integ exam 1

2 layers of dermis

papillary and reticular layer

3 mechanisms of lacerations

shearing

tension

compression

abrasion

tangential shearing of skin on rough surface

"road rash"

superficial wound but may cover larger surface area

acute vs chronic wounds

if phases of healing and sequence occur in orderly fashion \= acute

if wounds do not follow order of healing phases \= chronic

acute wounds

result of trauma or surgery

proceeds through healing phases

requires topical therapies

acute wounds examples

abrasions

avulsions

crush wounds

burns

cuts

lacerations

missle wounds

punctures

aging

decreased collagen

thinning epidermis

increase inflammation

decrease maturation phase

decrease in blood flow and lymph draining

Angiogenesis

formation of new vascular network

anti-inflammatories

delay epithelialization

reduces inflammatory process

avulsion (degloving)

portion of skin caught on sharp object while body is moving away and flap of skin is removed

most common in industrial setting

bariatric skin

circulation can be compromised because blood doesnt travel as efficiently through fatty tissue

delayed repair due to impaired skin barrier

increased stress on surgical sites

decreased oxygen

increased intra-abdominal pressure

cells contained in epidermis

melanocytes

langerhan cells

merkel cells

keratinocytes

chemical burn

acid/ bases/ caustic materials

chronic wounds

require topical therapies and appropriate supportive therapies

do not following healing phases

Co-morbidity

DM

end stage disease

neurological disease

impaired cognition

hepatic diease

collagen

protein made by fibroblasts

insoluble

found in connective tissue

gives epidermis durability

collagen via fibroplasia

major component of granular tissue filling in deficit

peak rates of collagen occur near end of first week

elastin also deposited

compression

high force with direct perpendicular contact causing jagged/shredded wound edges and tissue damage

ex: punch

contact burn

hot surface like stove

contraction

decreasing wound size

process occurs as wound closes due to loss fo tissue

begins around day 5

crush wounds

heavy objects falls onto persons body, splits skin and may shatter or tear underlying structures

ex: getting fingers caught in foor or feet fun over by car

cuts/ incisions

slice wound created by sharp object leaving straight/even edges

surgical wounds benefit from controlled trauma

deepest layer of epidermis

stratum basale

delayed primary intention

contaminated or dehisced wounds

delayed surgical closure

suturing/ skin graft/ flaps

Desquamation

shedding of dead keratinocytes

elastin

similar to protein

keeps skin flexible

electrical burn

wires or lightening

epibole

rolled wound edges

not a good thing

epidermis

outermost layer

protects body from environment

varies in thickness

eyelid epidermis thickness

.05 mm

factors that impact wound healing

wound environment

trauma

infection

nutrition

immunosuppression

oxygen/perfusion

co-morbidities

bariatric skin

aging

fibroplasia

replacement and reinforcement of new tissue

helps form scar tissue

dermal fibroblasts change into myofibroblasts into the wound and make collagen

flame

open flame

frostbite

excess cold

full thickness wounds

into hypodermis

they are measurable

function of the skin

protection from infection

conservation of body fluids

temperature regulation

excretion

secretion

vitamin D production

appearance

sensation

functions of the dermis

regulates temperature

supplies epidermis with nutrient saturated blood

large % of bodys water supply stored within dermis

consists of 2 layers

hemostasis

time: injury to 3 hours

function: platelets & fibrin stop bleeding

surrounding vessels vasodilate to try and get oxygen/nutrients to wound for healing

hepatic disease

decreased albumin and increased risk of dehiscence

high velocity projectiles

create negative pressure waves (cavitations) which causes expansion and collapse of tissue and more damage

3000 ft/s

how we heal

regeneration

repair

hypodermis

below dermis

thickness varies

if there is not an active infection

oral antiobiotics are useless

if wound healing follows the correct order of healing phases how long should a wound heal

2-4 weeks

immunosuppression

hinders initial inflammatory response

affects cell replication

infected wounds

bodys defenses are inadequate and types and number of organisms invade and flourish

infection

all wounds are colonized with bacteria but not all are infected

inflammatory phase

time: injury to 4-6 days

function:
-prevent infection
- clear away dead cells/bacteria
-neoangiogenesis

instances where oxygen/perfusion is reduced

impaired cardiopulm status

anemia

vascular insufficiency

smoking

hypovolemia

edema

keratin

tough protective protein that protects skin and creates water repellant seal

make up skin, hair and nails

keratinocytes

produce keratin

langerhan cells

help with immune response by fighting various microbes that invade the skin

layers of epidermis

stratum basale
stratum spinosum
stratum granulosum
stratum lucidum
stratum corneum

