LEC CELLULAR INJURY AND CELL DEATH Flashcards
Results when cells are stressed so severely that they are no longer able to adapt, exposure to inherently damaging agents os suffer from intrinsic abnormalities
CELLULAR INJURY
CAUSES OF CELLULAR INJURY
Oxygen Deprivation-hypoxia
Physical Agents-accidents, temperature, Radiation
Chemical Agents and Drugs- Glucose, Salts, Arsenic, Cyanides, Carbon monoxide, Asbestos, Alcohol
Infectious Agents- Microorganisms
Immunologic Reactions- Self antigens
Genetic Abnormalities-deficiency in protein function
Nutritional imbalances-deficiency and diet as factors
Hallmarks of reversible cell injury
Reduced oxidative phosphorylation that results to ATP depletion
Cellular swelling caused by changes in ion conc and water influx
It is an event of a biological cell seizing to carry out its function
Cell Death
Reversible injury is described by:
Swelling/Hydrophic change/Vacuolar degeneration
Blebbing
Detachment of ribosomes
Clumping of nuclear chromatin
Earliest manifestation of all forms of cellular injury
Celllar swelling/Hydropic change/Vacuolar degeneration
Manifested by the appearance of lipid vacuoles in the cytoplasm
Fatty Change
Fatty change is often seen in what type of cells?
Hepatocytes and Myocardial cells due to its dependence on fat metabolism
Fatty change in a reversible injury happens due to
Hypoxic injury
Toxic or Metabolic Injury
What are the two types of cell death?
Apoptosis and Necrosis
It is called programmed cell death and is generally triggered by normal and healthy process in the body, which also occur as a defense mechanism during healing process and it beneficial to the body.
APOPTOSIS
A type of cell death which is commonly triggered by external factors such as trauma or infection. It is abnormal, harmful and often called as unprogrammed cell death.
NECROSIS
CELL SIZE IN APOPTOSIS AND NECROSIS
Apoptosis- shrinkage
Necrosis- enlarged
NUCLEUS IN APOPTOSIS AND NECROSIS
Apoptosis- Fragmentation into nucleosome
Necrosis- Pyknosis/Karyorrhexis/Karyolysis
PLASMA MEMBRANE OF APOPTOSIS VS NECROSIS
Apoptosis- intact, altered structure
Necrosis- disrupted
CELLULAR CONTENTS OF APOPTOSIS VS NECROSIS
Apoptosis- intact, maybe released in apoptotic bodies
Necrosis- enzymatic digestion, may leak out of cell
ADJACENT INFLAMMATION APOPTOSIS VS NECROSIS
Apoptosis- None
Necrosis- Adjacent
PHYSIOLOGIC AND PATHOGENIC ROLE APOPTOSIS VS NECROSIS
Apoptosis- often physiologic and may be pathological especially DNA damage
Necrosis- invariably pathologic
A type of necrosis which the architecture of the tissue is preserved, denatures not only the proteins but also the enzymes. This necrosis is often seen in a heart after an infarction, as well as the kidneys and adrenal glands.
COAGULATIVE NECROSIS
Transformation of tissues into a viscous fluid, seen in focal bacteria or fungal infections, leukocytes accumulation and liberation of enzymes. It also appears as creamy yellow due to pus. One of the example is hypoxic death within the CNS.
LIQUEFACTIVE/LIQUIFACTION NECROSIS
This type of necrosis refers to massive death of the tissue caused by a combination of ischemia and superimposed by bacterial infection.
GANGRENOUS NECROSIS
2 types of Gangrene
Coagulative- arterial occlusion “Dry Gangrene”
Liquefactive- venous occlusion “Wet Gangrene”
This type of necrosis is a conversion of destroyed cells into granular, friable mass made up of a mixture of coagulated protein and fats. It also means cheese like, the cells which are usually fragmented and lysed are enclosed in inflammatory border called granuloma. Usually seen in patient with tuberculosis.
CASEOUS NECROSIS
A type of necrosis that destructs the focal area of fat, release of pancreatic lipase into the peritoneal and pancreas. Often occurs in the calamitous abdominal emergency.
FAT NECROSIS
Other term for Acute Pancreatitis
Calamitous Abdominal Emergency
Fiber is the main reason for this type of necrosis to happen, shapes of tissues gets irregular and causes cell death. A bright pink and amorphous appearance is observed upon staining of H&R stains.
FIBRINOID NECROSIS
A type of necrosis which usually happens when the blood supply to the bone is absent. It is also known as osteonecrosis.
AVASCULAR NECROSIS
