skin and wound healing Flashcards
name the 3 layers of the skin
epidermis, dermis and hypodermis
list the layers of the epidermis from supeficial to deep
corneum
lucideum
granulosum
spinosum
germinativum
function of the corneum
acid mantle protecting skin from bacteria
resistant to thermal, chemical, mechanical forces
function of the lucidum
forms boundary between corneum and granulosum
which parts of the body is lucidum found
palms of hands and soles of feet
function of granolsum
as cells travel through the nucleus is destroyed, cells flattended and cellular contents are converted into keratin
function of the spinosum
contain large oval nuclei.
langerhans cells here
function of the stratum germinativum or basale
forms junction between epidermis and dermis
what do the fibroblasts secrete in the superficial dermal layer
fibronectin and hyaluronic acid
what anchors the deep dermal layer to the subcut tissue
thick bundles of collage
what is the name of the junction between the epidermis and dermis
rete ridges/ pegs
what is contained with the subcut tissue
loose connective tissue
lots of fat cells
fewer blood vessels
nerve fibres and lymph vessels
one of the main functions of subcut tissue
attaches the dermis to underlying structures and ensures ongoing blood supply. provides cushioning.
list the 6 functions of skin
protection
thermoregulation
sensation
immune response
metabolism
blood reservoir
excretion
explain how the skin is protective in terms of a physical barrier
tightly joined epidermal cells, keratin and oily secretion block in and out
explain how the skin is protective in terms of a chemical barrier
acid mantle keeps pH low, preventing bacteria from multiplying.
langerhans fight infection
melanocytes protect DNA
explain how the skin is protective in terms of a biological barrier
macrophulges engulf and dispose of MO
which part of the hypothalamus controls heat loss
anterioir
which part of the hypothalamus controls heat production
posterioir
how does the skin thermoregulate
- muscle tone /shivering
- vasodilate/ constrict
what do langerhans cells do
fight bacteria
what do macrophages do
engulf and dispose MO
what do mast cells do
support immune system
who is at risk of VIT D deficiency
elderly
indoors
crohns
coeliac
list 5 functions of the skin that decline with age
injury response
cell replacement
sensory perception
VIT D production
immune response
what happens to the epidermis with aging
corneum becomes drier and more brittle
decreased langerhans - reduced immunity
decrease in melanocytes - dyschromia
alteration in pH - reduces acid mantle
what happens to the dermis during aging
decreased thickness
fewer cells
fewer blood cells
fewer fibres
sebum decreases
sweat gland production declines
factors that make individuals more susceptible to multiple skin conditions include:
normal aging
incontinence
reduced mobility
increased dependence
list 5 ways wounds can be classified
aetiology
location
type of injury
depth/ tissue loss
clinical appearance
list the 3 phases of wound healing
inflammation
proliferation
maturation
how long should the inflamm phase go on for
2-5 days
what are the main goals during the inflamm phase
haemostasis through a blood clot
oedema
what does the clot in the inflammatory phase release
histamine and other vasoactive chemicals causing vasodilation causing an influx of leukocytes, erthrocytes, plasma proteins
how long should the proliferative phase go on for
2-24 days
list the 5 processes that occur during the proliferative phase
angiogenesis
collagen synthesis
cross linking
epithelialisation
contraction
what is the function of angiogenesis
restoring blood flow to the wound. more oxygen, increased profusion
what is the function of collagen synthesis
keratinocyte migration results in strengthening the wound
how long does maturation go on for
24 days -1 or 2 years
when does maturation commence
only once wound is closed
describe primary intention
when there is minimal tissue loss and wound edges can be held together by sutures etc. scaring minimal
describe secondary intention
when the wound is left open for a period of time and allowed to close by epithelialisation and contraction. granulation occurs from wound base. epithelialisation occurs across the wound bed with formation of scar being thicker.
describe free flaps
complete segment with anastomosis of blood supply to vessels within wound
describe pedicle flaps
skin and subcut tissue is trasnferred to another site
list 6 risks for poor wound healing
malnutrition
elderly
diabetes
obesity
diseased state
why does diabetes impact wound healing
high BGLs can cause decreased functioning of WBC
less able to fight bacteria
damaged circulation… neuropathy.. damaged nerve endings.. numbness.. unaware
