Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

M202 > W25 Wound Healing (GN) > Flashcards

W25 Wound Healing (GN) Flashcards

1
Q

Structure of the skin:
What are the layers?

A

Epidermidis - The outermost layer
Dermis- Connective tissues
Hypodermis/subcutaneous layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is contained within the dermis? (4)

A
  • Elastin and collagen fibres (stretch & strength)
  • Blood vessels and nerve terminations
  • Hair follicles
  • Sebaceous/sweat gland
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the different types of wounds? (3)

A

Superficial – Grade I
-only the epidermis
Partial Thickness – Grade II
-Involves the epidermis and the dermis
Full Thickness – Grade III and IV
-Exposed to tendons, muscles & bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Physiology of wound healing
What are the 4 time-dependent phases of wound healing?

A

1 Haemostasis phase
2 Inflammation phase
3 Proliferation or granulation phase
4 Remodelling phase

  • The process in not linear - phases which may overlap
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the Haemostasis phase?

A
  • The body responds quickly to any disruption of the skin’s surface
  • It occurs in 3 consecutive steps:
    1. Vasoconstriction
  • Stop bleeding by localised vasoconstriction
    2. Primary haemostasis
  • platelet plug formation
    3. Secondary haemostasis
  • Activation of the coagulation cascade = thrombus formation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Haemostasis phase - vasoconstriction

A

Immediate response to reduce haemorrhage - 5/10 min post-injury

  • The damaged endothelium releases endothelins, prostaglandins
  • Induced vasoconstriction in vascular smooth muscle
  • Blood flow reduction at the injury site until hypoxia occurs
  • Hypoxia triggers nitric oxide release = vascular vasodilation = restore normal blood flow
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Primary haemostasis

A

Platelet plug* Vascular injury exposes dermis extracellular matrix 
attracting platelets
* Platelets adhere to damaged endothelium via adhesion
molecules (vWF)  Activation

Release of granules containing:
 ADP - attracts more platelets
 serotonin - vasoconstriction
 thromboxane A2 - platelet aggregation
Platelet plug
* In intact skin, endothelial cells release NO2, to prevent platelet activation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Secondary haemostasis:
What does the cascade lead to the conversion of?

A
  • Injured blood vessels expose tissue factor
  • Tissue factor activates the extrinsic pathway of coagulation
    Cascade leads to the conversion of prothrombin into thrombin, which cleaves fibrinogen into fibrin
  • Fibrin forms a stable mesh, reinforcing the platelet plug
    = Thrombus formation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Inflammation phase
What are the aims? (3)
How long does this phase last?

A
  • minimizes infections and removes debris
  • activates keratinocyte regeneration
  • promotes new vessel formation = Angiogenesis
  • It lasts for the initial 4-6 days
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Inflammation phase:
What is it marked by?

A
  • Oedema =localized swelling due to the accumulation of fluid in the tissues
  • Erythema =redness in the affected area, caused by enhanced blood flow
  • Heat =due to metabolic reactions
  • Pain =nociceptors are activated by tissue injury
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Inflammatory phase
Early phase - (within 1 day)

A
  • Damaged tissue cells release chemokines  activating neutrophiles
     produce factors to further neutrophil infiltration
     release toxic proteolytic granules to kill microbes
     phagocytosis, by engulfing cell debris or microbes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Late phase - (after 24-48 h)
What occurs?

A
  • Macrophages replace neutrophils, which undergo cell death
  • Neutrophiles clearance = critical for inflammation resolution
  • Neutrophil persistence = chronic wounds
  • Macrophage exert many essential activities
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Proliferation phase (from 4 to 21 days)

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Remodelling phase (from the 21th day to 2 years)

A

Aims
 Further wound contraction
 Scar maturity

ECM reorganization
* Macrophages break down ECM excess and engulf ECM tissue debris =tissue reshape
* Replacing collagen III of the granulation tissue with the stronger collagen l

  • Granulation tissue retracts, scar matures and fades
  • Tissue regains up to 80% of the initial strength and functionality
  • Excessive collagen deposition = Abnormal scarring spontaneously regress or not
    (Keloid scars)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Wound healing complications:
What are acute wounds?
What are chronic wounds?

