NECROSIS Flashcards
What is necrosis?
A condition of cell death through injury of diseases, especially in a localized area of the body
What happens to the cytoplasm during Necrosis?
Cytoplasm undergoes digestion by enzymes released from lysosomes and phagocytic cells.
What do lysosomes of necrotic cells release?
Lysosomal enzymes for this purpose only when the cell is lethally injured.
What does cell digestion promote?
Elimination of the necrotic cell and thus speeds up the healing process.
Necrosis simple definition:
When there is IRREVERSIBLE changes within the cell, and it dies.
What are the necrosis forms?
1) Coagulative
2) Liquefactive
3) Casseous
4) Gummatous
5) Zenker’s
6) Fat Necrosis (Steatonecrosis)
7) Fibrinoid
8) Gangrene
9) Apoptosis
What does Coagualative Necrosis imply?
It implies the preservation of basic outline of coagulated cells for a period of at least some days.
What do the cells look like in regard to Coagulative Necrosis ?
There is death of some cells but the tissue is strong enough to prevent the whole tissue to be affected.
What forms in Coagulative Necrosis?
SCAR TISSUE
What is Coagulative Necrosis characterized by?
1) Denaturation of cytoplasmic proteins
2) Breakdown of cell organelles
3) Cell swelling
What is an example of Coagulative Necrosis?
Myocardial Infarction
Explain why Myocardial Infarction would be an example of Coagulative Necrosis:
The left ventricle after an attack is strong enough to only do cell necrosis and keep the blood inside the heart preventing the persons death
What is Infarction?
It is a zone/portion of necrosis inside a tissue caused by oxygen deficiency
What are the 2 types of Infarction?
White and Red
What is “White Infarction?”
A characteristic of a single blood supply
What is “Red Infarction?”
It develops in the tissue because of dual blood supply
hemorrhagic lung
What happens during Liquefactive Necrosis?
There is complete digestion of the dead cells, resulting in transformation of the tissue into a liquid viscous mass
What is Liquefactive Necrosis characterized by?
1) Complete digestion of the dead cells
2) Transformation of the tissue into a liquid viscous mass
What would be an example of Liquefactive Necrosis?
Ischemic stroke to the brain
What happens during Ischemic stroke to the brain?
This form of Necrosis develops in the nervous tissue, especially in the brain, where there is little/no collagen fibers
What happens after ischemic stroke to the brain (Liquefactive Necrosis)?
WBC’s remove the debris and there are spaces left in the brain “Holes in the Brain”
Casseous Necrosis aka
Cheese Like
What are the 2 types of Casseous Necrosis?
1) Amorphous granular debris composed of Fragmented Coagulated cells
2) Amorphous granular debris enclosed within a distinctive inflammatory border known as Granulomatous Reaction
What is a granuloma?
A collection of immune cells that are trying to get rid of a foreign substance but are unable to eliminate forming this inflammatory response
What does Casseous Necrosis cause?
Caves and holes destroying vessels causing Profuse Respiratory Hemorrhages.
What does caseous Necrosis affect?
All but hair and Nails
What are examples of Casseous Necrosis?
Tuberculosis and Leprosy
Where does Gummatous Necrosis Develop?
Only in Syphillis aka Luis Disease
What is Gummatous Necrosis
This is death of the tissue caused by Treponema Pallidum and usually requires sexual transmission
What is aka of Syphilis?
Luis Disease
When is Syphillus not curable?
When it’s in the tertiary stage
What is Primary Syphillus?
Single Chancre (painless skin ulceration)
What is Secondary Syphillus?
Involves skin of the hand and feet
What is Tertiary Syphilis?
Involves gummas (type of granuloma), the CVS and NS
What are the symptoms associated with Tertiary syphilis?
Numbness and Paresthesia affecting the NS and CVS
If the spinal cord is affected in the (posterior column) in Tertiary Syphillis, what is it called?
It is called Tabes Dorsalis
What is the name of the gray matter atrophying in Tertiary Syphillis?
General Paresis aka General Paresis of Insane
What is Zenker’s Necrosis?
It is a severe glassy or waxy necrosis of skeletal muscles in acute infectious diseases
What is an example of Zenker’s Necrosis?
Typhoid/ Typhoid fever
What is Typhoid fever caused by?
Salmonella Bacteria
How does the Typhoid fever (Zenker’s Necrosis) occur?
Infection occurs by ingesting contaminated food or water. Prevented by washing hands
What is another way that Zenker’s Necrosis can occur?
Snake Bite causing Necrosis of the tissue
What is Fat Necrosis (Steatonecrosis)?
Necrosis of adipose tissue, characterized by formation of small quantities of calcium soaps, product of fat when is hydrolyzed into glycerol and fatty acids
What is an example of Pancreatic Necrosis aka Pancreonecrosis?
