Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pathology > 2.1 Necrosis > Flashcards

2.1 Necrosis Flashcards

1
Q

Necrosis is?

A

necrosis is the death of cells within the living body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Cellular events in necrosis:

A
  • Pyknosis
  • karyorrhexis
  • karyolysis​
  • cytoplasm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

pyknosis:

A

normal nuclear structure is replaced by a very dense, heavily staining, smaller angular mass of chromatin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

karyorrhexis:

A

nucleus has broken up into several dense pieces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

karyon =

A

nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

rhexis =

A

breaking up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

karyolysis:

A

nuclear staining with haematoxylin becomes faint and only the ghost outline​ of the nucleus remains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

cytoplasm sometimes stains?

A

brighter pink ( more eosinophilic​)
- pH drops and becomes more acidoc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe whats ​happening in pyknosis:

A
  • clumping of chromatin
  • general swelling of cell / ER due to water

Has a smaller nucleus and no nucleolus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe what’s​ happening in karyolysis:

A
  • dissolution of nuclear structure
  • rupture of cell membrane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Pyknosis: Which one is normal and infected? How can you tell?

A

A: infected: surrounded by darker pink cytoplasm
B: normal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Karyorrhexis: What are these cells? How can you tell?

A

Necrotic cells: dark blue/ black = fragmented nucleus material

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

3 main causes of necrosis?

A
  1. loss of blood supply - tissues need blood to supply to remain alive
  2. living agents - bacteria, virus, fungi, parasites
  3. Non-living​ agents - chemicals or physical injuries
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

loss of blood supply causes:

A
  • hypoxia
  • ischemia
  • infarction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

hypoxia:

A

reduced oxygen supply

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

ischemia​:

A

loss of blood supply
- complete loss

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

infarction:

A

sudden loss of blood supply to a portion of a tissue or organ

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

The consequences​​ of ischaemia depend on:

A
  • Type of cell: essential functioning cells (parenchyma) much more susceptible than the connective tissue supportive cells (stroma)
  • the metabolic activity of the tissue: very active organs are more susceptible ex: heart, liver, lungs
  • whether or not there is a good or potential collateral blood supply ex: kidney​ (important) vs lung not much difference
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Tissue ischemia​ occurs in 3 different ways:

A
  1. compression of the blood vessels from outside
  2. narrowing of the vessel lumen due to mural (wall) thickening
  3. blockage of the vessel lumen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

ischemia in tissues: intestinal torsion - compression of the blood vessels

A
  • venous outflow impeded
  • organ swells due to congestion
  • swelling impedes the arterial flow and arterial flow stops
  • tissue undergoes ischaemic necrosis
  • intestinal blood barrier compromised​
  • bacterial toxins absorbed - death or intestine friable: prone to rupture with peritonitis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

ischemia in tissues: narrowing of the vessel lumen - Arteriosclerosis

A
  • may occur in hypertension
  • rare in animals ( occasionally dogs with hypothyroidism or diabetes)
  • arteries harden
22
Q

ischemia in tissues: blockage of the lumen

A
  • important in animals: thrombosis and embolism
23
Q

Physical agents causing necrosis:

A
  • burns
  • cold/frostbite
  • x-rays
  • pressure
  • pinching or crushing tissue
24
Q

chemical agents causing necrosis:

A

directly caustic or corrosive in action or exert their effect when absorbed​ and metabolized to a more toxic substance

25
Q

Living agents that cause​ necrosis: Black disease

A

infectious necrotic hepatitis - clostridium novyi type B spores germinate in anaerobic environment created by the ​migration of liver fluke

26
Q

Black disease histology: 3 zones

A
  • Normal liver
  • Zone of inflammation (arrows)
  • central​ zone of necrosis
27
Q

Gross and histological features of necrotic tissues:

A
  • color change: dead tissues tend to be paler due to loss of circulation
  • consistency (texture): will vary according to the type of agent responsible, the tissue in which it is acting

**appearance may give clue to agent responsible, and type of necrosis based on their gross appeaernce

28
Q

What are the 3 main gross types/descriptions

A
  1. coagulative necrosis - remains firm
  2. liquefactive necrosis - becomes liquid
  3. caseous necrosis - looks like cottage cheese

Others
- fat necrosis - hard soap like appearance of affected body fat
- Gangrene - mostly a post -necrotic changhe

29
Q

What necrosis gross appearnace​ is this?

A

Coagulative: firmer and drier on the cut surface but will still resemble​ in outline the adjacent viable tissue

30
Q

Describe coagulative microscopic necrosis:

A
  • architecture of the tissue is preserved
  • cells may appear somewhat larger and their outline may be lost
  • cytoplasm appears structureless and homogenous
  • important nuclear changes
31
Q

What causes coagulative necrosis?

A

bacteria which produce toxins (clostridiuam spp) infarction, and some foci of viral replication ex: herpes virus

32
Q

2 types of liquefactive necrosis:

A
  1. malacia - CNS
  2. abscesses - anywhere in the
33
Q

liquefactive necrosis: abscesses

A
  • pyogenis (pus producing)
  • bacteria causes necrosis and attract vast numbers of neutrophils which they alos kill
34
Q

dying neutrophils release?

A

proteolytic enzymes - which digest necrotic tissue
- kill further tissue cells
- kill other incoming neutrophils

35
Q

Pus =

A

dead dying neutrophils, dead tissues and organisms

36
Q

Caseous necrosis gross appearance:

A
  • cheese like necrosis
  • white to yellowish color
  • dry and crumbling to cottage cheese

** really a mix of coagulation and liquefactive necrosis

37
Q

Caseous is caused by?

A

specific organisms ex: mycobacteria

38
Q

Caseous necrosis: mycobacteria tuberculosis

A
  • Microscopic: complete loss of architecture
  • purplish necrotic material due to nuclear and cytoplasmic components that stain with H&E
  • large portion composed of macrophages
39
Q

Mycobacteria have a high?

A

high lipid cell wall which resists digestion and allows replication​ within macrophage and evasion of phagolysis

  • organisms burst the macrophage and engulf by other macrophages
40
Q

Sequelae to necrosis:

A
  • surface necrosis can be shed
    basement membrane intact: epithelium regenerates = erosion
  • basement membrane breached, host inflammatory response​ –> tissue repair by fibrosis = ulceration
41
Q

small foci replaced by fibrous tissue =

A

scarring

42
Q

larger foci are replaced by fibrous tissue =

A

sequestrum

43
Q

Fat necrosis: gross appearance​

A
  • areas of focal opacity
  • very hard consistancy
44
Q

Fat necrosis: enzymatic

A

release of pancreatic enzymes lipase from a damaged pancreas into the adjacent mesenteric fat ex: pancreatitis

45
Q

fat necrosis: traumatic

A

In subcutaneous tissue following trauma to the area
- common in brisket of animals due to prolonged pressure

46
Q

Fat necrosis: diet related

A

rarley in cats associated with diets lacking antioxidants ex: vitamin E

47
Q

Gangrene:

A

post-necrotic change (ex: putrefaction of tissues

48
Q

wet gangrene:

A

primary: agent which initially kills the tissue, further putrefies

secondary: dead tissue being invaded by organisms which putrefy​ it

49
Q

dry gangrene

A

type of mummification
- occurs on the extremities
- air passing over the extremity removes the fluid content of the dead tissue
- appears lethery

50
Q

Can be a feature of granulomatous disease

A

Caseous necrosis: It is a prominent feature of granulomatous tuberculosis in cattle, the necrosis being composed of dead macrophages and organisms

Pathology (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions