• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

Card Range To Study

through

image

Play button

image

Play button

image

Progress

1/73

Click to flip

Use LEFT and RIGHT arrow keys to navigate between flashcards;

Use UP and DOWN arrow keys to flip the card;

H to show hint;

A reads text to speech;

73 Cards in this Set

  • Front
  • Back
Define 'healing'
The replacement of dead and damaged cells by healthy tissue
The replacement of dead and damaged cells by healthy tissue
Healing
What are the two ways healing is achieved?
Regeneration
Repair
What precedes healing?
Haemostasis and acute inflammation
Haemostasis must be achieved before _______ can occur
Healing
What is haemostasis? How does it occur?
A complex process which causes the bleeding process to stop.

Occurs via formation of a blood clot in the would
During acute inflammation, what do neutrophils and macrophages do? (3)
They phagocytose debris, secrete growth factors and other chemical mediators
What produces growth factors? (4)
Fibroblasts, platelets, macrophages and endothelial cells
Give an example of growth factors (3)
Epidermal growth factor
Cytokines
Platelet-derived growth factor
What is contact inhibition?
The natural process of arresting cell growth when two or more cells come into contact with each other
injured cells are replaced by ___________ cells of the same type
parenchymal
What are parenchymal cells?
A cell that replaces injured cells of the same type
What are the three types of cell responsible for regeneration?
Stable (quiescent) cells
Permanent cells
Labile cells
Cells that constantly divide during life to replace like cells that are being lost
Labile cells
Give three examples of labile cells
Skin epithelial cells, gut epithelial cells, bone marrow cells
Cells that have a low level of replication under normal circumstances
Can switch to rapid levels of replication with the correct stimulus
Stable (quiescent) cells
Give examples of stable (quiescent) cells (3)
Epithelial cells of kidney, liver, etc.
Fibroblasts
Smooth muscle
Cells either incapable of mitosis or organised replication
Permanent cells
Give three examples of permanent cells. Think!
Neurones
Skeletal and Cardiac Muscle
What is necessary for regeneration to work?
The supporting architectural framework (i.e. the basement membrane) need to be in tact
Pure regeneration after injury is common/rare. Why?
Rare. For regeneration to take place, basement membrane needs to be in tact --> Not usual after injury
Progresses centrally over time
Regeneration
The replacement of injured cells by fibrous connective tissue
Repair
Repair is less common than regeneration T/F
F
Often occurs when supporting framework of labile, permanent or stable tissue cells is destroyed
Repair
How does repair occur?
Via granulation tissue formation
What is granulation tissue?
The perfused (Supplied with a fluid), fibrous connective tissue that replaces a fibrin clot in healing wounds. Granulation tissue typically grows from the base of a wound and is able to fill wounds of almost any size it heals.

It is composed of:
extracellular matrix,
immune system cells
vascularisation components
The perfused (Supplied with a fluid), fibrous connective tissue that replaces a fibrin clot in healing wounds. Granulation tissue typically grows from the base of a wound and is able to fill wounds of almost any size it heals.

It is composed of:
extracellular matrix,
immune system cells
vascularisation components
Granulation tissue
What cells does granulation tissue contain?
Fibroblasts and macrophages
Involved in angiogenesis
Granulation tissue
What is VEGF?
Vascular endothelial growth factor - the most important stimulator of angiogenesis
The most important stimulator of angiogenesis
VEGF
Macrophages secrete growth factors T/F
T
Migrate and proliferate rapidly
Replace cell debris
Produce collagen and other important components of ECM
Fibroblasts
Repair begins in the first 48 hours after injury T/F
F, it begins in the first 24 hours
How long does it take for a scar to form?
4-7 weeks
Collagen increases during repair, cellularity decreases over time in granulation tissue. T/F
T
What does 'intention' mean in regard to wounds?
The healing process of a wound
Occurs when uninfected wound without tissue loss is closed promptly by sutures
Healing of skin by primary intention
Blood from cut vessels fills gap
Fibrin forms blood clot which binds cut surfaces
Clot at surface dehydrates to form scab
Would now sealed from further damage
Immediate healing action by primary intention
Neutrophils migrate from incision margin
Phagocytose any debris
Epidermis thickens at edge of wound via cell proliferation
Spurs of cells migrate across gap
Fuse at centre to form continuous layer
(i.e. epithelial cell regeneration
Healing of skin by primary intention 24-48 hours on
Macrophages replace neutrophils
COntinue phagocytosis
Granulation tissue forms at incision margin
COllagen fibres present at edge of wound but verticlal orientated
Would red - 'livid' - macroscopically
Continued epithelial regeneration
Stratification of epithelium
Healing of skin by primary intention by day 3
Granulation tissue fills wound space
Collagen more abundant and bridging gap
Epidermis normally stratified and keratinised
Healing of skin by primary intention by day 5
Granulation tissue matures
Continued accumulation of collagen
Vascularity and macrophages reduce
Scar becomes paler macroscopically - 'blanching'
Healing of skin by primary intention during second week
Collagen at maximum
Scar complete
Tensile strength
_____

