1. Cell Injury Flashcards
Define anaemic
Decreased ability for Hb to carry O2
Define hypoxaemic
Arteriole O2 content is low
Define ischaemic
Interruption to blood supply
Define Histiocytic
Inability for cells to use oxygen due to disabled oxidative phosphorylation enzymes
Name 5 types of physical agents that can cause cell damage
Direct trauma Extreme temperature Changes in pressure Electrical currents Radiation
What are 2 features of reversible hypoxic injury?
Clumping of chromatin
Blebs
Swelling
Ribosome separation
Name the four classes of enzymes that Ca2+ activates in irreversible hypoxic injury
ATPase
Phospholipase
Protease
Endonuclease
Define the point of irreversible hypoxic injury
The point where membrane integrity falls leading to a massive influx of Ca2+
Describe the features of irreversible hypoxic injury
Further swelling Nuclear changes Rupture of lysosomes Membrane defects Myelin figures Lysis of ER Amorphous densities in mitochondria
Name the 3 nuclear changes
Pyknosis
Karyolysis
Karyohexis
Give 3 reasons why ischaemic tissue repurfusion can cause injury
Increase in oxygen free radicals
Increase in the number of neutrophils leading to inflammation
Complement proteins leading to the complement pathway
What molecules in cells do free radicals damage?
Lipids in cell membranes
Proteins
Carbohydrates
Nucleic acids
Name 3 free radical molecules
H2O2
O2-
OH▪️ (That’s a dot)
What are the names of 3 enzymes in the anti oxidant system?
Superoxide dismutase
Catalases
Peroxidases
Name 4 free radical scavengers
Vitamins A, C and E
Glutathione
What are heat shock proteins and give an example of one?
These recognise incorrectly folded proteins and repair them
Increase in production in response to heat increase
Ubiquitin is an example of these
Define oncosis
Swelling of a cell prior to death
Define apoptosis
Programmed cell death with shrinkage
Define necrosis
The morphological changes that occur in a living organism after a cell has been dead for some time
Give a visible feature of coagulative necrosis
Ghost outline
In coagulative necrosis is the process of denaturation greater or the activity of proteases?
Process of denaturation is greater hence a solid structure is left intact
Name an organ in which liquifactive necrosis can occur
Brain
Lungs
In liquifactive necrosis which has greater activity, the process of enzyme degradation or the process of denaturation?
The process of enzyme degradation
Which type of inflammatory cell is known to be able to cause liquifactive necrosis?
Neutrophils as they produce proteases
What is a cause of caseous necrosis?
TB
What is used to detect fat necrosis?
X Ray
Naked eye
Define gangrene
Term used to describe tissue that is visibly undergoing necrosis
What are the three types of gangrene?
Dry
Wet
Gas
What is dry gangrene?
Where the necrotic tissue is exposed to air, coagulative
What is wet gangrene?
Where the necrotic tissue is infected with bacteria making it liquifactive
What is gas gangrene?
Where the necrotic tissue is infected with anaerobic bacteria which produce visible, palpable bubbles of gas
What causes a white infarct?
Occlusion of an end artery
What causes a red infarct?
Extensive haemorrhage into dead tissue
In what organs can white infarcts occur in?
Heart
Kidneys
Spleen
What causes Rhabdomyolysis?
Myoglobin being released from dead muscle
What can Rhabdomyolysis cause?
Blocking of renal tubules leading to renal failure
What happens to cell size in oncosis?
Swells
What happens to the nucleus in apoptosis?
Fragmentation into nucleosomes
What happens to the cell membrane in apoptosis?
Remains intact but with an altered structure
What happens to the plasma membrane in oncosis/necrosis?
Disrupted, lysis
What happens to the cell contents in apoptosis?
Remain intact, can be released in bodies
What does a cell do with something it cannot metabolise?
Accumulates in the cell
What is the accumulation of Triacylglycerides often seen in the liver called?
Steatosis
What happens when phospholipids from disrupted cell membranes accumulate in the cell?
Form myelin figures
Name two diseases in which proteins accumulate in the cytoplasm of a cell
Mallary’s hyaline - damaged protein seen in hepatocytes in alcoholic liver disease
Alpha 1 antritrypsin deficiency - the incorrectly folded version produced by the liver stays in the ER - leas to emphysema
What are the names of 4 exogenous pigments?
Coal
Carbon
Soot
Tattoos
Name 3 endogenous pigments
Lipofuscin
Haemosiderin
Bilirubin
What is lipofuscin?
Brown/yellow old age pigment - is a sign of free radicals
What is haemosiderin?
Iron storage molecule
Shows iron overload in bruises
What is systemic overload of haemosiderin called?
Haemosiderosis
What shortens every time a cell divides?
Telomeres
What 3 types of cells contain telomerase allowing cells to maintain the original length of telomeres?
Germ cells
Stem cells
Cancer cells
What can fatty liver commonly be caused by?
🍺🍸🍾🍺🍸🍾
What can fatty liver lead to?
Steatosis and hepatomegaly
What symptoms may someone with fatty liver experience?
No symptoms
Is fatty liver reversible?
Yes
Acute alcoholic hepatitis involves what damage?
Hepatocytes necrosis
Formation of Malory bodies
Neutrophil infiltrate
Is acute alcoholic hepatitis reversible?
Usually
What are the features of a liver in cirrhosis?
Hard
Shrunken
Micronodules
Is cirrhosis reversible?
No, can be fatal
