Cell Death (P) Flashcards
True or False
All cells in a multicellular organism undergo growth and death
True
What is the importance of cellular death?
It is essential for an organism to grow and survive
True or False
The human body is made up of innumerable types of cells in various parts of the body
True
What are the 2 processes of where cell death occur?
1) Necrosis
2) Apoptosis
What is necrosis?
It is the mechanism of cell death that occurs in living tissue
What is the result that is always present in pathological conditions?
Necrosis
What are the causes of necrosis?
1) Ischemia
2) Pathogens (bacteria, viruses, and fungi)
3) Toxins
4) Inflammation
What happens if necrosis is present in the human body?
1) The plasma membrane of cells gets disrupted
2) The cellular contents leak out
What are the actions of the human body if necrosis is present?
1) The body recognizes these elements as potential injurious agents
2) The body launches an acute inflammatory response at the site of necrosis
What is the importance of inflammatory response?
It is essential to lay foundation of healing process
What is the characteristic of necrosis?
These are cellular changes after cell death that do not become visible immediately
What is the time duration before necrosis become visible using electron microscope?
1 - 3 hrs
What is the time duration before necrosis become visible using light microscope?
4 - 6 hrs
What is the effect of necrosis?
Loss of plasma membrane integrity
What is the effect of loss of plasma membrane integrity?
Cardiac sp enzymes leak out
What is the process (or steps) present in necrosis?
1) Normal
2) Pyknosis
3) Karyorrhexis
4) Karyolysis
What is the characteristic of the cytoplasm of a necrotic cell?
It looks deeply acidophilic w/ H & E stain
What is the reason why the cytoplasm of a necrotic cell appear deeply acidophilic (if H & E stain is used)?
Due to the presence of protein denaturation & loss of ribosomes
Denatured proteins loves to bind w/ what?
Eosin
rRNA loves to bind w/ what?
Hematoxylin
What are the changes that happen to a necrotic cell?
1) It gets a homogenous appearance
2) It becomes vacuolated
3) The myelin figures accumulate within the cytoplasm
What is the event present in necrosis?
The cell either gets phagocytized / degrades into fatty acids
What is the product of the combination of fatty acids and calcium ion?
Calcium soaps
Fatty acids + calcium ion = calcium soaps
The necrotic cell becomes calcified by what?
EM
What are the 2 mechanisms of necrosis?
1) Autolysis
2) Heterolysis
What is the mechanism of action present in autolysis?
The necrotic cells are digested by their own enzymes
What are the characteristics of autolysis?
1) This is present rapidly in tissues w/ large amt of enzymes
2) This is present in intermediate tissues
3) This is present in delayed tissues
What are the exs of tissues w/ large amt of enzymes where autolysis is rapidly present?
1) Pancreas
2) Gastric mucosa
What are the exs of intermediate tissues where autolysis is present?
1) Heart
2) Kidney
3) Liver
What are the exs of delayed tissues where autolysis is present?
1) Fibrous tissues
2) Connective tissues
What is the mechanism present in heterolysis?
The digestive enzymes are secreted by other cells
What are the cells that secrete digestive enzymes in heterolysis?
1) Neutrophils
2) Macrophages
What are the 2 major types of tissue necrosis?
1) Coagulative necrosis
2) Liquefactive necrosis
What are the other types of tissue necrosis?
1) Caseous necrosis
2) Fat necrosis
3) Fibrinoid necrosis
4) Gangrene
What are the situations that are present in coagulative necrosis?
1) Digestion of necrotic cells by autolysis is inadequate
2) Proper digestion occurs by heterolysis
3) Dead cells retain their outline for several days
4) Organelles disappear slowly
5) Stages of nuclear digestion are usually observable
At what type of organs is coagulative necrosis commonly seen?
It is commonly seen in solid organs
What are the exs of solid organs where coagulative necrosis is commonly seen?
1) Heart
2) Kidney
3) Liver
4) Adrenals
What is the injurious agent for coagulative necrosis?
Hypoxia
What are the disorders / conditions where non-hypoxic coagulative necrosis present?
