Path Flashcards
e- microscopy vs bright field microscopy vs fluorescent microscopy vs phase contrast microscope
pass e- thru specimen and look at the screen, smallest wavelength –> best resolution; can even use higher mag power; makes imgs look more “3D” vs white background d/t light source from bottom; casts a beam of light vs aka dark field microscope aka UV microscope; black background d/t no light source, you use UV light to look at fluorescent stains vs aka Nomarski interference microscope; casts light at an angle –> ring of light –> gives better contrast when looking at specimens w/ similar refractive index –> used for live or unstained specimens
relationship b/w wavelength, resolving power, and mag power
smaller wavelength –> better resolution; higher mag –> poorer resolution (like how you zoom in a photo and it looks pixelated)
all organs = composed of 2-4 basic tissues:
epithelial, connective, muscular, nervous tissues
resolving power def
capacity of lens to give separate imgs b/w objects that are very close together
how to cut super thin translucent specimens w/ paraffin and microtome (5-8 micrometers thick)
1) fixation - make cross-links w/ proteins to prevent degradation from post mortem decay –> carbs and lipids may be lost; or use formalin alc slns or rapid freezing
2) embedding - paraffin will infiltrate specimen BUT paraffin = hydrophobic so do these steps:
a) dehydration - remove water from specimen and pass specimen thru alc slns
b) clearing - pass specimen thru xylene or cedar wood oil to remove alc –> tissue = translucent
c) infiltrate specimen w/ melted paraffin –> let paraffin solidify –> specimen = embedded into paraffin
STEPS abc MAKE UP EMBEDDING
3) sectioning - cut thin sections of paraffin/specimen w/ microtome
4) mount section on slide –> remove embedding agent w/ alc –> put specimens in stains, counterstains, etc
alternative methods for making thin translucent sections (besides paraffin)
epoxy resin but harder to do and more to do; though you’ll get thinner sections (<1um thick) –> higher resolution
What are artifacts?
empty vesicles (think dentin/enamel example)
How do stains stick to specimen?
acidic stains bind w/ basic structures, basic stains bind w/ acidic structures. acidic structures = basophilic, basic structures = acidophilic
H&E vs PAS vs Mallory trichrome vs toluidine blue vs Prussian stains
hematoxylin (basic) stains nuclei –> purple, and eosin (acidic) stains cytoplasm –> pink. if not purple or pink –> mucus vs Periodic Acid Schiff; stains polysaccharides/complex carbs and proteoglycans vs stains connective tissue vs stains acidic components in shades of blue vs stains metal ions (heme/iron = most common)
immunocytochemistry
staining techniques that uses specificity of ab binding (ie: you can use labeled primary ab to stick to ag and then stain it, or use labeled secondary ab that sticks to primary unlabeled ab that sticks to ag and then stain it). ex: enzyme linked method, fluorescence method, metals for e- microscopy
What are epithelial tissues?
Derived from endo/ecto/mesoderm; line surfaces and cavities of body (skin, GI lining, hollow organs - outside vs lumen); no external matrix —> cell to cell contact —> cells = cohesive and make specialized junctions; attach to basement membrane. FOCUS ON SURFACE CELLS
What is basement membrane?
Consists of basal lamina (thin portion deep in epithelium) and reticular laminate (thick portion superficial to connective tissue; consists of reticular fibers —> need special stain to see under light microscope; secreted by connective tissue). Fibers of both lamina = intertwined —> connects epithelia to connective tissue —> provides barrier and filter exchange to underlying connective tissue
Are epithelial tissue vascular?
No, they rely on blood vessels in connective tissue
Can epithelial tissue regenerate?
