IntroPathologySSN Flashcards
Postmitotic
heart, nerve. Replaced by scar when injured
intermitotic
divide all the time. Rapid turnover. Intestine, epithelial, skin, bone marrow
reverting mitotic
usually don’t divide but can when injured. Hepatocytes, renal tubular eptothelium
lipofuscin
old age/wear-and-tear pgment in liver and heart
free radical injury
physical, radiation: breaks chromosomes, diarrhea, hair loss, low blood count
free radical damage in
S and G2, intermitotic cells particularly
types of free radicals
lipid peroxidation, protein cross-linking, DNA mutation, superoxide, hydroxyl, peroxide
cytopathic viral infections
interfere with cel metabolism
Immune-mediated viral damage
against virus or virus-altered cells
cytomegalovirus
in immune-supressed pt., cell becomes huge
two ways chemicals damage
directly combine with molecule or organelle, or reactive metabolite binds membrane protein or lipid
hypoxia/ischemia
lactic acid causes pH drop, causes ATPase disfunction, Na influx, swelling
reversible hypoxia
ER swells, mitochondria condense, ribosomes disaggregate, glycogen stores used up.
irreversible hypoxia
cell rupture
necrosis triggers
neutrophils
test for necrosis with
trypan blue binds cells in lab (not diagnostic)
gross necrosis
plase area with yellow and hemorrhage Nuclei disappear, incoming neutrophils, hypereosinophilic
caseous necrosis
whitelooking areas of necrosis
nuclear breakdown
pyknosis (enlarged), karyorrhexis (nucleus breakdown) karyolysis (small bits)
mitochondrial apoptosis
release superoxides, mito pores releases cytochrome C, causes caspase 9 and activates DNAases
Death-receptor apoptosis
cytoplasmic caspace 8 activation. T-cells bind FAS. Chromatin forms DNA ladders, Blebs form apoptotic bodies
acute inflammation: vascular phase
Dolor, rubor, calor, tumor, functio laesa
dolor (pain)
fleeting vasoconstriction (seconds); mediated by nerve endings
rubor (red) and calor (heat)
progressive vasodilation of arterioles, cap bed and venules increases blood flow
histamine, leukotrienes, bradykinin
rela arteriole smooth muscle
tumor and functio laesa
increase vascular permeability and hydrostatic pressure; leakage of fluids into interstitial space; edema
transudate
low cells, low protein. Duration of leak depends on endothelial injury
exudate
transudate after cellular phase. Cell and protein rich
assume neutrophils in exudate unless
allergy, drug rxn, parasite (eosinophil), or viral (lymphocyte)
acute inflammation: cellular phase
margination, rolling with transient adhesions. Firm adhesion, transmigration
margination
vasodilation slows blood flow, nuetrohils migrate to flow periphery
rolling with transient adhesions: P-selectin endothelia
histimine, thrombin, sialyl-Lewis X oligosaccharides, LAD-2 disease
rolling with transient adhesions: E-selectin endothelia
TNF, IL-1, sialyl-lewis X oligosaccharides, LAD-2 disease
firm adhesion: ICAM-1 endothelia
TNF, IL-1, LFA-1 (integrin), LAD-1 disease
firm adhesion: VCAM-1 endothelia
TNF, IL-1, VLA-4 (integrin)
transmigration PECAM-1 (CD-31) endothelia
collagenases (from neutrophils)
opsinization
how antibodies coat patholgens
opsonins
help host phagocytotic cells bind and destroy pathogen
TLRs
toll like receptors, are pattern recognition receptors that let innate immune cells (neutrophils) bind molecular motifs common to pathogens
PAMPS
pathogen associated molecular patterns, what TLRs on neutrophils recognize
neutrophil receptors
FcR, CR1, CR3, C1q, TLR4
FcR ligand
IgG (opsonin)
CR1, CR3 ligand
C3 (opsonin)
C1q ligand
Collectins (opsonin)
TLR4 ligand
LPS (a PAMP)
steps of opsination and destruction
- recognition and attachment 2. engulfment 3. phagosome 4. phagolysosome 5. destruction via reactive oxygen species
O2 to Superoxide, hydrogen peroxide, hydroxyl radical: enzymes and location
NADPH oxidase, mitochondria
Nitric Oxide (NO) enzyme and location
iNOS (+arginine) in cytoplasm
acute inflammation outcomes
resolve, abscess, turn to chronic inflammation (hours or days)
fibrinous exudate
forms on inflammed organs b/c tissue factos are released, causing extrinsic coagulation cascade
