Lecture 1 - Healing Flashcards
The skin receives ____ of resting cardiac output
1 / 3
Where is the thinnest skin located?
Thickest?
Eyelid/eardrum
Hands/feet
Describe the layers of the skin
Epidermis: 5 thin layers
Dermis: 2 thick layers
T or F: the epidermis is vascular
F
It is avascular
Which part of the skin produces vitamin D
Epidermis
Complete renewal of epidermis takes _____ days
45-75
What cell mainly handles re-epithelialization
Keratinocyte (90% of it)
What is a melanocyte
pigment producing
Merkel cells
Mechanoreceptors for light touch
What are langerhan’s cells
Immune system cells in skin
derived from bone marrow
T or F: The dermis is vascular
T
Where are superficial lympathatics and epidermal appendages contained in the skin
Dermis
Where do blisters occur
Between papillary dermis and the stratum basale
called: Rete ridges
What layer of the skin provides sensation
dermis
What is the main cell of the dermis
Fibroblast
produces collagen and elastin
What is a macrophage
Peak 48-72 hours after injury,
housed in dermis,
clean cellular debris and fight infecion
White blood cells
Mastcells
Both housed in dermis
WBC- fight infection
Mast cell - produce histamine
Adipose tissue is highly ___________
Vascular
Shiney yellow/white little balls
Fascia looks like what
shiny white or yellow strands when healthy
A stage 2 pressure injury is ________-thickness
partial
A stage 3 or 4 pressure injury is ________-thickness
full
What are the 4 phases of wound healing
Hemostasis
Inflammation
Proliferation
Maturation/remodeling
What are the cardinal signs of inflammaiton
Edema
Rubor
Warmth
Pain
Decreased function
What is the first cell to arrive at a site of injury
PMN Polymorphonuclear neutrophils
Stimulates vascular growth and fibroblast migration, secretes inflammatory mdiatiors
What do macrophages do
Direct repair process, kill bacteria and pathogens
What cells form a plug to stop bleeding
platelets
What are the signalling proteins of the inflammation phase called?
cytokines
The proliferation phase starts _____ hours after an injury
it consists of what 4 events
48 hours
Angiogenesis
Granulation tissue formation
Wound contraction
Epithelialization
What cells are responsible for wound contraction
Myofibroblast
What heals faster: circular wound or square/rectangular wounds
Square/rectangle
The maturation and remodeling phase for a wound can take up to _______, most change occurs within _______
2 years
6-12 months
The new collage put down in the remodeling phase is type _____, the old collage is type ______ and is broken down by collagenase
Type 1
Type 3
Fully remodeled collagen is only ___% as strong as the original, if it is broken and repaired again it is __% as strong
80%
64%
(keeps being 80% as strong each generation)
What are MMP (Matrix Metalloprotease)
Inflammatory mediatiors (the boss of the wound)
Takes part in all 3 healing phases
Play a large role when woound becomes chronic (too many of them)
The epidermis normally has a _______ charge
A wound usually has a ______ charge
Electronegative
Positive
Note: this current difference is what starts wound healing cascade
Intact skin has a PH of what
Damage to skin can do what?
4-6.5
Increase PH/loss of acidity
What can increase skin acidity
Urine/stool
Systemic disease
Eczema, dermatitis can _______ skin acidity
Decrease acidity (higher ph)
What is wound primary closure (surgery)
Wound is cleaned and edges are approximated and closed
What is secondary wound closure
Wound is left open to heal on is own through the 3 phases
What is delayed primary closure
Where the surgeon leaves the wound open temporarily to monitor for infection before eventually closing it
What is dehiscence
Where primary wound closure from a surgery opens back up
Hypogranulation vs hypergranulation
Hypo- wound fails to granulate
hyper- granluation occurs outside wound
A chronic wound is defined by medicare as _____
taking more than 30 days to close
Technical definition of chronic wound (not medicare)
Wound is stuck in a phase of healing with no progress
What are senescent cells
Dr flynns brother
useless cells
usually found in chronic wounds
Chronic wounds typically have ______ levels of MMP
higher
+dont respond to growth gactor
+lower level tissue inhibitors of matrix metalloprotease (TIMPs)
Why do you want to do change the dressing of a wound as less-frequent as you can?
To avoid changing temp
Optimal temp for wound healing?
When is it too cold?
37-38C
Below 12C
Should you let a wound “air out”
No, wounds cannot become too dry
wounds must stay hydrated
What is normal water intake for a person?
Normal intake if u have a wound?
30-35ml per kg of BW
2.7-3.7L per day
How can you tell if someones dehydrated
1% decrease in bodyweight
decreased urine output/dark color
decreased skin turgor
Why is vitamin A important?
Improves tensile strength of tissue
increases collagen synthesis
Helps w/ longterm corticosteroid use
note: can damage liver if too much
Why is vitamin C important?
absorb iron/ antioxidant/ synthesis collagen/ capillary integrity
Why is vitamin E important
Antioxidant/ decrease inflammation phase/ enhance immune function/ decreases platelet adhesion
Why is Vitamin K important
Essential for blood clotting
How does Zinc help wound healing
Aids in collagen and protein synthesis and cell proliferation/ normal immune function
Why is iron important
O2 transport, immune function
Why is copper important
Required for hemoglobin synethsis and iron absorption
why is magnesium important
Deficiency can cause HTN and vasoconstriction
often caused by diabetes/alcoholism/diarrhea/dehydration
Why is calcium important
Required for fibrin synthesis
What happens at these Loss of lean bodymass percentages?
10%
20%
30%
40%
10%- impaired immunity
20% - impaired healing and thin skin
30% - no healing, new wounds can form
40%- death
What do creatinine levels indicate
Kidney function
What do albumin levels indicate
protein deficiency
What do prealbumin levels indicate
same for serum transferrin levels
see how change in protein in impactng patient
serum transferrin- looks at protein status/recent changes
What do C-reactive protein levels indicate
Indicates inflammation
What do BUN levels indicate
decreased healing
What do blood glucose levels indicate
increase risk for ulcer, infection, impaired healing
