Integumentary System Flashcards
function:
- PROTECTION
- SENSATION
- HOMEOSTASIS
- SECRETION
Thermoregulation
Fluid/Electrolyte balance
• HOMEOSTASIS
layers of the skin
epidermis
dermis
HYPODERMIS/SQ FAT
Stratified squamous
keratinizing epithelium
epidermis
Dense irregular CT
dermis
Modified loose CT
HYPODERMIS/SQ FAT
COMPONENTS OF SKIN
epithelium
connective tissue
nervous, muscle tissue
- Epidermis
- Epidermal appendages
- Endothelium of blood vessels
epithelium
connective tissue
dermis
• Keratin-producing • Undergo differentiation • End-result: tough waterproof layer (=stratum corneum)
KERATINOCYTES
important layers
STRATUM CORNEUM
STRATUM LUCIDUM
STRATUM GRANULOSUM
STRATUM SPINOSUM
STRATUM BASALE
cause skin to regenerate
stratum basale
• Thin, lightly staining refractile layer • Seen only in thick skin • 4-6 rows of very flat cells • Rarely see nuclei • Cells are essentially dead
STRATUM LUCIDUM
- INTERCELLULAR LIPID
- THICKENED PLASMA MEMBRANE (envelope proteins)
- KERATIN BUNDLES + MATRIX
- Impermeability to water
- Mechanical barrier
STRATUM CORNEUM
• Flattening • Filling with keratin • Thickening of membrane • Waterproofing with intercellular lipid • Losing nuclei/organelles
KERATINIZATION
• 1000-2000 cells/sq mm • 1 melanocyte : 30 keratinocytes • Dendritic cell in basal layer • Melanin-producing • Protection against UV
melanocyte
• Fine brush-like in Papillary dermis • Coarse, fragmented in Reticular dermis • Bundles are oriented differently
- Mechanical strength
- Skin lines
ELASTIC FIBERS
SKIN LINES
langer
kraissl
borges and alexander
• Cadaveric study
• Opening of skin lines between
puncture pts
• Tension determined by elastic fibers
langer
- Wrinkle lines
* Follows musculo-tendinous action
kraissl
- Relaxed skin tension lines
* Creases formed by skin pinching
borges and alexander
what causes pain?
free nerve endings
• Small cocoon-like • In dermal papillae, oriented perp. To surf • Lips, fingertips/toes • Fxn: light touch
MEISSNER CORPUSCLE
- Onion-shaped structures
- Deep dermis/hypod
- Fingertips/jts
- Fxn: pressure/vibration
PACINIAN CORPUSCLE
- HAIR
- NAIL
- Hard keratin (vs. soft keratin of epidermis)
MODIFIED EPIDERMAL STRUCTURES
- Sebaceous
- Eccrine
- Apocrine
GLANDS
Hair follicle
Arrector pili
Sebaceous gland
*Apocrine gland
PILOSEBACEOUS UNIT
types of hair
TERMINAL HAIR
VELLUS HAIR
TERMINAL HAIR
• Scalp, eyebrows/lashes,
axillae/pubis
• Larger, coarser, deeper root
VELLUS HAIR
- Rest of body
* Thin, lightly pigmented
• Simple branched acinar gland • Sebum - lubricant • Holocrine secretion • Not found in palms, soles and glans
sebaceous gland
- Simple coiled tubular gland
- Opens into infundibulum
- Scent hormones
- In axillae, areola, genital area
apocrine
• Simple coiled tubular • Opens directly on skin surface • Except in lips, ext. genitalia; Most numerous in palms, soles, forehead, axilla • Thermoregulation
eccrine
Anterior aspect of the head from the
forehead to the chin and from one earto the
other
▪ Providesour identity as an individual human
▪ Basic shape is determined by the underlying
bones
face
Facial lacerations tend to
gape –becausethe
face has no deep fascia and the
subcutaneous tissue between the cutaneous
attachments of the muscles is loose
Looseness of the subcutaneous tissue
enables fluid and blood to accumulate
following bruising
Facial lacerations