green in pus
comes from heme component of MPO
cytokines
mediate inflammation and immune response
TNF & IL-1
cytokines produced by macrophages that activate the endothelium
chemokines
recruit leukocytes (in inflammation states) and organize B and T-cells in the spleen and lymph nodes (in normal tissue)
Chemokine examples
**CC (adjacent cysteine residues) and CXC (cysteines separated by another amino acid)
lysosomal enzymes of leukocytes
mediate acute inflammation: proteases which act on kininogen and complemet proteins (c3, c5)
neuropeptides
small substances initiate inflammatory response
Nitric Oxide (NO) enzyme and location
Short-lived soluble free radical gas, causes smooth muscle relaxation and vasodilation
plasma protein derived mediators
produced in liver and present in blood inactive. Complement activation ( C3a, C5a, C3b, C5b-9) and factor XII (kinin system)
plasma proteins
C1-C9 play role in host defense and inflammation
membrane attack complex
C5-C9, degrade membrane for cell lysis
complement activation pathway: classical
Ag-Ab complexes; IgG/IgM
complement activation pathway: alternative
bacterial polysaccharides
complement activation pathway: lectin
binds mannose residues microbes
systemic effects of inflammation: exogenous pyrogens
macrophages release TNF and IL-1 ->cyclooxygenase increase, prostaglandin production
systemic effects of inflammation: increase in acute phase proteins
liver production of C reactive protein, serum amyloid A, fibronogen
C reactive protein
CRP, opsonization
serum amyloid A
SAA, opsonization
fibrinogen
increases erythrocyte sedimentation rate
systemic effects of inflammation: leukocytosis
increase of WBCs from bone marrow
chronic inflammation causes
caused by infection or de novo from chronic disease
chronic inflammation involves
lymphocytes, plasma cells and macrophages (not neutrophils of acute)
granulomas
activated macrophages plus T-cells, eosinophils, around an indigestible antigen or as part of a type IV hypersensitivity response
granulomas lead to
chronic scarring/fibrosis/calcification
granuloma serious clinical problems
schistosomiasis, sarcoidosis, inflammatory bowel disease
types of granuloma
infectious (parasitic, fungal, bacterial), foreign body, unknown, miscellaneous
caseating granulomas
necrotizing, as in TB, less clear borders, denucleiated ded cells
noncaseating granulomas
as in sarcoidosis, macrophages, giant cells, clear border (surrounded by lymphocytes)
platelets
bud off megakarocytes. Replace every 10 days. 6 day shelf life.
platelets cause vasoconstriction
by releasing ADP/thromboxane A2 (TxA2)
thrombocytopenia
less than 150,000 platelet count, need transfusion
platelet plug formation
adhesion, activation, aggregation
vWF (adhesion)
Cross-linked dimers bind collagen and platelets
A3 domain
where vWF binds collagen exposed at site of injury
Gp1b receptor (A1 domain)
where vWF binds platelet
ADAMTS13
cleaves vWF multimers at A2 (to minimize clot size
defects in vWF
von Willebrand disease: easy bruising, nosebleeds, dental bleeding, menorrhagia
von Willebrand type I
low vWF. Most common form
von Willebrand type II
AD or AR, may not bind VIII, platelets correctly
vonW type 2M
A1 loF mutation. Platelets can’t bind. (GeI=NL; ristocetin=no clumping)
vonW type 2A
defects in A2/crosslinking
vonW type 2B
A1 GoF (increased A1/Gp1b interaction). Clotting in general circulation, less avail for injury
vonW type 2N
poor binding to VIII
von Willebrand type 3
AR, no vWF syth so VIII is very low. Rare.
thrombotic thrombocytopenic purpura (TTP)
lack of ADAMTS13 leads to spontaneous clotting
5 signs of TTP
microangiopathic hemolytic anemia, low platelets, neuro, renal, fever.
TTP affects
Young adults, mainly female. High mortality if untreated
Congenital TTP
AR, rare, no ADAMTS13. Neonatal jaudice, some present as adults. Give FFP (contains ADAMTS13)
acquired TTP
autoimmune, Abs to ADAMTS13. Treat with plasmapheresis
acquired TTP induced by
clopidogrel
platelet activation
stabilizes adhesion. Platelets spread on top of wound