Repair and Regeneration (8) Flashcards Preview

EMS - Mechanisms of Disease > Repair and Regeneration (8) > Flashcards

Flashcards in Repair and Regeneration (8) Deck (19):
1

Healing by regeneration

Damaged cells replaced by like-tissues, returns to normal

2

Healing by repair

Damaged cells cannot be replaced by like fibrosis and scarring, loss of specialised function

3

Labile cell populations

High turnover, excellent regeneration (epithelia)

4

Stable/quiescent cell populations

Low turnover, can increase regeneration (liver, renal tubules)

5

Permanent cell populations

No turnover/regneration (neurones and muscle cells)

6

Stem cells

Prolonged self-renewal, asymmetric replication, crucial for regeneration, can have destruction of anatomical 'niche' (full thickness burns/radiation)

7

Control of regenration

Proliferation of stem cell, covering of defect, contact inhibition, complex control by growth factors (cell-cell and cell-matrix interactions)

8

Contact inhibition

Proliferate until touch each other

9

Repair by granulation tissue

Contains new capillary loops, neutrophils, macrophages, (myo) fibroblasts

10

(myo) fibroblasts

Lay down matrix components e.g. connective tissue, can acquire myofibrils and contract wound, synthesise collagen and ECM

11

Problems with wound contraction

Contractors after burns, oesophageal peptic strictures

12

Local factors inhibiting healing

Infection, haematoma, blood supply, foreign bodies, mechanical stress

13

System factors inhibiting healing

Age, drugs (steroids), anaemia, diabetes, malnutrition, catabolic states, vit C deficiency, trace metal deficiency

14

Healing by first intention

Clean, uninfected surgical wound, good haemostats, edges opposed (sutures/staples), can cause haematoma > bigger function destroyed

15

Healing by second intention

Wound edges not apposed, extensive tissue loss, apposition not physically possible, large haematoma, infection, foreign body, more florid granulation tissue reaction, more scarring

16

Fracture healing

Bones very vascular > haematoma (organised), remove necrotic fragments, osteoblasts lay down woven bone (callus), remodelling according to mechanical stress, lamellar bone replaces woven

17

Non-union fracture problems

Misalignement, movement, infection, interposed soft tissue, pre-existing bone pathology

18

Healing in brain

Supporting tissue is glial cells rather than collagen/fibroblasts, damaged tissue often removed > cysts, gliosis rather than scarring, neurons are terminally differentiated

19

Control of healing

Complex network of cytokines