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Flashcards in Regeneration and reapir Deck (23):
1

What are the 3 tissues of the body ?

Labile tissue- Proliferate, replaced . Surface epithelia and Lining of mucosa
Stable- Low level normally but can proliferate in stimuli to reconstruct tissu- Liver, Kidney and pancreas
Permanent- Left cell cycle - Neurones , skeletal and cardiac msucles

2

What is asymmetric replication

shown by stem cells . Daughter cell remains as stem cell but the other is a mature end cell

3

What are embryonic Stem cells ?

Totipotent- give arise to any tissue

4

What are adult stem cells?

Unipotent- only into 1 form of adult cell

5

What are haematopoietic stem cells ?

Multipotent - several cells in adult stem cells

6

What happens in regeneration in Permanent tissue, especially in neurones .

Scaring - stem cells cant perform
Gliosis - Glial cells fill in gaps

7

What happens in cell cycle for Stable tissue?

G0 to G1 . stem cells proliferate slowly but persistently

8

Why might fibrous regeneration occur?

collagen framework is destroyed
On going chronic inflammation
Necrosis of special parenchymal tissue

9

What are the processes of Fibrous repair?

1. Phagocytosis
2. Growth of endothelial cells which allows angiogenesis
3. Fibroblasts and myofibroblasts -collagen - contraction- Granulation tissue
4. Granulation tissue - less vascular - matures into fibrous scar
5. Scar shrinks due contraction of fibrils

10

Steps of collagen synthesis

1. preprocollagen in cell
2. modified to pro-collagen which goes into Triple helix
3. Secreted from cell and cleaved to collagen
4. Cross linking

11

Scurvy Pathology

Vit C needed for hydroxylation of pro-collagen - prolyl hydroxylase . Proline to hydroxy proline

12

Ehlers- Danlos Syndrome

Six inherited disorders collagen lack tensile strength
Organs weak - ruptures

13

Osteogenesis imperfecta

not enough collagen made - blue sclera - translucent, brittle bone

14

Alport Syndrome

Type 4 collagen is abnormal . Glomerular , lens of eye and cochlea - chronic renal failure

15

What are growth factors and what are they coded by?

Short distance - autocrine or paracrine or endocrine stimulating cell proliferation . coded by proto oncogenes

16

What are the types of growth factors

Epidermal
Vascular Endothelial
Platelet Derived- Increase Fibroblasts , SMC and Monocytes
Tumours Necrosis factor- Fibroblast migration , prof and collagenase

17

What is contact inhibition ?

Cells replicate until they touch other cells

18

What allows cell to cell adhersion ?
Cell to EXCM?

Cadherins
Intergrins

19

When does primary intention occur?

Closed , incisional , non -infected sutured wounds

20

what is the process of healing by Primary Intention ?

1. Heamostasis
2. Inflammation
3. Migration of cells
4. regeneration
5.early scarring
6. Scar Maturation

21

When is is healing by secondary intention occurring ?

Wounds with tissue loss
Excisional surgery
more intense inflammation - Granulation tissue for the margins
contraction . Thinner epidermis .

22

Stages of healing bone fractures

1. Haematoma
2. Fibrin mesh of granulation tissue
3. Soft callus - Fibrous tissue and cartilage
4. Hard callus - oestoblasts
5. Formation of lamellar bone- Haversian canals and Volkmans
6. Remodelling

23

Factors affecting repair:

Local: Size , Blood supply, Protecetion , surgical technique
Systemic: Age , ANAEMIA, DIABETES, drugs