Cell Injury

Question 1

define lethal cell injury

Answer 1

produces death

Question 2

define sublethal cell injury

Answer 2

produces injury not amounting to cell death, may be reversible or progress to cell death

Question 3

list the causes of cell death

Answer 3

oxygen deprivation, chemical agents, infectious agents, immunological reactions, genetic defects, nutritional imbalance, physical agent, ageing

Question 4

give an example of oxygen deprivation

Answer 4

heart attack

Question 5

what does cellular response to an injury depend on?

Answer 5

injury type, duration, severity

Question 6

what IC system are vulnerable?

Answer 6

cell membrane integrity, ATP generation, protein synthesis, genetic apparatus integrity

Question 7

define atrophy and give an example

Answer 7

shrinkage in cell or organ size by loss of substance

dementia

Question 8

define hypertrophy and give an example

Answer 8

increase in cell or organ size (pathological or physiological)

e. g. uterus hypertrophy in pregnancy
e. g. heart hypertrophy due to valve stenosis

Question 9

what causes hypertrophy?

Answer 9

increased function demand or hormonal stimulation

Question 10

define hyperplasia and give an example

Answer 10

increased cell number (pathological or physiological)

e. g. proliferative endometrium
e. g. carcinoma

Question 11

what causes hyperplasia?

Answer 11

pathological - XS hormonal or growth factor

physiological - hormonal or compensatory

Question 12

define metaplasia

Answer 12

reversible change in one adult cell is replaced by another (pathological or physiological)

Question 13

give a physiological example of metaplasia

Answer 13

cervix

• columnar epithelium line internal, stratified squamous line exterior
• puberty/pregancy cervix expands so columnar exposed to acid pH of vagina and become stratified squamous

Question 14

give a pathological example of metaplasia

Answer 14

barrett’s oesophagus

-startified squamous to columnar due to acid reflux

Question 15

define dysplasia and give example

Answer 15

precancerous cells which show genetic and cytological features or malignancy but not including underlying tissue
e.g. associated with barrett’s oesophagus

Question 16

what do cells undergoing dysplasia show?

Answer 16

big nuclei and more mitoses

Question 17

what changes are associated with reversible injury? give an example of each

Answer 17

fatty change - alcoholic fatty change

cellular swelling - ballooning degeneration (cells larger, membrane damaged, fluid leaks in)

Question 18

define necrosis

Answer 18

confluent cell death associated with inflammation

Question 19

name and describe the types of necrosis, give an example of each

Answer 19

coagulative - dead but look same as living e.g. MI
liquefactive - in brain e.g. cerebral infarct
caseous - cheese like appearance e.g. pulmonary TB
fat - damage to fatty tissue e.g. acute pancreatitis - lipase release breaks down TAG, FA bind with Ca2+ in EC fluid and Ca fat salts deposit

Question 20

define apoptosis

Answer 20

programmed cell death, signal cell with no inflammation

Question 21

how are apoptosed cells digested?

Answer 21

phagocytes

Question 22

list causes of apoptosis

Answer 22

embryogenesis, deletion of auto reactive T cell in thymus, hormone dependent physiological involution, cell deletion in proliferating population, DNA damage irreparable

Question 23

compare apoptosis and necrosis

Answer 23

apoptosis 
-physiological or pathological
-active energy dependent 
no inflammation
necrosis
-pathological
-when ATP runs out
inflammation

Question 24

define necropotosis and give characteristics

Answer 24

programmed cell death with inflammation

energy dependent, caused by viral infection, pathological