EXAM 1 Pathophysiology of Skin and the Integumentum Flashcards
layers of skin
- epidermis
- basement membrane
- dermis
- subcutaneous
pilosebaceous unit
- 2-4 hairs
- Sebaceous gland, apocrine sweat gland
- Arrector pili muscle
- At junction of the papillary and reticular dermis (gives pink color of skin)
- Perfuses the dermal papilla
Subpapillary plexus/upper horizontal network
- Provides blood to the entire dermis
- At the dermal-subcutaneous interface
- Larger blood vessels
Lower horizontal plexus
_________ also in dermis, contribute to immune defense
Lymphatics also in dermis, contribute to immune defense
regular/linear wounds caused by a clean, sharp-edged object i.e. scalpel, piece of glass
incisions
are irregular tear-like wounds caused by blunt trauma
lacerations
superficial wounds to the epidermis and dermis caused by friction (scraped off) i.e. scrape, road rash
abrasions
occur when skin is forcibly torn off or detached from its normal point of attachment i.e. where nail torn off, elderly catching thin skin on something
avulsions
caused by an object puncturing the skin
puncture wounds
caused by an object puncturing the skin and deeper tissues i.e. bullet wound, shrapnel
penetrating wounds
occur when the skin is intact but trauma to underlying structures has occurred
closed skin wounds
caused by blood vessel damage causing blood to collect under the skin
menatomas
smallest for of hematoma to largest
- petechiae
- purpura
- ecchymosis
Hematomas caused by external trauma
contusions
caused by a great amount of force applied to tissue, injuring the compressed tissues (may be open)
crush injury
result from healing of injured tissues, but depending on a number of factors (e.g., heredity, amount of injury, stresses on site of healing), can vary in the form
all scars
caused by the presence of a large amount of vasculature (newer)
hyperpigmented scars
caused by loss of vasculature (older)
hypopigmented scars
scars which continue to thicken due to excessive collagen formation but do not extend beyond the boundary of the original wound
hypertrophic scars
result from overgrowth of granulation tissue which is slowly replaced by mature scar; firm, rubbery lesions
keloids
sunken recess in the skin, caused when underlying structures are lost, such as fat or muscle; associated with acne, chickenpox, MRSA – deeper structures are affected
atrophic scars
parallel to the orientation of collagen fibers of the reticular dermis
Langer’s lines
Incisions and excisional biopsies heal best with less scarring when made ________ to the Langer’s lines
Incisions and excisional biopsies heal best with less scarring when made parallel to the Langer’s lines
Heat induced injury of the skin and subcutaneous tissues (thermal injury)
burns
Burn injury determined by:
- Length of exposure
- Temperature of heating agent
- Surface area involved
these burns heal by epithelial regeneration
epidermal burns
these tissues heal by scar replacement (second intention), may result in contractures
- dermal
- subcutaneous
burn only affecting epidermis with inflammation of superficial dermis
first degree burn
sun burn
- burn affecting epidermis into dermis
- -Partial thickness – upper dermis
- -Full thickness – deeper dermis
- Blister formation
- -When fluid accumulates below BM
second degree burn
- burn causing destruction of epidermis and some / all dermis
- After epidermis, dermis, into subQ
third degree burn
burn:
- Painful, red but no blister formation
- Heals in 3 to 10 days and requires palliative (pain relieving) treatment only
first degree burns
- burns that involve the epidermis and upper portion of dermis resulting in dermal capillaries leaking
second degree burn - partial thickness
- Painful, red, with blister formation
- Maintain intact blisters for as long as possible
- Heal with supportive care in 1 to 2 weeks
second degree burn - partial thickness
interface between the dermis and epidermis
basal lamina/basement membrane
site of vesicle and blister formation, when the two layers become separated by fluid accumulation (serous, purulent, hemorrhagic)
beneath basement membrane
Involve the epidermis and dermis, but sensory nerves intact
second degree burn - full thickness
- Mottled pink, red, or waxy white regions, painful
- Blisters are flat and dry rather than bullous
- 1+ months to heal with scar formation; may have residual decreased sensation; risk of contractures
- Require hydration, supportive wound care, antibiotics
second degree burn - full thickness
- 1+ months to heal with scar formation; may have residual decreased sensation; risk of contractures
- Require hydration, supportive wound care, antibiotics
second degree burn - full thickness
Extend into the hypodermis, may involve muscle, bone, tendons
third degree burn
- Vary in color from white to yellow to black
- Hard, leathery, painless as sensory nerves are destroyed
third degree burn
- Require skin grafts as regenerative dermal elements have been destroyed
- Admission, antibiotics (IV), hydration, analgesia
- Disfiguring, extensive contractures likely
third degree burn
Effects of extensive burn injury to skin
- Initiates an acute phase response –> Fever, leukocytosis, anorexia, hypermetabolism, acute phase protein changes, cortisol elevation
- Risk of infection due to immune suppression, loss of epithelial barrier
- Dehydration and protein loss (epithelial barrier)
- Difficulty with temperature regulation (epithelial barrier loss)
- Organ dysfunction due to blood flow disruption (CV, renal, respiratory, GI)
causes of epidermal and dermal infections
- bacterias
- viruses
- fungi
Organisms grow within _____ and in ______ space of dermis
Organisms grow within epidermis and in interstitial space of dermis
effects of infectious skin disorders
- Consume nutrients, proteins
- May injure or destroy host tissue
- Cause inflammation (cardinal signs)
- May spread in skin (cellulitis) and along fascial planes (fasciitis)
classified as primary (starts as an infection, e.g., impetigo) or secondary (complication of another disorder, e.g., infected pressure ulcers)
bacterial infections
Characteristics of infection determined by:
- organism
- host immune incompetence
- tissue health
Bacterial infections are characterized by the presence of:
- Inflammatory signs
- crusting
In bacterial infections, these may be released, causing rash, skin injury
exotoxins or endotoxins
Where might bacterial infections occur
dermis only, localized, or widespread
examples of bacterial skin infections
- Impetigo
- epysipelas
- folliculitis
- carbuncles
- paronychia