Cell responses to Injury I

Question 1

What can reversible cell injuries cause?

Answer 1

Pallor, Increased rugor, increased weight, generalised cell swelling and fatty changes

Question 2

What is cell adaptation?

Answer 2

A reversible process that occurs to a cell when stress is applied that allows the cell to survive in changes of phsyiologic state

Question 3

What is hypertrophy?

Answer 3

Increased cellular protein production that causes increased cell size and synthesis/ assembly of intracellular components and increased workload (due to increase in hormones)

Question 4

What is hyperplasia?

Answer 4

Increased number of cells (driven by growth factors) and increased output of new cells and increased functional capacity of hormone sensitive organs (e.g estrogen during pregnancy)

Question 5

What is atrophy?

Answer 5

a reduction in size and number of cells (driven by growth factors), decrease in protein synthesis and an increase in protein degredation

Question 6

What are some pathologic causes of atrophy?

Answer 6

decreased worload, loss of blood supply, inadequate nutrition, pressure, senile atrophy, denervation atrophy

Question 7

What are some physiologic causes of atrophy?

Answer 7

normal development

Question 8

What is metaplasia?

Answer 8

When a mature cell is replaced by a different cell type, e.g smokers can gain squamous epithelium instead of cilliated

Question 9

What is dysplasia?

Answer 9

an increase in the number of poorly differentiated cells (atypical) predisposes to neoplasia

Question 10

How does being senile cause atrophy?

Answer 10

reduces the capacity to gain muscle

Question 11

When does cell injury occur?

Answer 11

When a cell is unable to adapt

Question 12

What can cause cell injury?

Answer 12

oxygen deprivation, physical/chemical agents
infectious agents/ immunologic reactions

Question 13

What is Hypoxia?

Answer 13

oxygen deprivation, (reduction in aerobic respiration or reduction in blood flow ischaemia) inadequate oxygenation can be due to CO poisoning

Question 14

What is reperfusion injury?

Answer 14

Restoration of blood flow to previously ischaemic tissues

Question 15

What are the 3 different types of dysplasia?

Answer 15

Anisocytosis (change in nucleus), Poikilocytosis (change in cells), and Karyomegaly (nucleus becoming abnormally enlarged)

Question 16

What is reperfusion injury?

Answer 16

Blood flow in a tissue that was previously exposed to ischaemia means you get a lot of dead inflammatory cells that create a lot of ROS

Question 17

What are chemical agents?

Answer 17

directly toxic and can cause injury to the cell membrane, e.g a build up of mercury in tuna

Question 18

What are some examples of physical agents?

Answer 18

mechanical, extreme temperatures (e.g enzyme damage), radiation and electric shock

Question 19

What are some examples of infectious agents?

Answer 19

parasites, prions, viruses, bacteria and fungi

Question 20

What are some genetic issues that can effect cells?

Answer 20

deficient protein missfolding, deficient protein function and damaged DNA

Question 21

What is an example of an immunological reaction?

Answer 21

hayfever

Question 22

What is the effect of obesity and malnutrition?

Answer 22

Malnutrition can lead to over/under conditioning which then leads to a cell that cannot grow/thrive

there is also a predisposition to disease

Question 23

What is ROS?

Answer 23

an unstable molecule/ compind due to an electron in the outer shell- it is usually produced during normal respiration- if mitochondria is damaged it enters the cytosol and causes missfolding of proteins/ damages to DNA

Question 24

What causes mitochondrial damage (a mechanism of cell injury)

Answer 24

comes from injurious (severe/persistent stimuli) like ROS or mutation of mitochondrial genes

Question 25

What are the consequences of mitochondrial damage

Answer 25

ATP deletion, production of new channels or incomplete phosphorylation

Question 26

What does disruption of biochemical pathways cause?

Answer 26

oxidative stress, disturbances in calcium homeostasis and endoplasmic reticulum (causes a reduction in protein production)

Question 27

What does membrane damage cause?

Answer 27

causes ROS, decreased phospholipid synthesis and cytoskeleton abnormalities

Question 28

What can cause damage to DNA?

Answer 28

Radiation, Drugs, ROS, Aging and Chemotherapeutics

Question 29

Name 5 things that can cause free radicals to be generated

Answer 29

• Absorbance of radiant energy
• Activated leukocytes
• Enzymatic metabolism
• Transition metals
• Nitric oxide

Question 30

Name 3 things that can cause mitochondrial damage

Answer 30

• Low Oxygen supply
• Toxins
• Radiation

Question 31

Name three things that can disrupt biochemical pathways

Answer 31

• Calcium homeostasis
• Endoplasmic retciulum stress
• Oxidative stress

Question 32

Name 4 things that can cause membrane damage

Answer 32

1. ROS
2. Decreased phospholipid synthesis
3. Incresaed phospholipid breakdown
4. Cytoskeletal abnormalities

Question 33

Name 3 membranes that can be affected by membrane damage

Answer 33

• Mitochondrial membrane
• Plasma membrane
• injury to lysosomal membrane

Question 34

Name 5 things that can damage DNA

Answer 34

• Radiation
• Drugs
• ROS
• Aging
• Chemotherapeutics

Question 35

When is ROS created?

Answer 35

ROS is always created but damage to the mitochondria may mean that ROS cannot be eliminated