Test 1 Flashcards
What are the 5 pathological processes?
- Degeneration/ Necrosis
- Inflammation and repair
- Circulatory disorders
- disorders of Growth
- Deposits and Pigmentation
Define etiology
Cause
Define Pathogenesis
Sequence of events from initial stimulus to ultimate expression of disease
Define Molecular and morphologic changes
biochemical and structural alterations induced in cells and organs of the body
Define Clinical manifestations
clinical signs resulting from functional abnormalities of affected tissues
What is general pathology
the main pathological processes incited by various injurious stimuli. applies to cells/tissues/organs
what is systemic pathology
System-specific disease processes
what is the difference between morphologic diagnosis and etiologic diagnosis
Morphologic- includes pathological process, location, distribution, duration and severity.
Etiologic - includes pathological process, location and cause
what are areas to avoid when doing a necropsy?
- areas accessible to animals
- areas which may contain food
- high traffic areas
- areas difficult to disinfect
what is the most common route of exposure to pathogens during a PM?
oral
what is BSL?
biosafety levels
What are the steps for doing a PM for any species?
- external examination
- open the body cavities
- collect microbiologic samples
- remove and dissect organs
- collect histologic samples
Which organ do you sample last?
intestines
How do you confirm sepsis with culture?
culture multiple organs
What would you use a red top or plain sterile tube for?
Culture
What would you use an EDTA tube for?
fluid analysis and cytology
What is the formalin:tissue ratio?
10:1
How far does formalin penetrate tissue?
no more than 1/2 cm
Define autolysis
self-digestion or degradation of cells and tissues by the hydrolytic enzymes normally present in tissues
Define Putrefaction
process by which post mortem bacteria break down tissues
which tissues autolyze the quickest?
Gastrointestinal tract, pancreas, gall blader
what does the rate of decomposition depend on?
- cause of death
- environmental and body temp
- microbial flora
The presence of _____ is the most likely to be microscopically obscured by decomposition:
a) cell injury (necrosis)
b) foreign material
c) infectious agents
d) inflammation
e) neoplasia
A. cell injury (necrosis)
What is rigor mortis
Contraction of the muscles after death
What is livor mortis
discoloration of organs from blood being pulled by gravity after death. effects the side of the animal facing the ground
What are the differences between antemortem blood clot and post mortem blood clot?
antemortem clot: attached to vessel of walls dry and dull lamellated friable Postmortem clot: unattached shiny and wet elastic perfect cast of vessel lumen
Hemoglobin imbibition is caused by what?
freezing
what is hemoglobin imbibition?
red staining of tissue, especially the intima of heart, arteries and veins
what is bile imbibition?
bile in the gallbladder starts to penetrate the wall and stains the adjacent tissues
what is bloat?
postmortem bacterial gas formation in the lumen of the GI tract
Who will bloat faster: Herbivores or carnivores?
herbivores
What is pseudomelanosis?
greenish-black discoloration of tissues post mortem.
What is the difference beetween a description and morphological Dx?
Description: describes what you see precise word picture MDx: interprets the description and makes subjective conclusions
What does No SLo DiSCo CoMas stand for?
Number, size, location, distribution, shape, color, consistency, margins/surface
Define focal
One isolated lesion
Define Multifocal
numerous similar lesions that can be of variable size
Define diffuse
throughout a large portion of the effected tissue
Define multifocal- coalescing
Multiple lesions that are touching
what can well demarcated tissue tell you?
- The lesions represents a different tissue (tumors)
- Infarcts
- chronic lesion with fibrous capsule
What can poorly demarcated tissue tell you?
- the lesion and adjacent tissue may be similar
2. the process is gradually infiltrating into the normal tissue; is poorly contained
Define Atrophy
decrease in size and/or number of the cells and their metabolic activity after normal growth has been reached
Define Hypoplasia
incomplete development or underdevelopment of an organ or tissue
Define Hypertrophy
increased size of cells and their functions
Which cells exhibit hypertrophy?
