4

Question 1

What is regeneration?

Answer 1

Replacement of dead / damaged cells w differentiated cells

Question 2

What are labile cells? (+examples)

Answer 2

Cells which normal state is Active Cell Division (G1-M-G2)
Rapid prolif

E.g. epithelial / haematopoietic cells

Question 3

What are stable cells? (+examples)

Answer 3

Cells which normal state is Resting State (G0)
Variable regen speed

E.g. hepatocytes / osteoblasts / fibroblasts

Question 4

What are permanent cells? (+examples)

Answer 4

Cells which normal state is Resting State (G0)
Can’t divide (No regen)

E.g. Neurons / cardiac myocytes

Question 5

Define unipotent cells

Answer 5

Cells that prod only one type of differentiated cell

Question 6

Define multipotent cells

Answer 6

Cells that prod several types of differentiated cell

Question 7

Define totipotent cells

Answer 7

Cells that can prod any type of differentiated cell

Question 8

What are the 3 stages of Fibrous Repair?

Answer 8

1. Cell Migration
2. Angiogenesis
3. ECM

Question 9

What are the 3 types of cell involved in Cell Migration of fibrous repair?

Answer 9

1. Inflamm cells (MAC / Neut: phagocytosis) (MAC / Lymphocytes: Chem. mediators)
2. Endothelial cells (angiogenesis)
3. Fibroblasts / Myofibroblasts (make collagen for ECM) (wound contraction)

Question 10

What is the purpose of Angiogenesis in fibrous repair?

Answer 10

Delivers O2 and nutrients

Question 11

What are are the 7 steps of Angiogenesis in fibrous repair?

Answer 11

1. Endothelial prolif induced by proangiogenic GFs (VEGF)
2. Blood vessels sprout new vessels
3. Endothelial proteolysis of BM
4. Endothelial cell migration (chemotaxis)
5. Endothelial cell prolif
6. Endothelial maturation + tubular remodelling
7. Periendothelial cells recruitment

Question 12

What is the purpose of the ECM in fibrous repair?

Answer 12

1. Supports / anchors cells
2. Cell communication
3. Cell migration
4. Separates tissue compartments

Question 13

What are the 4 complications of fibrous repair?

Answer 13

1. Insuff fibrosis (wound dehiscence / herniation / ulceration)
2. Adhesion formation (blocks tubes)
3. X function (cirrhosis)
4. Overprod of scar tissue (tube block / joint contractures - constantly flexed joint)

Question 14

What does granulation tissue consist of?

Answer 14

1. Dev caps
2. Fibroblasts / myofibroblasts
3. Chronic inflamm cells

Question 15

What is the function of granulation tissue?

Answer 15

1. Fills gap + contracts n closes hole

2. Cap supply O2 / nutrients

Question 16

How is Type 1 Collagen formed?

Answer 16

1. Polypeptide alpha chains synth in ER of fibroblasts / myofibroblasts
2. Enzymatic mod steps: (vit C dependant hydroxylation)
3. Alpha chains align + crosslink –> procollagen triple helix
4. Soluble procollagen secreted
5. Procollagen cleaved –> Tropocollagen
6. Tropocollagen polymerises –> microfibrils –> fibrils
7. Fibrils –> fibres
8. Crosslinking –> tensile strength

Question 17

What causes Scurvy?

Answer 17

Lack of vit C (needed for vit C dependant hydroxylation) –> less crosslinking

Question 18

What happens in Scurvy?

Answer 18

X heal wounds
More bleeding
Tooth loss
Old wound reopen

Question 19

Is scurvy acquired or inherited?

Answer 19

Acquired

Question 20

What causes Ehlers Danlos?

Answer 20

Defective procollagen –> tropocollagen

Question 21

What happens in Ehlers Danlos?

Answer 21

Reduced tensile strength
Poor wound healing
Stretchy skin
Hypermobile joints

Question 22

Is Ehlers Danlos acquired or inherited?

Answer 22

Inherited

Question 23

What happens in OI?

Answer 23

Reduced bone tissue
Brittle bones (banana leg)
Blue sclerae (eye)
Impaired hearing
Dental abn

Question 24

Is OI acquired or inherited?

Answer 24

Inherited

Question 25

What causes Alport Syndrome

Answer 25

Abn Type 4 collagen

Question 26

What happens in Alport Syndrome?

Answer 26

Impaired ear chochlea and eye lens function | Renal failure

Question 27

Is Alport Syndrome acquired or inherited?

Answer 27

Inherited (X-linked so more in males)

Question 28

What wounds heal by Primary Intention?

Answer 28

Incised wounds w. apposed (side by side) edges

Question 29

Is there clot/ granulation tissue in Primary Intention?

Answer 29

Minimal

Question 30

What happens to the epidermis in Primary Intention?

Answer 30

Regen

Question 31

What happens to the dermis in Primary Intention?

Answer 31

Fibrous repair

Question 32

What are the risks of Primary Intention?

Answer 32

Trapping an infection causing abcess

Question 33

What wounds heal by Secondary Intention?

Answer 33

Infarcts / Ulcer / Abcess / Large wounds with unapposed edges

Question 34

What happens to the large clot in Secondary Intention?

Answer 34

Dries and becomes scab

Question 35

What happens to the epidermis in Secondary Intention?

Answer 35

Regen from base up

Question 36

What are the differences between Primary and Secondary Intention Healing?

Answer 36

1. Secondary prod more granulation tissue 2. Secondary prod larger scar 3. Secondary takes longer

Question 37

What are the local factors affecting healing and repair?

Answer 37

1. Size / location of wound 2. Blood supply 3. Infection 4. Foreign material 5. Radiation damage

Question 38

What are the systemic factors affecting healing and repair?

Answer 38

1. Age 2. Diet defic (prot. / vit C) 3. Diabetes / Obesity 4. CV status

Question 39

How does bone repair?

Answer 39

Callus formation

Question 40

How does the CNS repair?

Answer 40

No regen capacity | Glial cells prolif --> Gliosis

Question 41

How does the liver repair?

Answer 41

Acute damage --> regen | Chronic --> cirrhosis

Question 42

How does Cardiac / Smooth Muscle repair?

Answer 42

Permanent tissue so replaced by scar

Question 43

Why does skeletal muscle have limited regen ability?

Answer 43

Satellite cells