IRREVERSIBLE CELL INJURY Flashcards
refers to the rapid death of a limited portion of an organism and is considered to be the final stage in irreversible degeneration.
NECROSIS
is the term used for the entire process of degeneration
and death of cells.
NECROBIOSIS
what are the 4 characteristics of necrosis?
- PALENESS OF TISSUE
- LOSS OF STRENGTH OF TISSUE AS IT SOFTENS
- DIFINTE ZONE OF DEMARCATION
- PATTERN OF THE LESIONS
morphologic appearance of necrosis
- DENATURE OF PROTEINS
- AUTOLYSIS
- TYPES OF NECROSIS
- COAGULATION NECROSIS
- LIQUEFACTIVE NECROSIS
- CASEOUS NECROSIS
- GANGRENOUS NECROSIS
- FAT NECROSIS
- INFARCTION
- ZENKERS DISEASE
most common manifestation of cell death, May result from acute deprivation of blood supply.
COAGULATION NECROSIS
gross appearance of coagulation necrosis
- PALE
- FIRM TEXTURE/ SWOLLEN/SHRUNKEN
microscopic appearance of coagulation necrois:
- original cell shape and tissue architecture preserved,
- CYTOPLASM- increased eosinophilia/hyalinized/calcified/
- NECROTIC CELLS- removed by WBC, PROTEOLYSIS & PHAGOCYTOSIS
3 PATTER of nuclear changes in couagulation necrosis:
1.KARYOLYSIS
2. PYKNOSIS
3. KARYORRHEXIS
the fading of nucleus
Karyloysis
shrunken & densely basophilic nucleic
PYKNOSIS
nuclear fragmentation
KARYORRHEXIS
4 ultrastructural appearance of coagulation necrosis:
- LOSS OF PROTEINS
- UNABLE RESTORATION OF ATP PRODUCTION
- SWELLING OF LYSOSOME
- CELL DEBRIES ARE REMOVED
necrosis occurs when enzymatic digestion of necrotic cells predominates over protein denaturation.
seen in bacterial infections due to attraction of neutrophils taht contains potent hydrolyses that are capable of digesting dead cells.
LIQUEFACTIVE NECROSIS
Gross appearance of liquefactive necrosis:
- TISSUE is LIQUEFIED
- BECOME SOFT TO VISCOUS FLUID
microscopic appearance of liquafactive necrosis;
- DEGENERATE NEUTROPHILS
- AMORPHOUS MATERIAL
this type of necrosis is typical lesion seen with specific bacterial diseases,
eg tuberculosis, caseous lymphadenitis.
CASEOUS NECROSIS
gross appearance of caseous necrosis:
- GREY WHITE
- DRY w/ FRIABLE PASTY TEXTURES
- CASEOUS= CHEESE LIKE
microscopic appearance of caseous necrosis
NECROTIC CELLS ‘do not’
1. consist of DEAD CELLS
2. retain CELLULAR OUTLINE
3. undergo COMPLETE DISSOLUTION
tissue appearance of caseous necrosis:
TISSUE becomes
1. SOFT
2. GRANAULAR TEXTURE
3. PALE YELLOW DICOLORATION
Clinical implication of caseous necrosis:
- lead to formation of ABSCESSES
- TISSUE DISTRUCTION
in this type of necrosis it occurs when saprophytic bacteria grow in necrotic tissue.
(distal limbs, digits, tips of ears)
GANGRENOUS NECROSIS
2 types of necrosis
- DRY GANGRENE
- WET GANGRENE
occurs in necrotized portion of the skin with “moisture loss “due to evaporation and drainage and presence of saprophytic bacteria.
DRY GANGRENE
when the coagulative necrosis of dry gangrene is modified by the liquefactive action of invading saprophytic / putrefactive bacteria. It’s called
WET GANGRENE
production of gas bubbles in the necrotic tissue by invading
bacteria (esp. Clostridia).
GAS GANGRENE
This type of necrosis distinguished by its location within body fat stores,
esp. abdominal or subcutaneous fat.
FAT NECROSIS
Gross appearance of FAT NECROSIS:
- FIRM
- HARD
- WHITE / CHALKY gritty areas
Fat necrosis are usually seen in?
PANCREATITIS
microscopic appearance of fat necrosis:
- CHOLESTEROL CLEFTS
- BASOPHILIC CALCIUM DEPOSITS
- surrounded by INFLAMMATORY CELLS
a form of coagulative necrosis resulting from a sudden deprivation of
blood supply. Commonly occurring in areas or organs with end artery
INFARCTION (ischemic necrosis)
a type of coagulative necrosis
in striated muscles characterized by loss of striations following necrosis.
ZENKER’S NECROSIS
Other terms used in association of necrosis:
- EROSION
- ULCER
- SLOUGH
is a SHALLOW AREA of necrosis confined to epidermis without scarring?
EROSION
an EXCAVATION of surface by necrosis and sloughing of the
necrotic debris and implies involvement of the tissue below the surface layer.
ULCER
-a piece of necrotic tissue SEPARATIONG from viable tissue.
SLOUGH
other term used in referrence of necrosis:
- MALACIA
- SEQUESTRUM
an area of liquefactive necrosis of the nervous tissue. Literally means
“SOFTENING”.
MALACIA
an isolated necrotic mass
, and this process is called sequestration
SEQUESTRUM
Lysis result to?
- CYST
- CAVITY
Secondary infection result to?
- ABSCESS
- GANGRENE
Resorption result to?
- GRANULATION TISSUE
- SCAR
Favorable outcome:
- formation of scar
- PETRIFACTION
- OSSIFICATION
- ASEPTIC AUTOLYSIS
UNFAVORABLE OUTCOME:
saprogenic fusion of necrotic tissue followed by: SEPSIS
derived from the Greek = “falling off”
APOPTOSIS
Apoptosis is involved in?
death of single cells (or small clusters) with intact cell
membranes and rapid removal by phagocytosis with little inflammation,
necrosis is involved in?
locally extensive areas with loss of cell membrane integrity,
enzymatic digestion and an inflammatory response
hybrid forms of cell death exist that share aspects of
necrosis & apoptosis
NECROPTOSIS
causes of apoptosis in physiologic:
CELL UNDERGO
1.PROGRAMMED CELL DEATH
2. HORMONAL INVOLUTION
3. IMMUNE SYSTEM
causes of apoptosis in pathologic:
- DNA DAMAGE
- MISFOLDED PROTEINS
- INFECTING AGENT
- IMMUNE RESPONSE
- PATHOLOGIC ATROPHY OF ORGAN
Morphologic features of apoptosis:
- CELL SHRINKAGE
- CHROMATIN CONDENSATION
- NUCLEAR FRAGMENTS
4.NO INFLAMAMATORY RESPONSE
Biochemical mechanism of apoptosis:
- SIGNALING PATHWAYS that initiate apoptosis
- CONTRO & INTEGRATION
- COMMON EXECUTION PHASE
- REMOVAL OF DEAD CELLS
Disorders associated with defective apoptosis
