CONT. LEC MOD 1 UNIT 2 Flashcards
the morphologic hallmark of irreversible injury and necrosis
nuclear changes
a nuclear change characterized by chromatin clumping and shrinking with increased basophilia
pyknosis
a nuclear change characterized by fragmentation of chromatin
karyorrhexis
a nuclear change characterized by fading of chromatin material and disappearance of stainable nuclei
karyolysis
necrotic cells are removed by
heterolysis by infiltrating leucocytes
A localized area of coagulative necrosis is called an
infarct
a pattern of necrosis which results in characteristic digestion, softening, and liquefaction of tissue.
liquefactive necrosis
ischemic injury to the CNS results in gangrenous necrosis. T or F
False. Liquefactive necrosis
After the death of CNS cells, liquefaction is caused by AUTOLYSIS
The necrotic material in liquefactive necrosis is caramel yellow because of the presence of pus. T or F
False. creamy gurl.
It is seen in focal bacterial or occasionally fungal infections that stimulate inflammation and in suppurative infections characterized by the formation of pus (liquefied tissue debris and neutrophils) by heterolytic mechanisms.
liquefactive necrosis
a pattern of necrosis which occurs as part of granulomatous inflammation and is a manifestation of partial immunity caused by the interaction of T lymphocytes (CD4+, CD8+, and CD4-CD8-), macrophages, and probably cytokines, such as interferon-γ, derived from these cells
caseous necrosis
Caseous necrosis combines features of both fibrinoid necrosis and liquefactive necrosis. T or F
False. coagulative necrosis and liquefactive necrosis
why is caseous necrosis named like this?
it has a cheese-like (caseous) consistency, a friable
white appearance on gross examination
caseous necrosis has an amorphous eosinophilic appearance on histologic examination. T or F
True
pneumonia is the leading cause of caseous necrosis. T or F
False tuberculosis
Gangrenous necrosis most often affects the lower extremities or bowel and is secondary to vascular occlusion (blockage of blood vessel). T or F
True
Not a specific pattern of cell death but is a commonly used term in clinical practice wherein it is usually applied to a limb, generally the lower leg that has lost is blood supply
gangrenous necrosis
When complicated by infective heterolysis and consequent liquefactive necrosis, gangrenous necrosis is called liquid gangrene. T or F
False wet gangrene
When characterized primarily by coagulative necrosis without liquefaction, gangrenous necrosis is called coagulated gangrene. T or F
False. dry gangrene
When infection is caused by Clostridium perfringens which produces gas and a feeling of crepitus it is called gas gangrene. T or F
True
A pattern of necrosis which is often associated with immune-mediated vascular damage.
Fibrinoid necrosis.
Occurs when complexes of antigens and antibodies are deposited in the walls of arteries. There is deposition of fibrin-like proteinaceous material in the arterial walls that appears to be smudgy and acidophilic.
2 forms of fat necrosis
traumatic fat necrosis
enzymatic fat necrosis
It occurs after a severe injury to tissue with high fat content, such as the
breast.
traumatic fat necrosis
a complication of acute hemorrhagic pancreatitis (a severe
inflammatory disorder of the pancreas)
enzymatic fat necrosis
- involves proteolytic and lipolytic pancreatic enzymes diffuse into inflamed tissue and literally digest the parenchyma.
- Fatty acids are then liberated by the digestion of fat and form calcium soaps (saponification, or soap formation). Vessels are eroded, with resultant hemorrhage.
- Appear as grossly visible chalky- white areas which enable the surgeon or the pathologist to identify the lesion.
- Histologic morphology: necrosis takes the form of shadowy outlines of necrotic fat cells with basophilic calcium deposits surrounded by inflammatory reaction
an orderly cell death which causes the cell to shrink and condense to disassemble its cytoskeleton and alter its cell surface so that phagocytic cells can attach to it and digest it rapidly before any leakage of its contents occurs, and neighboring cells usually remain healthy
apoptosis
apoptosis greek term for
falling away from
purpose of apoptosis
- Eliminate cells that are no longer needed.
