zonula occludens  - tight junctions between the lateral sides of cells, but they only exist in small areas and have selectivity as to their junction strength.  they are near the apical side of the cell

    2)     Zonula adherens - larger zones of tight junction that take up a lot of surface

    3)     Macula adherens - aka desmosomes.  point adhesions that can be anywhere on lateral side and add a lot of strength between neighboring cells

Term
difference between cilia and stereocilia
Definition

stereocilia are all the same height, are extra long (have candle flame like appearance)

 

they can be found in the epididymis, and hair cells of the ear

Term
difference between hyperplasia and hypertrophy?
Definition
plasia refers to an increasing population, while trophy can indicate just an increase in the volume of the cell(s).  hyperplasia often is indicative of cancer
Term
what is the difference between metaplasia and dysplasia?
Definition

metaplasia is the changing of a cell type appearance, perhaps to a more differentiated state.  it is usually reversible.

 

dysplasia refers to a progressive abnormal appearance of a cell type

Term
what is labile tissue
Definition

tissue that is constantly turning over and proliferating (ie. bone marrow and GI mucosa)

 

the other types are stable (arrested at G0) or permanent (do not proliferate)

Term
explain the difference between physiological and pathological
Definition

increased number of cells (hyperplasia) in the lactiferous ducts of the breasts of a 28 yo woman is likely to be physiological because she is young and her breasts can grow.

 

if this was seen in a 70 yo woman who has already gone through menopause, this would be a pathologic finding

Term
what is the pathological effect that happens the the sodium pump shuts down?
Definition
water started to enter the cells at a rate the cells can't handle.  lysis can occur.  this is reversible up until a point.  the uncontrolled swelling can lead to myocytolysis
Term
what is karyolysis?
Definition

basophilia of chromatin fades (the blue color fades) bc DNA is lost

 

it is lost because of degradation of endonucleases

Term
what is pyknosis?
Definition

nucleus shrinking down to nothing, become tight, solid basophilic mass

 

when this pykonotic nucleus undergoes fragmentation, it's called karyorrhexis

Term
Ca2+ role in intracellular injury?
Definition
If injury causes damage to mitochondria, then ATP sythesase goes down, which affects the pumping out of calcium.  If more intracellular calcium is present, the activity of cellular enzymes will be increased and this will cause membrane damage
Term
coagulative necrosis
Definition

architecture of dead tissues remains, but they are anucleated

 

this is because enzymes have degraded proteins, namely proteolysase, and there is nothing to clear the cells.  eventually, neutrophils will get them out of the tissue

 

a local area of this is known as an INFARCT

Term
liquefying necrosis
Definition
white area begin showing up in tissue because cells have been transformed to a viscous liquid.  bacterial infections can before necrosis like this and it also occurs in the CNS
Term
what is caseous necrosis
Definition

cheesy necrosis.

 

often seen in TB, lysed cells are inclosed in distinct inflammatory borders marked by granulomas

Term
where does fat necrosis occur?
Definition

in the pancreas bc lipases are activated.

 

saponification occurs because cleaved fatty acids combine with calicum to form a visible soapy mess

Term
explain fibrinoid necrosis
Definition
immune system regulated involving Ag-Ab binding complexes.  these complexes, along with fibrin leaking from vessels produces bright pink, amorphous H-E staining
Term

define:

 

rubor

calor

tumor

dolor

dunctio laesa

Definition

redness

warmth

swelling

pain (prostgladins responsible for this)

loss of function

Term
what is transudate?
Definition

it is the collection fluid in the interstiteum that is not in hydrostatic and oncotic equilibrium.  it is acellular with low specific gravity

 

edema

Term
what is exudate
Definition

it is the collection viscus fluid in the interstiteum with high cellularity and specific gravity

 

pus (rich in leukocytes and the debris of dead cells)

Term
what marks inflammation triggering
Definition

the release of histamines (stored in mast cells, causes permeability of venule) and NO (produced by endothelial cells), increased hydrostatic pressure, transudate

 

the next stage is increased vascular permeability and exudate can happen

Term
what will vasodialation cause in the inflammatory response?
Definition

decrease flow velocity, decreased fluid, increased RBCs (as well as leukocytes)

 

blood cells will tumble and stack (rouleaux) and aggregate internally while WBS will be displaced peripherally near the site of injury

Term
margination
Definition

leukocytes are slowed down (told to put their blinkers on) by selectins on endothelial cells near site of injury (expression is stimulated by TNF and IL-1 which are cytokines and are produced by activated macrophages)

 

adhesion is possible when TNF/IL-1 start expressing integrins  the neutrophil's native integrins get transformed into their high affinity state

 

margration between the cells is stimulated by chemokines which also come from neutrophils that have already passed through the cell layer and a circular cell-cell messaging cascade is created

Term

 a negative effect Pharmaceuitcals can have on margination process?

