A.pathology Exam-unit 1+2+3

Question 1

What is disease?

Answer 1

Not just illness or sickness, but alterations of normal form and function.
Clinically apparent or not

Question 2

What is pathogenesis?

Answer 2

The development of a disease from initiation to cellular and molecular manifestations

Question 3

When does cell injury occur?

Answer 3

When a cell no longer can maintain a steady state

Question 4

When does cell death occur?

Answer 4

If cellinjury is excessive, beyond the point of no return

Question 5

What is autolysis?

Answer 5

• post mortem
• self-digestion/degradation of cells and tissues by hydrolytic enzymes
• autolysis combined with putrefaction (bacterial breakdown of tissues)

Question 6

What is the histomorphology of acute cell swelling?

Answer 6

Tremendous swelling of all mitochondria+ER

• clumped chromatin
• folded nuclear membrane
• pale+structureless cytoplasm
• poorly visualized organelles

Question 7

What is pyknosis?

Answer 7

Shrunken, dark, homogenous and round nucleus

Question 8

What is karyorrhexis?

Answer 8

Nucleus ruptures and dark nuclear fragments released into cytoplasm

Question 9

What is karyolysis?

Answer 9

Extremely pale nucleus due to dissolution of chromatin, mainly by RNAase and DNAase action

Question 10

What does absence of nucleus mean?

Answer 10

A later stage of karyolysis where nucleus has been completely dissolved or lysed

Question 11

What is coagulation necrosis?

Answer 11

-preservation of outline of necrotic cells
- homogenous and eosinophilia cytoplasm due to protein coagulation
- pyknotic, karryohectic, karyolytic or absent nucleus
After lysis necrotic tissue will be phagocytosed

Question 12

What is coagulation necrosis?

Answer 12

Mainly seen in kidney, liver, muscles but never in brain parenchyma
-due to hypoxia or ischemia, can be caused by toxins

Question 13

What is caseation/caseous necrosis?

Answer 13

Conversion of dead cells into granular friable mass (cottage cheese appearance)
-coagulase of nuclear, cytoplasmic debris, mainly leukocytes
-older/chronic lesions
-all types of tissues
-surrounded by granulomatous inflammatory cells and fibrous CT capsule
Disrupted cell walls and tissue architecture is lost, mineralization is common
Classic cause is tuberculosis/paratuberculosis

Question 14

What is liquefactive necrosis?

Answer 14

Mainly in the CNS

- due to hypoxic death of cells resulting in rapid enzymatic dissolution

Question 15

What is gangrenous necrosis?

Answer 15

The continuation of coagulation necrosis

Three types

Question 16

What is moist gangrene?

Answer 16

Area of necrotic tissue further degraded by liquefactive action of saphrophytic bacteria from local environment that usually cause putrefaction
Causes:
-infarction of an extremity or intestine
-aspirated irritant agent in lungs
Grossly:
-soft, moist reddish to black tissues
- If bacteria produce gas, gas bubbles and putrid odor from hydrogen sulfide and marcaptans May occur
May eventually be separated from the normal tissue and slough

Question 17

What is dry gangrene?

Answer 17

-coagulation necrosis following infarction, results in mummification
- in lower part of extremity, tail, ears, udder
-could be due to ingested toxins or frostbite
-no proliferation of bacteria
-Grossly:
Shriveled, dry and brown to black tissue

Question 18

What is gas gangrene?

Answer 18

-anaerobic bacteria proliferating and producing toxins (c.perfringens, C.septicum)
- in penetrating wounds, which is anaerobic (clostridium)
Grossly:
-dark red to black with gas bubbles and fluid exudate (May contain blood)
Microscopically:
-coagulation necrosis of muscle, serohemorrhagic exudate, gas bubbles

Question 19

What is fat necrosis?

Answer 19

Three types
-enzymatic/pancreatic fat necrosis
- traumatic fat necrosis
-fat necrosis of abdominal fat in cattle
Microscopically:
Necrotic fat remains after solvents used in histologic preparations, when sapofication of fat necrotic adipocytes become basophilic

Question 20

What is enzymatic/pancreatic fat necrosis?

Answer 20

Destruction of fat in abdominal cavity, adjacent to pancreas

- due to activated pancreatic lipases in pancreatic fluid escaped from duct system

Question 21

What is traumatic fat necrosis?

Answer 21

When adipose tissue is crushed.

-in fat adjacent to pelvic canal, subcutaneous tissue or in fat over sternumof recumbent cattle

Question 22

What is fat necrosis of abdominal fat in cattle?

Answer 22

Large masses of necrotic fat in mesentery, omentum, retroperitoneally