lab

Question 1

A form of cell death in which cellular membranes fall apart and cellular enzymes leak out and, ultimately, digest the cell.

Answer 1

Necrosis

Question 2

Elicits a local host reaction (inflammation) that is induced by substances released from dying or dead cells.

Answer 2

Necrosis

Question 3

Often the culmination of irreversible cell injury that cannot be corrected.

Answer 3

Necrosis

Question 4

Shows increased eosinophilia due to increased binding of eosin to denatured cytoplasmic proteins and loss of basophilic RNA in the cytoplasm
Loss of glycogen particles.
Prominent myelin figures.

Answer 4

Cytoplasm Changes during Necrosis

Question 5

nuclear shrinkage

Answer 5

Pyknosis (nucleus changes during necrosis)

Question 6

fragmentation of the pyknotic nuclei

Answer 6

Karyorrhexis (nucleus changes during necrosis)

Question 7

nucleus and DNA fades due to DNAse activity.

Answer 7

Karyolysis (nucleus changes during necrosis)

Question 8

(nucleus changes during necrosis)

Answer 8

Pyknosis
Karyorrhexis
Karyolysis

Question 9

The underlying tissue architecture is preserved for several days.
Affected tissues take on a firm texture
Injury denatures enzymes blocking proteolysis of dead cells – eosinophilic, anucleate cells persist
Leucocytes are recruited to the site of necrosis.
Cellular debris are removed by phagocytosis
Characteristic of infarcts in all solid organs except the brain.
example: kidney

Answer 9

Coagulative Necrosis

Question 10

Seen in focal bacterial and fungal infections
Because microbes stimulate the accumulation of inflammatory cells.
Enzymes of leukocytes digest the tissue.
The dead cells are completely digested, transforming the tissue into a liquid viscous mass.
The digested tissue is removed by phagocytosis
If the process was initiated by acute inflammation – the material is creamy yellow
Pus
Seen in abscesses
Ischemic destruction of brain tissue
example: heart

Answer 10

Liquefactive Necrosis

Question 11

This is a combination of coagulative and liquefactive necrosis encountered principally in the center of tuberculous infections.
Characteristic appearance is that of a soft, friable, whitish-gray debris resembling clumped cheesy material.
On microscopic examination, the necrotic focus appears as a collection of fragmented or lysed cells.
With amorphous granular pink appearance
Tissue architecture is completely obliterated.
often enclosed within an inflammatory border granulomas

example: lungs

Answer 11

Caseous Necrosis

Question 12

due to the action of lipases on triglycerides resulting to saponification.
The released fatty acids combine with calcium to produce the visible chalky white areas.
occurs in the female breast, mesenteries and in the omentum.
There is no enzymatic lipolysis but there is apparent rupture of the cell membrane with release of neutral fat. Subsequent phagocytosis of the fat follows.
example: acute pancreatitis

Answer 12

Enzymatic and Traumatic Fat Necrosis

Question 13

If produced by ischemia with a superimposed saprophytic bacterial infections

Answer 13

wet gangrene

Question 14

When bacterial infection does not supervene

Answer 14

Dry gangrene or mummification

Question 15

may be cause by: arteriosclerosis, Buerger’s disease, Raynaud’s disease, Ergot poisoning (ABRE)

Answer 15

Dry gangrene

Question 16

Marked by deposition of fibrin-like proteinaceous material in arterial walls
smudgy and eosinophilic on light microscopy
e.g. immune vaculitis, malignant hypertension

Answer 16

fibrinoid necrosis

Question 17

cell injury causes (OTGAIIN)

Answer 17

O2 deprivation 
Trauma (physical, chemical, radiation)
Genetics
Aging
Infectious agents
Immunologic reaction 
Nutritional Imbalance

Question 18

stress is present

Answer 18

irreversible

Question 19

stress is removed

Answer 19

reversible

Question 20

steps in paraffin preparation (OFDCECSO)

Answer 20

Obtain fresh specimen 
Fixation 
Dehydration 
Cleansing 
Embedding 
Cutting 
Staining 
Observe under microscope

Question 21

fat necrosis appears as yellowish-white and firm deposits. Formation of calcium soaps imparts the necrosed foci firmer and chalky white appearance

Answer 21

Grossly

Question 22

necrosed fat cells have cloudy appearance ; surrounded by inflammatory reaction

Answer 22

microscopically

Question 23

“falling off”, fragments of apoptotic cells break off

A pathway of cell death in which cells activate enzymes that degrade the cells’ own nuclear DNA and nuclear and cytoplasmic proteins.

Answer 23

Apoptosis

Question 24

Replacement of worn out cells.
Highly proliferative and hormone responsive tissues undergo cycles of proliferation and cell loss.
In immunity, elimination of excess leukocytes left at the end of an immune response.

Answer 24

Physiologic Apoptosis (causes)

Question 25

When DNA is severely damaged.
Accumulation of misfolded proteins
Some viruses induce apoptotic death of infected cells

Answer 25

Pathologic Apoptosis (causes)