Integument & Wound Basics Flashcards
The integument
- Largest organ in body
- Physical barrier & sensory function
- Barrier to harmful chemicals, UV radiation, infection
- Temperature regulation & sweating
- Required for Vitamin D production
Epidermis
- Tough, leathery, most superficial surface
- Composed mainly of keratinocytes
- 0.05-1.5 mm thick, thickest on palms & soles
- Contains 5 layers representing different stages of cellular differentiation, bottom layer is only living layer
- Avascular, receives nutrients by diffusion through semi-permeable basement membrane
Basal Layer
- Deepest layer of epidermis, attached to dermis by thin basal membrane
- Contains single row of keratinocytes (live)
- Mitotic activity of keratinocytes confined to this later
- Epidermal turnover approximately 2-4 weeks
Keratinocytes
Produce keratin, a protective protein
Found in epidermis
Stratum corneum
- “Horny” layer
- Thickest and most superficial layer of epidermis (75%)
- Consists of dead keratinocytes
- Cells continuously abraded and replaced by cells below
- Friction or pressure will increase the thickness resulting in callus
Melanocytes
Produces pigment melanin
- Protects skin from UV
- Gives skin its color
- Found in epidermis
Merkel cells
- Specialized mechanoreceptors (light touch)
- Found in epidermis
Langerhan’s cells
- Found in deeper layers of epidermis
- Assist in fighting infection (attack & engulf foreign material) outside of normal immune cells
Hair follicles (soft keratin)
- Found everywhere but palms and soles
- Helps regulate body temp by trapping air
- Found in epidermis but extends into dermis
Sebaceous glands
- Each hair follicle contains one
- Secretes sebum: oily substance that lubricates skin and hair
- May also slow bacterial growth, reducing colonization
- Found in epidermis but extend into dermis
Sudoriferous glands
- Present everywhere except lips and ears
- Secrete sweat into ducts that lead to skin’s surface
- Evaporation of sweat helps cool the body
- Found in epidermis but extend into dermis
Nails (hard keratin)
- Found on dorsal tips of digits
- Protect terminal digit and assist with function
- Found in epidermis but extend into dermis
Functions of the epidermis
- Provides physical and chemical barrier
- Regulates fluid
- Provides light touch sensation
- Assists with thermoregulation
- Assists with excretion
- Assists with vitamin D production
- Contributes to cosmesis/appearance
Dermis
- 2 to 4 mm thick, fibrous part of skin
- Contains collagen and elastic fibers contained in an amorphous ground substance, nerve fibers, and nerve-end sensory organs
- Consists of two layers
- Highly vascular; capillaries provide color (pale pink to rosy red), superficial lymphatics (assist in returning H2O, proteins, and other substances from tissue to blood stream)
Papillary dermis
- Thin and superficial
- Loosely woven fibers embedded in gelatinous matrix (ground substance)
- Blisters occur here if friction between epidermis and dermis
Reticular dermis
- Deep layer of dermis
- Dense irregular arranged connective tissue
- Provide increased structural support to skin
Dermis should appear…
Shiny or moist if exposed due to high H2O content
Fibroblasts
- Found in dermis
- Produce collagen, elastin fibers, and ground substance
- Give dermis strength and flexibility
Macrophages & polymorphonuclear leukocytes (neutrophils)
- Found in dermis
- Help fight infection by engulfing harmful substances & releasing destructive enzymes
Mast cells
- Found in dermis
- Specialized secretory cells that produce chemical mediators of inflammation ie. histamine
- Attract other cells and cause vasodilation to fight infection or repair injury
Function of dermis
- Support and nourish epidermis
- House epidermal appendages (hair, glands)
- Assists with infection control
- Assists with thermoregulation
- Provides sensation
Subcutaneous tissue
- Supports the skin
- Composed of adipose tissue and fascia
- Deeper lymphatic vessels located here
Adipose tissue
- Highly vascular, loose connective tissue, stores fat for energy, insulation, protection (cushion over structures ie. Bony prominences)
- Healthy tissue is white to pale yellow & darker if dehydrated
Fascia
- Highly fibrous connective tissue
- Separates and surrounds structures, facilitates movements between adjacent structures (ie muscle tendon bone)
Muscle
- Regularly arranged fibers surrounded by fascia
- Rich vascular supply, red in color, bleeds easily
- Non-viable muscle will appear gray or black in color
Tendons
Regularly arranged fibers may be enclosed in fibrous sheath
Ligaments and joint capsules
- Dense connective tissue
- Ligaments: regularly arranged fibers
- Joint capsule: direction of fibers vary
- Healthy appearance is glistens (silky) white
- Non-viable, dry, leathery, dark, may be disconnected
Bone
- Shiny, smooth, milky white appearance, hard when probed
- Unhealthy: moth-eared, irregular surface, dark discoloration
Superficial wound
Affect only the epidermis
- Abrasion; top layer of integumentary is removed & dermis may be exposed
Partial-thickness wound
Involve epidermis and part of the dermis
- Severe sun burn with blistering and peeling
Full thickness wound
Effects go through the epidermis and dermis into the subcutaneous tissue layer
- Further categorized as subcutaneous or sub-dermal if tissues such as tendon, muscle or bone are involved
Describing a wound
- Location
- Size (length, width, depth)
- Undermining
- Tunneling
- Periwound area; erythema, callous, cliff, irregular edges, maceration
- Type of base; slough, granular, Escher
- Odor
- Exudate; type and amount
- Cause of wound; venous, arterial, diabetic, pressure
- Sensation
- Pulses
Location of wound
Use clock system
- 12 o’clock always up towards head
Undermining
Edges of wound separate from the underlying tissue, creating a pocket or cavity beneath wound surface
Tunneling
A narrow-channel like structure that extends from the surface of a wound into deeper tissues
Fistula
Surface to surface
Erythema
- Indicative of cellulitis, leads to…
- Heat
- Edema (turgor, swelling)
- Pain
- Loss of function
Clift
Cookie cutter, hole-punched appearance
Rolled edges
Epidermis rolls over wound bed, makes healing difficult
Maceration
Skin puffs out from too much fluid
- Similar to sitting in tub too long
Slough base
- Yellow, stringy, sticky
- Indicative of extra fibroblasts in wound
- Considered ok, don’t want it to stick around
Granular base
- Red, shiny, moist
- Want to see this, indicative of healing dermis
Eschar base
- Black, dead, dry tissue
- Don’t want to see this, needs to be removed for wound to heal
None exudate
Don’t want to see this, indicates dry wound tissues
Scant exudate
Wound tissues moist, no measurable exudate
Small exudate
Wound tissues wet, < 25% dressing shows drainage
Moderate exudate
Wound tissues saturated, 25-75% dressing shows drainage
Large exudate
Wound tissues bathed in fluid, drainage freely expressed, > 75% dressing shows drainage
Strike-through exudate
Drainage coming through the dressing
Serous exudate
Thin, watery, clear, indicates wound is doing well
Serosanguineous exudate
Thin, watery, pale red to pink in color
Sanguineous exudate
Thin, bright red in color
Purulent exudate
Thin or thick, opaque tan to yellow in color
Foul purulent exudate
Thick, opaque yellow to green with offensive odor
Contaminated
- All open wound are contaminated
- Bacteria present within the wound
- Bacteria are not multiplying
- There is steady state of replicating organisms that maintain a presence in the wound but do not cause delayed healing
Critically contaminated
- Bacterial burden in the wound bed is increasing
- Burden initiates the body’s immune response locally but not systemically (no fever)
- Wound is no longer healing at the expected rate
Infected
- Bacteria are present within the wound and are multiplying
- There is an associated host immune response locally and then systemically (fever present)
- Wound is painful and may increase in size
Bacterial biofilms
- Communities of bacteria and microorganism that adhere to solid surfaces
- Prevents normal wound healing process, sits on surface of wound, impaired migration and proliferation of keratinocytes
