Normal wound healing and types of wound

Question 1

How long does the lag phase of wound healing last?

Answer 1

1-5 days

Question 2

What is the principle process occurring during the lag phase of wound healing?

Answer 2

Inflammation

Question 3

Haemostasis occurs within which phase of would healing?

Answer 3

Lag/ inflammatory - IMMEDIATELY

Question 4

How do vessels respond to injury?

Answer 4

Transient vasoconstriction then vasodilation after 5-10 minutes

Question 5

Describe the primary clot formed during haemostasis.

Answer 5

Aggregate of fibrin, clotting factors and platelets

Question 6

Acute cells of inflammation

Answer 6

Neutrophils

Question 7

How do neutrophils act when they enter a wound site?

Answer 7

Degradation of necrotic tissue via release of proteolytic enzymes and control of bacterial infection via superoxide radicals

Question 8

Chronic cells of inflammation

Answer 8

Lymphocytes and plasma cells

Question 9

Intermediate cells of inflammation

Answer 9

Monocytes -> Macrophages

Question 10

How do macrophages act when they enter a wound site?

Answer 10

Remove degenerate neutrophils, necrotic tissue and debris by phagocytosis. Secrete regulatory factors of wound healing

Question 11

How long does the repair phase of wound healing last?

Answer 11

6-16 days

Question 12

What are the three aspects of the repair phase of wound healing?

Answer 12

Connective tissue repair, wound contraction and epithlialisation

Question 13

Describe the repair of connective tissue in a wound

Answer 13

Fibroblasts migrate into the wound secreting ground substance which replaces the primary clot. Collagenous (t3 initially then to t1) ECM is put down. Fibroblasts apoptose which forms a granulation tissue scar. Secondly angiogenesis occurs (these disintegrate after used)

Question 14

When does wound contraction occur?

Answer 14

5-9 days post injury

Question 15

Describe the cells associated with wound contraction.

Answer 15

Specialised myofibroblasts containing actin microfilaments

Question 16

When does scar remodelling occur in a wound?

Answer 16

14-16 days post-injury

Question 17

Remodelling results in what changes in the wound site?

Answer 17

Reduced cellularity, thickened collagen bundles, cross-linking and reorientation along the lines of tension.

Question 18

How does hypoproteinaemia affect wound healing?

Answer 18

Reduced cell proliferation and ground substance production

Question 19

How does hypovolaemia affect wound healing?

Answer 19

Reduced delivery of oxygen and nutrients to the wound site

Question 20

How does reduced oxygen tension affect wound healing?

Answer 20

A high oxygen demand within wound cells (high metabolic demand)

Question 21

How does uraemia affect wound healing?

Answer 21

Reduced cellular metabolism and therefor granulation tissue and epithelial formation.

Question 22

How does steroid therapy affect wound healing?

Answer 22

Reduced protein synthesis, capillary growth, fibroblast proliferation and epithelialisation. Inhibit inflammation!

Question 23

How does a vitamin C deficiency affect wound healing?

Answer 23

Collagen synthesis (remember ascorbic acid)

Question 24

How does a Zinc deficiency affect wound healing?

Answer 24

Reduced epithelial cell and fibroblast multiplication - reverse transcriptase and DNA polymerase

Question 25

How do cytotoxic drugs/ radiotherapy affect wound healing?

Answer 25

Drugs target and kill actively dividing cells such as those in a healing wound

Question 26

How does dehydration affect wound healing?

Answer 26

Drying of wound surface can reduce cellular migration and proliferation

Question 27

How does bacterial infection affect wound healing?

Answer 27

Increases inflammation, affects wound pH, reduced fibroblast activity, degradation of ECM and ground substance

Question 28

How does a antiseptic solutions affect wound healing?

Answer 28

Contain cytotoxic detergents

Question 29

How does skeletal muscle respond to injury?

Answer 29

If little disruption to the sarcolemma then regeneration is possible. If the sarcolemma is severely disrupted then fibrous tissue bridges the gap

Question 30

How do peripheral nerves respond to injury?

Answer 30

If cut sprout axons which grow down the endoneural tube

Question 31

Clean wound

Answer 31

Elective surgical wounds not entering the respiratory, urogenital or gastrointestinal tracts with no break in asepsis and primary closure

Question 32

Clean-contaminated wound

Answer 32

Surgical wounds involving the respiratory, urogenital or GI tracts without significant contamination or only minor breaks in asepsis

Question 33

Contaminated wound

Answer 33

Fresh (

Question 34

Dirty wound

Answer 34

Old (>4-6hr) traumatic wounds. Or traumatic wounds contaminated with foreign material or severe amounts of devitalised tissue. Surgery in the presence of abscessation

Question 35

Abrasion

Answer 35

Partial thickness, loss of epi and part of dermis

Question 36

Avulsion

Answer 36

Tearing of tissue from its attachment

Question 37

Degloving injury

Answer 37

Low-velocity avulsion of skin due to rotational forces (RTA)

Question 38

Incision

Answer 38

Sharp trauma, smooth-edged wound, minimal tissue trauma

Question 39

Laceration

Answer 39

Sharp trauma, irregular wound, tearing of tissues and trauma to underlying tissue

Question 40

Puncture wound

Answer 40

Minimal superficial damage, substantial deeper damage, significant risk to deep organs

Question 41

Burn

Answer 41

HOT/ COLD WOUNDS