1) In cases of burns
2) Viral hepatitis
What are the macroscopic changes present in a tissue where coagulative necrosis is present?
1) In the initial several hrs, it appears normal
2) The area shows mottled pattern w/c resulted to the occurrence of blood seepage
3) Few days later, the necrotic area looks firm and pale-lined by hyperemia w/c results to acute inflammation
4) Hemorrhagic occurrences are present
Provide an ex of the site where necrosis is already present in congested tissues
Testes
At what tissues do hemorrhagic necrosis occur?
In tissues w/ dual blood supply
What is the action present in liquefactive necrosis?
The necrotic cells undergo complete digestion
Liquefactive necrosis gives rise to what?
It gives rise to a liquid-like material (liquefaction)
What are the sites where liquefactive necrosis is seen?
1) Pancreas
2) In cases of suppurative inflammation
What are present in liquefactive necrosis?
1) Removal of dead tissues via autolysis
2) Removal of dead tissues via heterolysis
What are the causes of liquefactive necrosis being seen in sites where suppurative inflammation is present
Pyogenic bacterial infections
Liquefactive necrosis usually occurs where?
Brain
What happens if liquefactive necrosis is present in the brain?
Formation of a pus-filled cyst
What are the characteristics of liquefactive necrosis macroscopically?
1) It becomes soft and pulp-like
2) Presence of pus occurs
What are the characteristics of the pus present (as macroscopic characteristic of liquefactive necrosis) in liquefactive necrosis?
1) It is creamy
2) It has a yellowish / greenish consistency in the center
3) It is surrounded by a pyogenic membrane
What is the microscopic characteristic of liquefactive necrosis?
The cellular outlines of dead cells cannot be identified in pus
What are present in the pus present microscopically in liquefactive necrosis?
Numerous neutrophils
What are the characteristics of caseous necrosis?
1) It is characterized by yellowish crumbling nature of dead tissue whereas it is cottage cheese in appearance
2) It has a caseous consistency
At what disorders / conditions is caseous necrosis present?
1) MTB infections
2) Fungal infections
What is the cause of occurrence of caseous necrosis?
It is present due to the delayed hypersensitivity rxn evoked by activated macrophages & epithelioid cells
What is the cause of the occurrence of caseous consistency present in caseous necrosis?
It is present due to the release of mycolic acid from damaged cell wall of the mycobacteria
Where does fat necrosis occur?
Adipose tissue
What are the types of fat necrosis?
1) Enzymatic fat necrosis
2) Traumatic fat necrosis
At what disorders / conditions is enzymatic fat necrosis present?
1) Acute pancreatitis
2) Other forms of pancreatic injuries
What are the fxns (or effects) of phospholipases w/c are part of enzymatic fat necrosis?
1) These damages cell membranes
2) These causes necrosis of adipocytes
3) These causes leakage of TAG
What is the fxn of lipases (w/c are a part of enzymatic fat necrosis) in enzymatic fat necrosis?
It breaks down TAG into free fatty acids
What is the result of the combination of free fatty acids and calcium ions?
Calcium salts
Free fatty acids + calcium ions = calcium salts
What is the characteristic of calcium salts (w/c are part of enzymatic fat necrosis) when these are deposited?
These appear as chalky white plaques
Where are calcium salts deposited?
At the site of necrosis in the peritoneal cavity
What is the other term of traumatic fat necrosis?
Non-enzymatic necrosis
Where is traumatic fat necrosis commonly present?
In tissues w/ high lipid content
What are the exs of tissues w/ high lipid content (where traumatic fat necrosis is commonly present)?
1) Breast
2) Subcutaneous tissue
What are the situations present in traumatic fat necrosis?
1) Adipocytes gets disrupted
2) Undigested TAG forms lipid pools
3) Chronic inflammation is present w/c is associated w/ collection of lipid laden macrophages
What is the cause of adipocytes being disrupted?
Trauma
What are the results of adipocytes being disrupted?
Releases TAG and lipase
When are undigested TAG w/c forms lipid pools present?