Collagen remodels
Cross-linking and thickening of fibrils
Fibrils organise along lines of stress
Tensile strength increased to 80% of original tissue
Healing of skin by primary intention by the end of 1 month, and the following few months
Occurs in an open wound with excessive tissue lost
Skin healing by secondary intention
Would defect larger
Process slower
Larger area of necrotic debris leads to more intense inflammation
Larger would leads to larger area of granulation tissue
Granulation tissue present at surface as epithelial regeneration slower
Would contraction occurs
Differences between secondary and primary intention wound healing
Healing of bone fractures - capable of complete regeneration T/F
T, unless adverse factors are present
Bleeding from ruptured vessels
Clot formation fills wound gap and surrounds area
Immediate action from bone fracture healing
Neutrophils and macrophages migrate from incision margin
Phagocytose any debris
Healing of bone fractures within 24-48 hours
Formation of granulation tissue
Proliferation of cartilage cells from edge of wound
Cartilage and granulation tissue fill wound site
Known as 'provisional callus' or 'procallus'
Healing of bone fractures by day 4
Cartilage begins to calcify
Osteoblasts lay down osteoid
Forming firstly a 'fibrocartilaginous callus'
Then a 'bony callus'
Weak as composed of woven (disorganised) bone
Healing of bone fractures during second weak
Remodelling of bony callus
Osteoclastic and osteoblastic activity
Lamellar (organised) bone replaces woven bone
Marrow cavity restored
Bone strength returns to normal
No macroscopic or microscopic evidence of injury
Healing of bone fractures during weeks 2-7
Healing is impaired by two different factors, name them
Local and systemic factors
What are local factors that can affect healing? (4)
Infection (most common)
Mechanical factors (early movement)
Foreign material (can't be phagocytosed and can cause infection)
Size, location and type of wound
What are the systemic factors that can affect healing? (5)
Nutrition
Diabetes Mellitus
Circulation
Glucocorticoid (steroid) drugs [Can have anti-inflammatory effect]
Immune suppression
Which nutrients are especially important in healing?
Protein, Vitamin C and Zinc
What are the complications of wound healing?
Would ulceration (often due to poor vascularity)
Wound dehiscence
Stretching of scar

Excessive growth of scar elements
Keloid/hypertrophic scar
Exuberant granulation tissue (proud flesh)
Bleeding from ruptured vessels
Clot formation fills wound gap and surrounds area
Immediate action from bone fracture healing
Neutrophils and macrophages migrate from incision margin
Phagocytose any debris
Healing of bone fractures within 24-48 hours
Formation of granulation tissue
Proliferation of cartilage cells from edge of wound
Cartilage and granulation tissue fill wound site
Known as 'provisional callus' or 'procallus'
Healing of bone fractures by day 4
Cartilage begins to calcify
Osteoblasts lay down osteoid
Forming firstly a 'fibrocartilaginous callus'
Then a 'bony callus'
Weak as composed of woven (disorganised) bone
Healing of bone fractures during second weak
Remodelling of bony callus
Osteoclastic and osteoblastic activity
Lamellar (organised) bone replaces woven bone
Marrow cavity restored
Bone strength returns to normal
No macroscopic or microscopic evidence of injury
Healing of bone fractures during weeks 2-7
Healing is impaired by two different factors, name them
Local and systemic factors
What are local factors that can affect healing? (4)
Infection (most common)
Mechanical factors (early movement)
Foreign material (can't be phagocytosed and can cause infection)
Size, location and type of wound
What are the systemic factors that can affect healing? (5)
Nutrition
Diabetes Mellitus
Circulation
Glucocorticoid (steroid) drugs [Can have anti-inflammatory effect]
Immune suppression
Which nutrients are especially important in healing?
Protein, Vitamin C and Zinc
What are the complications of wound healing?
Would ulceration (often due to poor vascularity)
Wound dehiscence
Stretching of scar

Excessive growth of scar elements
Keloid/hypertrophic scar
Exuberant granulation tissue (proud flesh)

Contracture

Persistent cavity
What causes a keloid/hypertrophic scar?
Excess collagen leading to a 'tumour like' outgrowth
What is exuberant granulation tissue (or 'proud flesh')?
Formation of excess granulation tissue
Blocks regeneration of epithelium
Blocks regeneration of epithelium
Proud flesh
Exaggeration of normal wound contraction
Distorts surrounding structures
May impair movement or function
Contracture
Failure of healing process due to presence of factor inhibiting healing
Persistent cavity - non-union