layers of skin

epidermis (5 layers)

dermis (2 layers)

hypodermis/subcutaneous layer

low velocity projectiles

create path of damage the size of projectile

1000 ft/s

maturation phase

time: 21 days to 1.5 years

tensile strength will reach 70-80% of original tissue by week 12

collagen & elastin formation continues

could have keloids and hypertrophic scars develop

melanin

pigment that contributes to skin color and absorbs UV light to protect DNA from damage

melanocytes

produce melanin

merkel cells

sensory receptor cells that are responsible for sensation of touch

missile wound

enters creating small wound with large exit wound

extend of damage depends on type/caliber/velocity/distance/tissue

Neoangiogenesis

new growth of blood vessels

supports new tissue formation

helps with removal of debris and waste products

Neovascularization

new blood supply

neurological disease

impairs sensation and mobility

nutrition

malnourished patient more susceptible to infection and hgh risk for skin problems

nutritional demand

protein

carbs/fat (energy)

vitamins/minerals

open fx

sharp pieces of bone penetrate and tear surrounding soft tissue and skin to create open wound

high energy injury, more superficial bones, among elderly

oxygen/perfusion

wounds require oxygen and cannot heal without

palms/soles epidermis thickness

1.5 mm

papillary layer

thin arrangement of collagen fibers

connected to epidermis via papillae

partial thickness wounds

into the dermis

phagocytosis

macrophages liquify cellular debris

neutrophils nearby

slough byproduct of this

phases of wound healing

hemostasis

inflammation

proliferation or granulation

remodeling/maturation

predictors of wound healing

surface area of wound decreases at least 39% in size at 2 weeks has greater chance of healing more quickly

Primary intention healing

surgical wounds

edges secured with staples, sutures, glue

proliferation phase

time: 4/6 days to 21 days

stages:
-neovascularization
-fibroplasia
-contraction
-reepithelialization

puncture wounds

deep and narrow

created by sharp objects (nails/ knives/ animal teeth)

high risk of contamination and infection

Reepithelialization

recreating permeability barrier

migration of epithelial cells across wound

basement membrane forms

provides water tight seal

proliferates by mitosis

regeneration

tissue replaced with like tissue

superficial wounds of epidermis/ partial thickness wounds into dermis will regenerate

also liver and GI

repair

scar formation

some tissues dont regenerate so you repair them by filling in with scar tissue

subcutaneous/muscle tissue

reticular layer

thick collagen fibers arranged parallel to skin surface to form strong elastic network

scald

boiling water or steam

secondary intention

follows wound healing cascade

closes without surgical intervention

shearing

small amount of force on small area resulting in minimal cell injury due to sharp instrument

ex: knife/ broken glass

shedding process

26-30 days in young

42-50 days in elderly

slough

dead tissue on a wound surface

special cells and structures contained within the dermis

blood vessels

lymph nodes

hair follicles

sweat glands

nerve endings

collagen

elastic

smooth muscles

sebaceous glands

hair follicles

SS of inflammation

swelling

redness

heat

pain

steroids

decrease tensile strength

inhibit regeneration

stratum basale

along surface of dermis

divides continuously

contains stem cells which divide and push new cells to surface

stratum corneum

15-20 layers of continuously shedding dead keratinocytes which are replaced from below

lipids seal dead cells togther to form barrier to keep water in/out

stratum granulosum

initiates keratinization which takes about 4 weeks

as keratinocytes move through stratum granulosum and lucidum they enlarge and flatten and adhere together

cells fuse together into tough durable materal that continues to surface to skin

stratum lucidum

appears only in thicker areas of skin (fingertips/palms/soles)

comprised of dead keratinocytes and protects against UV rays

stratum spinosum

prickle cells interlock and support skin

thickest layer of skin

involved in transfer of substances in and out of body

subcutaneous function

insulator

shock absorber

energy reserve

superficial wounds

wound is a separation of tissues from the body

affects the epidermis

tension

high amount of force at an angle with a blunt object which tears skin with significant tissue damage

trauma

any insult to the wound that may delay or interrupt healing process (inappropriate topical therapy)

continuous pressure to wound (interrupts blood supply & delays healing)

types of burns

flame

scald

contact

electrical

chemical

frostbite

types of chronic wounds

arterial ulcers

venous ulcers

pressure ulcers

neuropathic ulcers

types of full thickness wounds

diabetic wound

arterial wound

stage 3 pressure ulcers

stage 4 pressure ulcers

open surgical wound

full thickness burn

laceration