1) In cases of chronic inflammatory rxn
2) In cases of fibrous tissue formation
What is the term referred to chronic inflammation associated w/ collection of lipid laden macrophages?
Xanthogranulomatus inflammation
What is fibrinoid necrosis?
It is a special form of necrosis that is usually seen in immune rxns involving blood vessels
What are the situations present in fibrinoid necrosis?
1) Deposition of complexes of Ag and Abs
2) Presence of fibrin
What are Ags and Abs (in fibrinoid necrosis)?
Immune complexes
What happens to fibrin (w/c is a part of fibrinoid necrosis)?
It is leaked out from blood vessels
What is the characteristic of fibrinoid necrosis?
It appears as color bright pink w/ the use of H&E stain
What are the disorders / conditions where fibrinoid necrosis is present?
1) In cases of healing by fibrosis
2) Polyarteritis nodosa
3) Microscopic polyangitis
4) Wegener’s granulomatus
5) SLE
What is gangrene?
It is an area of dead tissue in a living person
What is the characteristic of gangrene?
It is characterized by black discoloration
What are the types of gangrene?
1) Wet gangrene
2) Dry gangrene
What are the characteristics of wet gangrene?
1) Bacterial infection is present in the affected tissue
2) It is swollen w/ blisters w/c is characterized by having oozing fluid
3) It is color red
4) It is warm
5) It has a foul odor
When do dry gangrene occur?
It occurs when blood supply is cut off
What are the characteristics of dry gangrene?
1) The area / site becomes dry
2) The site shrinks
3) The site turns black
What is apoptosis?
It is the mechanism by w/c cells die due to activation of an inbuilt program
Apoptosis is also referred to as what?
Programmed cell death
What is the characteristic of apoptosis?
It is the physiological mechanism of cell death
What are the situations present in apoptosis?
1) During embryogenesis, shaping of organs and body is present
2) Presence of hormone induced tissue involution, such as involution of mammary tissue after breast feeding and menopause
3) Getting rid of cells w/ genetic damage during cell division
4) Sloughing off of the uterine endometrium
5) Removal of unwanted autoreactive immune cells
What is the process (or steps) of apoptosis?
1) A normal cell is present
2) The cell shrinks and the chromatin condenses
3) The membrane starts blebbing and the organelles disintegrate
4) The nucleus and organelles collapse & the membrane continues to bleb
5) Formation of apoptotic bodies occur
6) No inflammation is present
What are the characteristics of the cell that are present in the case of apoptosis?
1) The cell membrane is intact
2) There is no leakage of cellular contents outside
3) There is no associated inflammation
What are the characteristics of apoptosis?
1) It is a silent process
2) It has minimal 2ndary consequences to the host
3) It is an energy dependent process
Answer the ff questions in connection to the given cell death process:
1) What is the etiology?
2) What is the cytology process present?
3) What happens in the cell membrane?
4) What happens to the nucleus?
5) What is/are the characteristic/s of the cytoplasm?
6) What happens to the organelles?
7) Is inflammatory rxn present?
8) What is/are the marker/s that can be used?
Given cell death process: Apoptosis
1) Physiologic or pathological
2) Cell shrinking
3) Formation of blebs are present (w/out significant inflammation)
4) The chromatin becomes condensed and fragmented; it appears as basophilic
5) It is deeply eosinophilic
6) They aggregate
7) Absent
8) DNA laddering
What are the components of DNA laddering?
180 base pairs and nitrogenous bases
Answer the ff questions in connection to the given cell death process:
1) What is the etiology?
2) What is the cytology process present?
3) What happens in the cell membrane?
4) What happens to the nucleus?
5) What is/are the characteristic/s of the cytoplasm?
6) What happens to the organelles?
7) Is inflammatory rxn present?
8) What is/are the marker/s that can be used?
Given cell death process: Necrosis
1) Always pathological (ex. ischemia)
2) Cell swelling
3) It disappears (w/ inflammation)
4) Pyknosis, karyorrhexis, and karyolysis occur
5) It has the presence of cytoplasmic granulation
6) These breakdown
7) Present
8) No official marker