- Maintain a steady number of various cell populations in tissue
Progression is through a series of changes marked by a lack of inflammatory response include blebbing of plasma membrane, cytoplasmic shrinkage, and chromatin condensation
apoptosis
In apoptosis, there is also involution and shrinkage of affected cells and cell fragments, resulting in small round eosinophilic masses often containing chromatic remnants as exemplified by
councilman bodies in viral hepa
physiologic apoptosis
- Destruction of cells during embryogenesis, implantation, organogenesis, developmental involution, and metamorphosis
- Involution of hormone dependent tissues upon hormone withdrawal, such as endometrial cell breakdown during menstrual cycle, ovarian follicular atresia in menopause, regression of lactating breast after weaning, prostatic atrophy after castration.
- Cell loss in proliferating cell populations, such as immature lymphocytes in the bone marrow and thymus and B lymphocytes in germinal centers that fail to express useful antigen receptors, and epithelial cells in intestinal crypts, so as to maintain a constant number (homeostasis)
-Elimination of potentially harmful self-reactive lymphocytes, either before or after they have completed their maturation, to prevent autoimmune
reactions.
-Death of host cells that have served their useful purpose, such as neutrophils in an acute inflammatory response and lymphocytes at the end of an immune response. In this case they are deprived of necessary survival signals, such as growth factors
pathologic apoptosis
-DNA damage, Radiation, cytotoxic anticancer drugs and hypoxia can
damage DNA, either directly or by production of free radicals. If repair
mechanism cannot cope with the injury, the cell triggers intrinsic mechanisms that induce apoptosis. Elimination of the cell is a better alternative than risking malignant transformation.
-Accumulation of misfolded proteins, improperly folded proteins arise from
mutations in the genes encoding these proteins or because of extrinsic factors such as damage caused by free radicals. Excessive accumulation of these misfolded proteins in the ER is called ER STRESS, culminates in apoptotic cell death. Apoptosis caused by accumulation of misfolded proteins has been invoked as the basis of several degenerative diseases of the CNS and other organs.
-Cell death in certain infections, particularly viral infections, in which loss of
infected cells is largely due to apoptosis that may be induced by the virus
(adenovirus and HIV infections) or by the host immune response (as in viral
hepatitis). This is a T cell mediated response to viral proteins in an attempt to eliminate reservoirs of infection.
-Pathologic atrophy in parenchymal organs after duct obstruction, such as in the pancreas, parotid gland and the kidney
Necrosis caused by accumulation of misfolded proteins has been
invoked as the basis of several degenerative diseases of the CNS and other organs. T or F
False. Apoptosis
cells smaller, cytoplasm is denser and the organelles, although
relatively normal, are more tightly packed represents what morphology of apoptosis
cell shrinkage
This is the most characteristic feature of apoptosis wherein chromatin aggregates peripherally under the nuclear membrane, into dense
masses of various shapes and sizes.
chromatin condensation
Plasma membranes are thought to remain intact during necrosis until the last stages hence, do not spill their contents into extracellular environment
and usually do not trigger inflammation and keeps neighboring cells healthy. T or F
False. necrosis
4 main pathways of abnormal intracellular accumulations
- Inadequate removal of a normal substance secondary to defects in mechanisms of packaging and transport (fatty change)
- Accumulation of an abnormal endogenous substance as a result of genetic or acquired defects in its folding, packaging, transport, or secretion (mutated forms of a1-antitrypsin)
-Faillure to degrade a metabolite due to inherited enzyme deficiencies
(storage diseases)
-Deposition and accumulation of an abnormal exogenous substance when the cell has neither the enzymatic machinery to degrade the substance nor the ability to transport it to other sites
characterized by the accumulation of intracellular parenchymal triglycerides and is observed most frequently in the liver, heart, kidney
fatty change
fatty change results from
- decrease production of APOPROTEINS required for transport
- overproduction fat cells
- increased transport of triglycerides to affected cells
Fatty change is thus linked to the disaggregation of ribosomes and consequent decreased protein synthesis caused by failure of ATP production in CCl4- injured cells. T or F
True
used by cells to synthesize cell membranes
cholesterol
The extracellular cholesterol may crystallize in the shape of long needles, producing quite distinctive clefts in tissue sections. T or F
False. cholesterol esters
plaques, smooth muscle cells and macrophages within the
intimal layer of the aorta and large arteries are filled with lipid vacuoles, most of which are made up of cholesterol and cholesterol ester
atherosclerosis
Intracellular accumulation of cholesterol within macrophages is also characteristic of acquired and hereditary hyperlipidemic states
xanthomas
-Clusters of foamy cells are found in the subepithelial connective tissue of the skin and in tendons, producing tumorous masses known as xanthomas.