Yes if not highly specialized. Most cancers = of epithelial origin (carcinomas). Adenocarcinoma = glandular epithelium tumor, papilloma = benign projecting from tumor, metaplasia = change from 1 tissue type to another
Simple squamous vs simple cuboidal & simple columnar vs pseudostratified vs stratified squamous vs stratified cuboidal/columnar vs transitional epithelia
Little cyto, 1 layer of flat cells, little to no abrasion, easily damaged b/c so thin —> can get infected from surgical procedures —> can be replaced by connective tissue (ex: endothelial lumen, lungs) vs absorption and/or secretion —> highly specialized (ex: kidney, glands), MICROVILLI vs they look stratified but each cell = actually in contact w/ basement membrane; function in secretion and have cilia (ex: URT, trachea) vs multiple layers, flattest nuclei at top (less stained), resists friction (can be keratinized to get more resistance to friction) (ex: skin, esophagus) vs extremely rare to find, usually in transition rom stratified to simple, function in secretion and/or absorption vs multiple layers, surface nuclei stay round instead of being flattened, significant expansion and reduction (ex: bladder and urinary system)
Cell adhesions: tight junctions vs gap junctions vs anchoring junctions
Aka occluding adhesion/zonula occludens, prevents material from seeping down onto b/w adjacent epithelial cells, prevents proteins from luminal surface to move to basal surface vs provide cytoplasmic passage of molec b/w adjacent cells (ions, signal transduction molec) vs link cytoskeletons of adjacent cells or link cytoskeleton to fibers of extra cellular matrix; they anchor cells together (ex: skin cells) —> resistance to shearing forces; diff types: zonula adherents, hemi/desmosomes, focal contacts; act like spot welds
Cell surface specializations: microvilli vs stereocilia vs cilia vs basal folds
Finger like projections on luminal surface, function to inc SA for max absorption, brush border/striated border appearance under light microscopy vs super long microvilli, same function as microvilli, lack microtubules that make up cilia —> poor organized motion (ex: sperm cells) vs specialized hair like projection the sweep fluid or material across epithelial surface, contain microtubules vs deep invaginations of basal surface, function to inc SA, have lots of mito in b/w folds —> basal striations
What are glands and secretory cells types: protein secreting vs mucin secreting vs steroid secreting
Organized group of epithelial cells that synthesize and secrete products; glands made up of 1+ type of secretory cell => “mixed”. Secretory cells = all either cuboidal or columnar. Aka serous glands, secrete protein, abundant in RER —>purple in H&E stain (lots of ribosomes made of protein and RNA in RER) vs aka goblet cells, mix of proteoglycans and glycoproteins that act as barriers or lubricants, stain light blue or frothy in H&E stain vs abundant in SER —> pink in H&E stain d/t cyto, lipid vacuoles don’t stain —> small clear openings in cyto
Secretary mechanism: exocrine vs endocrine
Products secreted thru apical cell membrane into a duct; merocrine - exocytosis releases material in vesicles to a duct, apocrine - material = pushed into cell surface —> cell membrane w/ bit of cyto pinches off into a vesicle, Holocrine - cell becomes distended in vesicles —> dies and is shed (ex: hair) vs products secreted thru basal cell membrane into blood vessels of underlying connective tissue
Parenchyma vs stroma of gland
Cells responsible for main function of gland/organ, often composed of epithelial cells vs supporting tissue w/in gland/organ, often composed of connective tissue
Structural types of glands: simple tubular vs simple acinar vs simple branched tubular vs cmpd tubular vs cmpd acinar vs cmpd tubuloacinar
1 branch or no branch (looks like test tube) vs cul de sac vs 2+ branches vs branch has branches vs each branch has cul de sacs vs each branch has both tubular and acinar branches and depends on where secretory portions and ducts are (sec portions reach higher)
What is connective tissue?
support, connect and/or separate other tissue types w/an an organ; all connective tissue = derived from embryonic mesenchyme/mesenchymal stem cells, small amounts remain in adults –> reappear and differentiate in wound healing; these cells also secrete and maintain variety of extracellular materials
-blast vs -cyte vs -clast
cells actively building/producing matrix vs cells actively maintaining matrix vs cells actively removing matrix
immune cells w/in connective tissues
mast cells - derived from basophils –> have abundant basophilic granules vs macrophages - derived from monocytes –> can be fixed or roaming –> become epithelioid cells when activated and clustered vs plasma cells - B cells secreting ab; have basophilic cyto and perinuclear neg Golgi imgs vs other WBCs
fibroblasts
primary and most abundant cell in connective tissues; spindle shaped but only nucleus = seen in stains –> oval shaped, finely granulated chromatin w/ 1-2 prominent nucleoli; responsible for fibers, glycoprotein and proteoglycan components of matrix
what is the matrix? what are the 2 components in matrix?
