cell injury and cell death

Question 1

what happens in left ventricular hypertrophy?

Answer 1

muscle of ventricle thickens

Question 2

what is necrosis?

Answer 2

when there is irreversible cell death - long term cell injury and therefore cannot be repaired

Question 3

what is oncosis?

Answer 3

oncosis is the pre lethal changes to cells that precede death

Question 4

what are some cellular adaptions?

Answer 4

atrophy and hypertrophy

Question 5

what happens in necrosis?

Answer 5

there is severe cell swelling and rupture

Question 6

what is apoptosis?

Answer 6

it is internally controlled cell death

Question 7

why does CO reduce oxygen transport?

Answer 7

it binds to Hb preferentially as it has a higher affinity for Hb than oxygen does - hypoxia

Question 8

what can cause cell death?

Answer 8

CO, physical agents - trauma, radiation, temp, chemical agents - drugs, immunological reaction, infectious agent, genetic derangement and nutritional imbalances

Question 9

what is the mode of action for trauma, acid, paracetamol OD, bacteria and radiation?

Answer 9

mechanical disruption of tissue 
coagulates tissue proteins 
metabolites will bind to liver cell proteins and lipoproteins 
toxins and enzymes 
damage to DNA

Question 10

why does ATP depletion result in death?

Answer 10

there is not enough energy for the cell so the tissue dies , loss of intercellular calcium hemostasis, oxygen and oxygen free radicals, defects in membrane permeability and irreversible mitochondrial damage

Question 11

`what are the three types of cell injury?

Answer 11

reversible, irreversible or ischaemia/reperfusion

Question 12

what is the basis of reperfusion?

Answer 12

damage on reperfusion mediated by oxygen free radicals

Question 13

what is reversible?

Answer 13

pallor, hydropic change, vacuolar degeneration and cell swelling

Question 14

what is irreversible?

Answer 14

lysosome or mitochondrial swelling, leakage of enzymes or damage to membrane

Question 15

what happens if damage is left too long?

Answer 15

reversible goes to irreversible

Question 16

how is a cascade of damage caused?

Answer 16

sever mitochondrial injury

Question 17

what is characteristic of reversible?

Answer 17

decrease in generation of ATP, loss of cell membrane integrity and defects in protein synthesis, and DNA damage

Question 18

what does persistent and excessive injury lead to and what are the characteristics of this?

Answer 18

irreversible damage
severe mitochondrial damage
extensive damage to plasma membranes
lysosome swelling

Question 19

what happens in irreversible damage?

Answer 19

there is leakage of membranes, therefore leakage of enzymes leading to apoptosis

Question 20

what are three types of cell death?

Answer 20

necrosis, oncosis and apoptosis

Question 21

what are some examples of programmed cell death?

Answer 21

menstruation and losing webbed digits - individual cell deletion in physiological growth control and in disease

Question 22

how does atrophy result?

Answer 22

increased apoptosis in excessive cell loss

Question 23

what are the characteristics of atrophy?

Answer 23

cell shrinkage, DNA fragmentation, formation of apoptotic bodies

Question 24

how does reversible cell injury result in cell swelling?

Answer 24

decrease in ATP production, decrease in acitivity of Na/K pump, increased sodium in the cell, osmosis and water movement into the cell

Question 25

how does enzymatic degradation and apoptosis occur in irreversible cell damage?

Answer 25

there is damage to the lysosome, mitochondrial and plasma membrane resulting in lysosome enzyme release into cytosol, Calcium into the cell and Cyt C leakage. Ca activated proteases and other enzymes and with lysozymes this results in enzymatic degradation. Cyt C and Calcium activate caspaces resulting in apoptosis

Question 26

what is necrosis?

Answer 26

cell death that results from failure in bioenergy and loss of plasma membrane integrity - includes inflammation and repair

Question 27

what are the differences between apotosis and necrosis?

Answer 27

size: A - cell shrinkage in one cell, N - cell swelling in many cells uptake: A - cell contents ingested by enighbouring cells with no inflammatory response, N - cell contents is ingested by macrophages and significant inflammation membrane: A - membrane blebbing but still integrity, apoptotic bodies form and N - loss of membrane integrity and cell lysis occurs organelles: A - mitochondria release pro-apoptotic proteins, chromatin condensation and non-random DNA degradation, N - organelle swelling and lysosomal leakage, random degradation of DNA

Question 28

does autophagy have an inflammatory response?

Answer 28

no - there is increased quantity of autophages formation - Atg proteins participation

Question 29

what can you see under microscope in necrosis?

Answer 29

disorganisation - inflammatory responses

Question 30

what types of necrosis are there?

Answer 30

fat, fibrinoid, coagulative, caseous, gangrenous or liquefactive

Question 31

what is an example of coagulative necrosis?

Answer 31

in MI

Question 32

what are the characteristics of coagulative necrosis?

Answer 32

it is the commonest form and happens in most cells, cells retain their outline and architecture is preserved but proteins coagulate, there is no proteolysis, and metabolic activity ceases. Proteins and enzymes are lost.

Question 33

what is liquefactive necrosis?

Answer 33

it is seen in the brain and is bacterial or fungal. It results in CNS hypoxia and is due to lack of substantial supporting stroma. It may result in neural tissue liquefying

Question 34

what is an example of gangrenous necrosis?

Answer 34

limb ischaemia

Question 35

what is gangrenous necrosis?

Answer 35

the types are wet, dry or gangrenous. The causes are infectious or bacterial. It is putrefaction of tissue and will appear black

Question 36

what can TB in lung cause?

Answer 36

it is the main cause of caseous necrosis and can cause military, cavitary or primary TB necrosis

Question 37

what is caseous TB?

Answer 37

it is structureless dead tissue that macrophages cannot digest

Question 38

how will caseous TB present in histology?

Answer 38

amorphous pink material in centre with necrotic debris and granulomas

Question 39

what are the causes of fat necrosis?

Answer 39

enzymes, trauma, panreatitis and excessive alcohol

Question 40

how will fat necrosis present?

Answer 40

loss of architecture, lots of vacuoles

Question 41

what 2 conditions is fibrinoid necrosis seen in and how does it present on histology?

Answer 41

malignant hypertension and autoimmune disease | wall of artery is bright pink with dark neutrophils

Question 42

what happens in mycocyte necrosis after an Mi?

Answer 42

enzymes are released - LDH, troponins and CK-MB - biomarkers for diagnosis

Question 43

what enzymes are released in pancreatic cell necrosis?

Answer 43

amylase

Question 44

where is troponin released from?

Answer 44

complex is released from actin filament

Question 45

how is apoptosis used in immune system?

Answer 45

death of post inflammatory neutrophils, virally infected cells and self reactive lymphocytes