This refers to the focal accumulations of cholesterol-laden macrophages in
the lamina propria of the gallbladder.
cholesterolosis
This lysosomal storage disease is caused by mutations affecting
an enzyme involved in cholesterol trafficking, resulting in cholesterol accumulation in multiple organs
niemann-pick disease, type C
What are the Intermediate filaments, which provide a flexible intracellular scaffold that organizes the cytoplasm and resists forces applied to the cell,
keratin filaments (characteristic of epithelial cells) neurofilaments (neurons) desmin filaments (muscle cells) vimentin filaments (connective tissue cells) glial filaments (astrocytes)
The neurofibrillary tangle found in the brain in Alzheimer disease contains glial filaments. T or F
False. neurofilaments
Certain forms of amyloidosis fall in this category of diseases. These disorders are sometimes called proteinopathies or protein-aggregation diseases
aggregation of abnormal proteins
example of intracellular hyaline deposits
reabsorption droplets, russell bodies, alcoholic hyaline (composed of keratin intermediate filaments)
Glycogen is found in renal tubular epithelial cells, as well as within liver cells, β cells of the islets of Langerhans, and heart muscle cells. T or F
True
In these diseases enzymatic defects in the synthesis or breakdown of glycogen result in massive accumulation, causing cell injury and cell death
glycogen storage diseases, or glycogenoses.
most common exogenous pigment
carbon (coal dust)
- Accumulations of this pigment blacken the tissues of the lungs (anthracosis) and the involved. lymph nodes
- In coal miners the aggregates of carbon dust may induce a fibroblastic reaction or even emphysema and thus cause a serious lung disease known as coal worker’s pneumoconiosis
an insoluble pigment, also known as lipochrome or wear-and-tear pigment.
lipofuscin
it is derived through lipid peroxidation of polyunsaturated lipids of subcellular membranes. Also, it is composed of polymers of lipids and phospholipids in complex with protein
lipofuscin
its being a telltale sign of free radical injury and lipid peroxidation
lipofuscin
fuscus (latin)
brown (brown lipid)
In tissue sections it appears as a yellow brown, finely granular cytoplasmic, often perinuclear, pigment
lipofuscin
It is seen in cells undergoing slow, regressive changes and is particularly prominent in the liver and heart of aging patients or patients with severe malnutrition and cancer cachexia
lipofuscin
This pigment is formed from tyrosine by the action of tyrosinase, synthesized in melanosomes of melanocytes within the epidermis
melanin
Decreased melanin pigmentation is observed in albinism and vitiligo. T or F
True
This pigment is a catabolic product of the heme moiety of hemoglobin and, to a minor extent, myoglobin.
bilirubin
In various pathologic conditions, bilirubin accumulates and stains the blood, sclera, mucosae, and internal organs, producing a yellowish discoloration called
jaundice
jaundice associated with destruction of red cells
hemolytic jaundice
jaundice associated with parenchymal liver damage
hepatocellular jaundice
jaundice associated with intra- or extrahepatic obstruction of the biliary
tract.
obstructive jaundice
a hemoglobin-derived, golden yellow-to-brown, granular or crystalline pigment that serves as one of the major storage forms of iron
hemosiderin
Iron is normally carried by specific transport protein
transferrins
Ferritin is a constituent of most cell types. When there is a local or systemic excess of iron, ferritin does not form hemosiderin granules, which are easily seen with the light micro. T or F
False, they form hemosiderin granules
Hemosiderin pigment represents aggregates of ferritin micelle. T or F
True
The best example of localized hemosiderosis is
common bruise
Local or systemic excesses of iron cause hemosiderin to accumulate within cell
True
After removal of iron, the heme moiety is converted first to biliverdin (“red bile”) and then to bilirubin (“green bile”).
False. biliverdin = green bile
bilirubin = red bile
the iron released from heme is incorporated into ferritin and eventually
hemosiderin.
True
causes of hemosiderosis
-increased absorption of dietary iron
-hemolytic anemias, in which abnormal quantities of iron are released from
erythrocytes
-repeated blood transfusions because the transfused red cells constitute an exogenous load of iron