material that fills space b/w cells –> bulk of connective tissue mass. 1) ground substance - amorphous (w/o shape) material varying consistency from fluid to semisolid, sometimes solid in specialized connective tissue (ex: proteoglycans - large sugar/carb molec w/ some protein and lots of sulfate –> attracts H2O into matrix; nonfibrous glycoproteins - contain short branching carb chains attached to a protein –> mediate interaction b/w cells and extracellular matrix), and 2) fibers
what are all fibers made of? 3 types of fibers?
all = glycoproteins made and secreted by fibroblasts. collagen - fam of 27+ diff proteins made into triple helical structure to produce collagenous fibers, provide tensile strength –> bind structures together w/in body; synthesis complex (both intra/extracellular steps) vs reticular fibers (Type III collagen) - fine branching fibers forming loose mesh –> provides scaffolding to support other cells and structure of certain organs, component of reticular lamina, requires special stain w/ silver impregnation, does scars vs elastic fibers - allows tissue to recoil after stretching, can be cross linked to form sheets or filaments, requires special stain w/ aldehyde fuschin or neg img w/ H&E stain if big enough, made and secreted by smooth muscle cells
examples of specialized connective tissue?
bone, blood, cartilage
types of connective tissue proper: embryonic connective tissue vs areolar/loose irreg connective tissue vs reticular tissue vs adipose tissue vs dense irreg connective tissue vs dense reg connective tissue
mesenchyme - progenitor of all other connective tissue, mucous tissue - similar to mesenchyme except small collagen fibers = present vs packing, anchoring and/or embedding material in almost every organ of the body; contains typical components of connective tissue w/ matrix made of fluid-like ground substance w/ random collagen and elastic fibers; can replace other tissues physically after injury –> fibrosis, keloids, scleroderma vs branching network or reticular fibers that form framework of certain organs; fibers secreted by reticulocytes but other functional cells suspended w/in meshwork vs made of lipid storing cells called adipocytes embedded w/in reticular framework; the only connective tissue lacking matrix; always found in loose connective tissue except nervous system, lungs, eyelid, ears, penis, dorsum of hand; energy storage, thermal insulation and shock absorption; have 2 types: unilocular and multilocular; can be stained w/ Sudan stains or osmium tetroxide vs great abundance of large collagen fibers arranged randomly; contains few elastic an reticular fibers w/ very little matrix; forms tough fibrous sheets vs densely packed fibers running parallel to e/o
unilocular vs multilocular adipose tissue
yellow fat, lipids stored in 1 large vacuole that occupies majority of cell –> nucleus is pushed to the edge and cell has little cyto, more common in adults vs brown fat, lipids stored in small mult vacuoles –> cyto has FROTHY appearance, more common in babies, help w/ heat production since mito lacks ATPse and all energy production from Kreb’s cycle = lost as heat
def of lesion and 4 categories
structural abnmllity responsible for ill health. gross lesion - you see w/ eyes, can make dx vs microscopic lesion - looking under microscope vs ultrastructural lesion - look under e- microscope vs molecular lesion - looking at molec level (DNA, protein)
clinical manifestations: signs vs sxs
objective evidence of dz by examining physician vs subjective evidence of dz by pt
pathology classification of dz’s
congenital anomalies - occur before birth, happen in womb vs hereditary dzs - DNA abnmlities inherited from parent –> fhx vs inflamm dzs - immune system attacks own tissue (ex: graft rejection) vs degenerative dzs - tissue degenerates overtime (ex: arthritis) vs neoplastic dzs - ca, abnl growth
anatomical path and its 3 subspecialties
investigation and dx of dz from examining tissue; perform autopsies, microscopic exam of surgical biopsies, examine cytopath and hematology smear. surgical path, cytopath, forensic
surgical path vs cytopath vs forensic
study of tissue removed from living pts during surgery to dx dz, does bx’s vs studies and dx dz on cellular level, does cell collection vs does autopsies and frozen sections
def of bx. excisional bx vs incisional bx vs endoscopic bx vs punch bx vs shave bx. def of resection
removing sample tissue from body of living pt. entire mass/suspicious area (including surround skin) = removed vs portion of lesion = removed –> purely diagnostic –> have to f/u and remove the rest later prn vs endoscope = used to visually examine interior of canal or organ and remove tissue w/ forceps vs small cylindrical tube of tissue = removed, similar to incisional bx b/c you remove portion of it, seen in derm vs surgical/razor blade shaves lesion on epidermis or upper dermis, mostly seen in derm. removal of tissue en masse, often after bx confirming a dx