Definition
- corticosteroids, catecholamines, and lithium can inhibit adhesion molecules
Term
process of killing microbes or dead cells?
Definition

opsinization, opsinins are attached to cell surface so they can be identified by other cells (neutrophils have membrane receptors for these cells)


phagocytosis, if oxygen dependent, uses myeloperoxidase, if not, uses enzymes

-chronic granulomatous disease is absence of NADPH oxidase so foreign materials can be engulfed, but never destroyed



Term
types of acute inflamation
Definition

serious= transudate fluid, effusion, blisters

 

fibrinous= increased cellularity in fluid, mainly fibrin

 

suppurative (purulent)= exudative, pus (which is a bunch of dead WBCs, microbes, and debris), abscess

Term
what cells are acute inflammation spec?  chronic?
Definition

neutrophils

 

macrophages and leukocytes and plasma cells

Term
eosinophils
Definition
nPresent in immune/allergic rxns mediated by IgE and in parasitic infections
nContain granules with major basic protein which is toxic to parasites but also causes lysis of mammalian epithelial cells
Term
granulomatous inflammation
Definition
nChronic inflammation in which a cellular attempt is made to contain an offending agent that is difficult to eradicate, e.g. Mycobactera tuberculosis
nActivation of T lymphocytes leads to macrophage activation which can cause injury to normal tissues
nGranuloma – focus of chronic inflammation consisting of an aggregate of macrophages transformed into epithelial-like cells, surrounded by rim of mononuclear wbcs, especially lymphocytes and some plasma cells
Term
important growth factor TGF
Definition

promotes scarring

 

potent fibrogenic agent which simulates fibroblast chemotaxis

Term
what is angiogenesis?
Definition

branching of preexisting vessels at site of injury or by recruiting progenitor cells

 

NO promotes vasodialation while ****VEGF***** promotes vessel permeability so that endothelial cells can migrate to the point of action

Term
main features of phase 2 wound healing?
Definition

there is granulation of the tisssue

 

fibroblasts arrive to provide collagen formation

 

angiogenesis is taking place

 

whole process takes days to 3 weeks

Term
order of collagen addition for wound healing
Definition
starts with collagen III (first week, adds 10% strength) for immediate effects, but over the course of months, it is replaced by collagen I which is much stronger (adds 70-80% of original strength)
Term
what cells cause contraction of the wound site if there is not enough epithelial tissue on the exterior available to close the wound?
Definition
myofibroblasts.  they are fibroblasts with muscle like contractibility and they pull the edges of the healthy tissue together
Term
what does PDGF cause the migration of?
Definition
fibroblasts, smooth muscle cells, monocytes to inflammatory areas
Term

why is TGF-beta the most important fibrogenic agent: 

Definition
causes fibroblast migration and proliferation, increased synthesis of collagen and fibronectin, and decreased ECM degradation by MMPs
Term
what effect would prolonged released of cytokines like those in the inital immune response have on healing?
Definition
they would degrade any granulcyte activity, and there would be persistent tissue injury and inflammation
Term
what is a downside of using NSAIDs during wound healing?
Definition
platlet formation is impaired
Term
what is a rhabdomyosarcoma?
Definition

it's a malignant cancer of connective tissue affecting skeletal muscle.

 

an osteosarcoma affects actual bone

Term
what do adeno- tumors affect?
Definition
glandular tissue
Term
what does a leiomyoma affect?
Definition
smooth muscle
Term
what is the main determinant of tumor grading?
Definition
differentiation, how much it looks like its intended tissue
Term
what do you call a tumor which is not involving a basement membrane?
Definition
carcinoma in-situ
Term
what is a gene transformation where one mutation will cause cancer?
Definition
proto-oncogenes -> oncogenes
Term
Proto-oncogene examples
Definition
RET – point mutations associated with medullary thyroid carcinomas, adrenal and parathyroid tumors (MEN types 2A and 2B)
PDGFRB – translocations in certain leukemias
ERBB1 – overexpression present in squamous cell carcinoma of lung, gliomas
KIT – point mutation,  GI stromal tumors
Term
features of cushing syndrome, an endocrinopathy.
Definition
(lung carcinoma, small cell); excess production of corticotropin
Hypercalcemia,  osteolysis induced by cancer and  production of calcemichumoral substances by extraosseous neoplasms
Term
AcanthosisNigricans
Definition
Grey-black patches of verrucous hyperkeratosis on skin (e.g, axilla)
Can also be see in children genetically (benign)
Skin changes may occur before discovery of cancer
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