Gall bladder stones block the bile duct so pancreas secretions are also blocked leading to degradation of pancreas
What can happen during Pancreatic Necrosis (Fat Necrosis)?
It is a very common cause of death (within hours) in young people especially females
Where does Fibrinoid Necrosis occur?
In walls of blood vessels when endothelial and smooth muscle cells are injured and dying
When is Fibrinoid Necrosis usually developed?
In immunologically mediated disorders or immunopathologies
Active Immune System Participation
What is an example of Fibrinoid Necrosis?
Aschoff’s Nodes
What are Aschoff’s Nodes?
Neurotic Nodules located in heart as a cause of inflammation (strep infection)
Where would Aschoff’s Nodes be seen?
In individuals with Rheumatic Myocarditis
Histological findings of rheumatic myocarditis are Aschoff’s Nodes
Histological findings of Rheumatic Myocarditis are ______
Aschoff’s nodes
What is Gangrene Necrosis?
A serious and potentially life-threatening condition that arises when a considerable mass of body tissue dies
Gangrene is also known as _____
Gangrene of extremities and intestines (affect both)
What is Gangrene characterized by?
It is a form of coagulative necrosis characterized by presence of noxious products of anaerobic bacterial metabolism
What is Gangrene (Gangrenous Necrosis) associated with?
Infection, infection leads to gangrenous necrosis.
Lack of blood supply (could be a form of necrosis already existing)
What are the 3 types of Gangrene?
Dry, Wet, Gas
What is happening during Dry Gangrene?
Coagulation is sustained
What can be the 3 causes of “Dry Gangrene?”
Ischemia, Atherosclerosis , and Diabetes Mellitus
What is Ischemia?
Lack of blood supply to the organ or tissue
What disease would you see ischemia associated with Dry gangrene?
Distal parts of fingers in Systemic Sclerosis (aka scleroderma).
What is systemic sclerosis?
Over activity of the fibroblasts (make CT)
What is a symptom associated with systemic sclerotic tissue?
Claw hands
What is Atherosclerosis associated with?
Buerger’s Disease (aka thromboangitis obliterans)
Buerger’s Disease aka
Thromboangitis Obliterates
What does Buerger’s Disease affect?
Nerves and Veins, NOT arteries
What type of gangrene is due to smoking?
Atherosclerosis (Dry Gangrene)
- Necrosis must be removed so that no more tissue in extremities gets affected
What is the disease associated with Diabetes Mellitus (Dry Gangrene under 8 Gangrene )
Diabetic Microangiopathy
What is Diabetic Microangiopathy?
Obliteration of the distal small Vessels which results in gangrene of the fingers
What is Wet Gangrene?
It occurs if enzymes of invading phagocytic cells break down the necrotic debris and produce some liquefaction.
What will be seen with Wet Gangrene?
Swelling and Redness, with NO bone problems
What is a cause of Wet Gangrene?
Anaerobic bacteria (clostridium perfringens, bacillus fusiformis)
What 2 things are associated with Wet Gangrene?
1) Bed sores
2) Blockage of blood flow
What are bed sores? (wet gangrene)
Continuous pressure of the tissue against bed causes decreased blood flow to the areas
What is Blockage of Blood flow?(wet gangrene)
Wet gangrene in the distal parts of the fingers in polyarteritis nodosa
What is Polyarteritis Nodosa?
Distal Phalanxes are open to the air “Naked Bones”
What are the 2 examples of wet gangrene –> Blockage of blood flow?
Polyarteritis Nodosa and Intestinal Gangrene
What is Intestinal Gangrene due to?
Anaerobic Bacteria in wounds, obstruction of blood supply or abdominal herniation
What is Gas Gangrene?
A bacterial Infection that produces gas within tissues. Common in military
What are the 2 bacteria associated with Gas Gangrene?
Clostridium Perfringens and Anaerobic Streptoccocci
What is Apoptosis?
Greek for “Falling Off”
What is Apoptosis full definition?
A pathway of cell death that is induced by a tightly regulated intracellular program in which cells destined to die activate enzymes that degrade the cells own DNA and nuclear and Cytoplasmic proteins.
What are the 2 types of Apoptosis?
Physiological and Pathological
What is physiological Apoptosis?
“Normal conditions of apoptosis”
The programmed destruction of cells during embryogenesis
What 2 things would you see in Physiological Apoptosis?
Hormone dependent Evolution in the adult and cell death induced by cytotoxic T cells
What is Hormone dependent evolution in relation to Physiological Apoptosis?
Destruction of the gonads with age in males and menstruation in woman where endometrium aka decidual cells die
What is Pathological Apoptosis?
Cell injury in certain viral diseases, and death of neutrophils during an acute inflammation
What is Caspase?
Group of the cysteine containing proteolytic enzymes, which play essential roles in apoptosis (programmed cell death) necrosis and inflammation