Stable or permanent cells: cardiomyocytes, neurons
Define hyperplasia
increase in the number of cells of an organ
Which cells exhibit hyperplasia?
cells capable of replication: ie epidermis, respiratory mucosa
Define metaplasia
change in phenotype of a differentiated cell
Metaplasia is most often in which type of cells?
epithelial
Define dysplasia
alteration in shape, size and organization
What are the most common causes of acute cell swelling?
hypoxia and toxic agents
Histological appearance of cellular swelling
- H2O uptae dilutes the cytoplasm making the cells enlarged with pale cytoplasm.
- May show increased cytoplasmic eosinophilia
nucleus in normal position, with no morphological changes
What are the ultrastructural changes of cellular swelling?
- plasma membrane alterations
- mitochondrial changes
- dilation of the ER
- nuclear alterations
Define fatty change
sub-lethal cell damage characterized by intracytoplasmic fatty vaculation
What are the main causes of fatty change?
hypoxia, toxicity, metabolic disorders
Histological appearance of fatty change
Well delineated, lipid-filled vacuoles in the cytoplasm, , may displace the cell nucleus to the periphery
what causes cell death after irreversible cell injury?
hypoxia, ischemia, and direct cell membrane injury
Gross appearance of necrosis
pale, soft, friable and sharply demarcated from viable tissue by a zone of inflammation
histological appearance of necrotic cells
- increase binding of eosin
- loosing basophilia
- glassy homogeneous
- vacuolation and moth eaten appearance
- calcification may be seen
Coagulative necrosis is common caused by ____ in all solid organs except _____
ischemia; brain
Which form of necrosis has dead cells that are “digested”
liquefactive necrosis
Liquefactive necrosis occurs in which kind of tissues
- Tissue with high neutrophil recruitment & enzymatic release with digestion of tissue
- tissues with high lipid content
What prefix do you use for describing white matter?
Leuko
What prefix do you use for describing gray matter?
polio
Leukoencephalomalacia affects which species?
horse, chicken and pig
Polioencephalomalacia can be caused by?
1 Thiamine deficiency diet 2 increased ruminal thiaminase activity 3 administration of thiamine analogs 4 high levels of sulfur in diet or water 5 lead toxicity 6 thiaminase containing plants
Pus is associated with which necrosis?
liquefactive
What is a localized collection of pus in a cavity formed by disintegration of tissues surrounded by fibrous connective tissue
Abscess
What are the two types of abscesses?
Septic and sterile
histological appearance of liquefactive necrosis
1 loss of cellular detail 2 cells are granular 3 eosinophilic and basophilic debris 4 neutrophil nuclei may dominate nuclear debris 5 no tissue architecture is preserved
Which form of necrosis begins mostly as coagulative necrosis?
Gangrenous necrosis
what is the difference between “dry” and “wet” gangrene?
Dry gangrene- no bacterial superinfection; tissue appears dry
Wet gangrene- Bacterial superinfection has occurred; tissue looks wet and liquefactive
What necrosis looks cheese like?
caseous necrosis
Caseous necrotic debris represents _______
dead WBCs
What are the 3 types of fat necrosis?
1 enzymatic necrosis
2 traumatic necrosis of fat
3 necrosis of abdominal fat
Enzymatic necrosis is also known as?
pancreatic necrosis of fat
Which form of necrosis is usually seen in immune reactions involving blood vessels?
fibrinoid necrosis
Fibrinoid necrosis occurs when _____ are deposited in the walls of arteries
Ag-Ab complexes
Define apoptosis
a pathway of cell death
induced by a tightly regulated suicide program
True/ False
Apoptosis causes inflammation
False:
there is no inflammation associated with apoptosis
What are the functions of the plasma membrane?
selective barrier
structural base for enzymes and receptors
Which phospholipid sends signals to phagocytes for ingestion?
Phosphatidylserine
What are the functions of proteins and glycoproteins?
- ion and metabolite transport
2 fluid phase and receptor-mediated uptake of macromolecules
3 cell-ligand, cell-matrix, and cell-cell interactions
What are the 4 general arrangements of proteins and glycoproteins?
