Cell responses to injury

Question 1

what is adaptation?

Answer 1

• Reversible process which occurs when there is stress to a cell
• Can be physiological or pathological
• Once stimulus goes, it goes back to normal

Question 2

what happens if the cells have an inability to adapt during adaptation?

Answer 2

cell injury

Question 3

what are the 5 types of cellular adaptation?

Answer 3

• hypertrophy
• hyperplasia
• atrophy
• metaplasia
• dysplasia

Question 4

why does hypertrophy occur?

Answer 4

increase in protein synthesis, leading to increase organelle production and growth factor

Question 5

what is hypertrophy?

Answer 5

increase

Question 6

hyperplasia of the thyroid is related to what deficiency?

Answer 6

iodine deficiency

Question 7

what is atrophy

Answer 7

decrease in cell size

Question 8

what is metaplasia?

Answer 8

change of one cell type to another

Question 9

what is dysplasia?

Answer 9

abnormality in the formation of a tissue

Question 10

name some causes of cell injury?

Answer 10

• oxygen deprivation
• physical agents
• chemical agents and drugs
• infectious agents
• immunological reactions
• genetic abnormalities
• nutritional imbalances

Question 11

what is hypoxia?

Answer 11

oxygen deprivation

Question 12

hypoxia can happen due to what 3 points?

Answer 12

• reduced blood flow (ishemia)
• inadequate oxygenation of blood
• decreased oxygen carrying capacity

Question 13

what is a reperfusion injury?

Answer 13

restoration of blood flow after ischemia or lack of blood flow that leads to oxidative stress, inflammation, intracellular calcium overload, ROS

Question 14

what 2 ways can chemical agents injure a cell and explain?

Answer 14

• direct toxicity= goes straight to cell and injures it
• conversion of toxic metabolites= chemical enters body and is changed to metabolites that cause injury due to membrane damage and formation of ROS

Question 15

what are the 4 physical agents that can cause cell death?

Answer 15

• mechanical
• radiation
• extreme temperatures
• electric shock

Question 16

what’s infectious agents can cause cell injury/death?

Answer 16

• parasites
• prions
• viruses
• fungi
• bacteria

Question 17

what immunological reactions can cause cell injury/death?

Answer 17

• reactions to self-antigens = autoimmune disease
• external agents e.g allergies

Question 18

how can genetics lead to cell injury/death?

Answer 18

• deficient protein function
• misfolded proteins
• accumulation of damaged DNA

Question 19

how can nutritional imbalances cause cell injury/death?

Answer 19

• obesity
• under nutrition

Question 20

what does causes of cell injury depend on?

Answer 20

• nature of injury
• duration of injury
• severity of injury

Question 21

what are the 4 mechanisms of cell injury?

Answer 21

• mitochondria damage leading to ATP depletion
• cell membrane damage
• disruption of biochemical pathways
• DNA damage

Question 22

describe the mechanism of mitochondrial damage in relation to cell injury

Answer 22

• caused mainly by production of ROS (reactive oxygen species)
• formation of channels leads to release of CALCIUM into cytosol
• oxygen deprivation/ ATP depletion
• mutation of mitochondrial genes

Question 23

how can DNA be damaged

Answer 23

• radiation
• drugs
• ROS
• Aging
• Chemotherapeutics

Question 24

what is a reversible injury?

Answer 24

functional and structural alterations in mild forms of injury, these can resolve if the stimulus is removed

Question 25

Describe physical changes which comes with reversible cell injuries

Answer 25

• Pallor
• increased rugor
• increased weight