A

acute:
Wound healing complications
* usually heal in an ordered, timely fashion

chronic:
* Impaired wound healing. Wounds that do not heal within 3 months
- Fail to progress through a timely repair sequence

Clinical challenges – Info only
* People over the age of 60
* Diabetic ulcers, pressure ulcers, venous stasis ulcers, etc
* Microbial biofilm formation = impairing debridement and causing necrosis
-Healing cannot proceed until biofilms and necrotic tissue has been removed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the factors affecting healing?
Local & Systemic?

A

Local
 Tissue oxygenation/Blood flow
 Infection
 Foreign body
 Oedema, elevated tissue pressure

Systemic
 Age and gender
 Sex hormones
 Stress
 Diseases
 Nutrition & Obesity
 Medication
 Alcoholism and smoking
 Immunocompromised conditions

17
Q

What is wound dressing?
What are the Properties of an ideal wound dressing?

A
  • A sterile pad or compress applied to a wound to promote healing and protect the wound
    from further harm
  • Remove excessive exudate and maintaining a moist environment
  • Allow gaseous exchange (O2, CO2 and water vapour)
  • Thermally insulating
  • Be impermeable to micro-organisms
  • Be free from either particulate or toxic substances
  • Not adhere to the wound, avoiding damaging the granulating tissue
18
Q

Wound dressing choice factors

A
  • Type of wound/cause
  • Wound characteristics (e.g. granulating, epithelialising, sloughy, necrotic)
  • Treatment goals (e.g. to manage exudate, manage infection risk)
  • Anatomical location
  • Patient-related factors (e.g. pain levels, fragile skin, capacity to self-care)
  • Cost
19
Q

Primary/ secondary dressings

A

Primary wound dressings – applied directly over the wound
* Secondary wound dressings - Not applied to the wound, covering the primary dressing
Influencing factors

20
Q

What are the types of wound dressings? (8)

A

Gauze, Transparent films, Foam, Alginates, Hydrocolloids, Hydrogel, Antimicrobial dressings

21
Q

Wound dressings:
When is Gauze used?

A

Gauze
 Limited role in modern wound care
 For infected wounds that require frequent
dressing changes
 Not effective to promote moist wound healing

  • Bandage: Material used to secure a dressing, medical device or splint
     Support bandage: Provides support and light compression.
     Compression bandage : Used to assist venous return to the heart.
22
Q

Wound dressings:
What are transparent films?

A

 Allow O2 to penetrate wound and release wound moisture
 Helps with autolytic debridement
 Good for partial thickness wounds
 Not suitable for heavy draining woundsi

23
Q

Wound dressings :
When is foam used?

A
  • Foam
  • Non-occlusive dressing
  • Highly absorbent (as sheets, island dressings and cavity fillers)
  • Less frequent dressing changes—up to 7 days
  • Use on draining
  • Don’t use on dry wounds
24
Q

Wound dressings:
When are alginates used?

A

Alginates
* form soft gel in presence of exudate - provides moist environment
* Highly absorbent – for wounds with moderate level of exudate
* Can remain in the wound bed for days
* Not suitable for dry necrotic wounds

25
Q

Wound dressings:
When are hydrocolloids used?

A
  • Prevent skin from losing moisture
  • Contain gelatin or pectin that swells with exudate
  • Waterproof—helps with autolytic debridement
  • Particles of the dressing can become lodged in the wound bed
  • Suitable for clean granulating or sloughy/necrotic wounds
26
Q

Wound dressings:
When is Hydrogel used?

A
  • Viscous amorphous gels donating moisture to the area
  • Ideal to re-hydrate and soften dry necrotic eschar
  • Provide some soothing, pain relieving properties
  • Consists mostly of hypertonic saline (as sheets or as a gel)
    -helps with autolytic debridement
27
Q
  • Antimicrobial dressings
    What is used?
A

o Medical grade honey
* Broad spectrum antibacterial activity. Lower the pH
* Anti-inflammatory activity, stimulation of granulation, odour management and pain reduction
o antiseptics (not antibiotics). E.g.iodine, silver or honey

28
Q

When are bandages used?
What are the 2 types?

A
  • Bandage: Material used to secure a dressing, medical device or splint
  • Support bandage: Provides support and light compression.
  • Compression bandage : Used to assist venous return to the heart.
29
Q

Which one of the following is not considered an ideal property of wound dressings?

A

M202 (72 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions