Chapter 3 - Integumentary System Flashcards
Other functions
- senses environment
- prevents fluid loss
- regulates body temperature
- excretes water
- produces vitamin D
Primary function
Protection -blocks injury and disease
Skin layers
1) Epidermis
2) Dermis
Epidermis
Stratified epithelial tissue
Keratin
Waterproof protein
Melanin
1) determines skin and hair color
2) absorbs, and is stimulated by UV rays
Carotene
Asians
Dermis
Collagen connective tissue - strength and elasticity
Dermis contents
- blood vessels
- nerves: touch, pain (nociceptors), temperature, pressure (baroreceptors)
- hair follicles
- glands: exocrine
- dermal elevations: grip, fingerprint
Exocrine glands
1) sweat
- water secretion (temperature regulation)
- water, salt, waste excretion (dilute urine)
2) sebaceous (oil)
- sebum secretion (hair and skin lubrication, bacterial inhibition)
- acne: blackhead (pimple)
Subcutaneous layer (“superficial fascia”)
Not a true skin layer
-adipose connective tissue
Appendages
1) Hair
2) Nails
Hair
1) Shaft: dead cells, above skin surface
2) follicle: root + tissue coverings, below skin surface
- manufactures keratin
- arrector pili muscle
Nails
1) keratin-based
2) protection, picking up small objects
3) lunula (moon)
Injections
- intradermal
- subcutaneous
- intramuscular
- intravenous
Skin grafts
1) types
2) thickness
3) instruments
Autograft
From patient
Allograft
From human donor
Xenograft
From another species
Skin substitutes
Another type of skin graft
Full-thickness
(FTSG)
Epidermis + dermis +/- some subcutaneous tissue
Split-thickness
(STSG)
Epidermis + 1/2 dermis
Skin graft instruments
1) dermatome
2) skin mesher
Surgical disorders
- Wound healing
- Burns
- Abnormalities
Wound healing (first intention)
Ideal, clean, most OR cases
1) inflammation phase
2) proliferation phase
3) maturation
Inflammation phase
- Clot forms
- Macrophages
- Fibroblasts arrive
Proliferation phase
- collagen secreted
- new capillary ingrowth
Maturation (differ action) phase
- collagen matures
- scar 70-80% strength
Wound healing (second intention)
1) wound failure or infection
2) granulation tissue forms
3) heals from bottom and edges
Wound healing (third intention)
For closure of second intention wounds
- debridement
- approximation of skin edges in 4-6 days
1st degree burns
Depth: epidermis
Appearance: red, dry
2nd degree burns
Depth: dermis
Appearance: blisters, wet
3rd degree burns
Depth: subcutaneous
Appearance: white, dry
4th degree burns
Depth: muscle/bone
Appearance: charred, dry
Abnormalities
1) acne vulgaris
2) neoplasms
- benign (warts, cysts, moles, keloids)
- malignant (basal and squamous cell carcinomas, melanomas)
3) cosmetic defects
4) decubitus ulcers
Diagnostic procedures
1) X-Ray
2) Biopsy