1 integral/ transmembrane
2 protein sysntehsized in cytoplasm and linked inot membrane via lipids or cholesterol
3 inserted through GPI-linked proteins
4 non-covalent associations
Define passive transport
molecules move down a concentration or electrical gradient
Define active transport
molecules move against a gradient, requires ATP
Which types of molecules can passive diffuse across the plasma membrane?
1 Small non-polar molecules
2 hydrophobic molecules
3 polar molecules <75 Daltons
What are ways to transport larger molecules across the plasma membrane?
Channels
Carriers
What are the two major forms of endocytosis?
potocytosis
pinocytosis
What are the 3 major classes of the cytoskeleton?
1 actin microfilaments
2 intermediate filaments
3 microtubules
Which is the thinnest filament of the cytoskeleton?
actin microfilament
What are the functions of actin microfilaments?
In muscle cells: muscle contraction via association with myosin
In non-muscle cells- control cell shape and movement
What are the functions of microtubules?
connecting cables for molecular motor proteins
participate in sister chromatid separation during mitosis
adapted to form motile cilia of flagella
What are the functions of tight junctions?
create a continuous barrier that is highly resistant to paracellular ion movement
helps maintain cell polarity by allowing the segragation of apical and basolateral domains of cells
What are the functions of desmosomes?
mechanically attach cells and their intracellular cytoskeletons to other cells of the extracellular matrix
What are the functions of gap junctions?
mediate the passage of chemical or electrical signals from one cell to another
pores that permit passage of small molecules
critical in cell-cell communication
what is the function of the endoplasmic reticulum?
site of synthesis of all transmembrane protein and lipids
initial site for the synthesis of all exported molecules
Which endoplasmic reticulum has no ribosomes?
smooth endoplasmic reticulum
what is the function of ribosomes?
translate mRNA into proteins
What part of the cell is responsible for sequestering intracellular calcium?
Smooth endoplasmic reticulum
Proteins and lipids destined for other organelles or extracellular export are shuttled to the ________
Golgi apparatus
Which enzyme degrade cytosolic proteins, denatured or misfolded proteins, and other macromolecules?
Proteasomes
What are the functions of mitochondria?
Site of aerobic metabolism
regulator of apoptosis
Define euchromatin
uncoiled, transcriptionally active
Define Heterochromatin
coiled, transcriptionally inactive
What is the function of the nucleolus?
synthesis of rRNA
What is anoxia?
no O2 delivery to a tissue
What are the 6 major mechanisms of cell injury?
1 decrease ATP 2 mitochondrial damage 3 entry of Ca2+ 4 increase ROS 5 membrane damage 6 protein misfolding, DNA damage
What are the 2 primary metabolic pathways in which ATP is produced?
aerobic: TCA cycle and ETC
anaerobic: Glycolysis
What are the 3 major consequences of mitochondrial damage?
1 Formation of the mitochondrial permeability transition pore
2 increased production of reactive oxygen species
3 activation of apoptotic pathways
what enzyme are activated during accumulation of calcium?
- Phospholipases
- protease
- endonuclease
- ATPase
what are the major forms of damage from accumulation of calcium?
- membrane damge
- nuclear damage
- ATP depletion
In what ways are reactive oxygen species formed?
- normal metabolic processes
- absorption of radiant energy
- inflammation
- transition metals
- nitric oxide
How are free radicals removed?
- spontaneous decay
- antioxidants: Vit E, Vit A, gluthathione
- storage and transport proteins
- enzymes
What are the pathological effects of free radicals?
- lipid peroxidation in membranes causes extensive membrane damage
- oxidative modification of proteins causes damage to active sites, change conformation, and enhance degradation
- lesions in DNA causes cell aging, malignant transformation
What are the consequences of membrane damage?
- mitochondrial membrane damage- open the MPTP, decreases ATP
- plasma membrane damage- loss of osmotic balance
- injury to lysosomal membrane- leakage of enzymes into the cytoplasm
