Please enable JavaScript.
Coggle requires JavaScript to display documents.
Jesus Carranza Per. 2 Integumentary System - Coggle Diagram
Jesus Carranza Per. 2 Integumentary System
Functions of the Skin
Protection
Chemical barrier
Skin secretes many chemicals
Acid mantle: low pH of skin retards bacterial multiplication
Melanin provides a chemical barrier against UV radiation damage
Physical barrier
Chemicals have limited penetration of skin
Flat, dead, keratinized cells of stratum corneum, surrounded by glycolipids
Blocks most water and water-soluble substances
Biological barrier
Epidermis contains phagocytic cells
Dermis contains macrophages
DNA can absorb harmful UV radiation, converting it to harmless heat
Body temperature regulation
Cool External Environment: dermal bloods constrict and skin temp drops to slow passive heat loss
Cool body down: dilation of dermal vessels can increase sweat gland activity
Normal Body Temp: Sweats glands produce unnoticeable sweat
Cutaneous sensations
Cutaneous sensory receptors
Exteroreceptors respond to stimuli outside body
Free nerve endings sense painful stimuli
Metabolic functions
Synthesize vitamin D
Chemicals from keratinocytes can disarm some carcinogens
Keratinocytes can activate some hormones
Makes collagenase
Blood reservoir
hold up to 5% of the body’s total blood volume
Skin vessels can constricted to shunt blood
Excretion
Secrete limited amounts of nitrogenous wastes
Layers of the Skin
Dermis (middle)
Reticular dermis (bottom)
Papillary dermis (top)
Hypodermis (bottom)
Adipose Tissue
Epidermis (top)
Stratum corneum (superficial layer) (horny layer)
Stratum lucidum (only thick skin) (clear layer)
Stratum granulosum (granular layer)
Stratum spinosum (prickly layer)
Stratum basale (basal layer)
Accessory organs
Hair
Regions
Medulla: central core of large cells and air spaces
Cortex: several layers of flattened cells surrounding medulla
Cuticle: outer layer consisting of overlapping layers of single cells
Follicle
Hair bulb: expanded area at deep end of follicle
Hair follicle receptor (or root hair plexus): sensory nerve endings that wrap around bulb
Epithelial root sheath: Derived from epidermis
Hair matrix: actively dividing area of bulb that produces hair cells
Arrector pili: small band of smooth muscle attached to follicle
• Hair papilla: Dermal tissue containing a knot of capillaries that supplies nutrients to growing hair
Functions: Warn of insects on skin, Hair on head guards against physical trauma, Protect from heat loss, Shield skin from sunlight
Nails
Nail root: contains nerves and blood vessels so that cell reproduction can occur
Eponychium (cuticle): nail fold that projects onto surface of nail body
Lunule (lunula): thickened nail matrix, appears white
Nail plate: visible part that lays on nail bed, made by Keratinisation
Free edge: end of the nail plate
Nail folds: skin folds that overlap border of nail
Nail matrix: thickened portion of bed responsible for nail growth
Nail bed: epidermis underneath keratinized nail plate
Glands
Oil (sebaceous): lubricate skin/hair, help prevent water loss, antibacterial properties, secrete sebum, everywhere except palms and soles
Sweat (sudoriferous)
Apocrine: Sexual scent, axillary and anogenital areas, ducts emptying into hair follicles
Ceruminous: lining of external ear canal; secrete cerumen (earwax)
Mammary: secrete milk
Eccrine (merocrine): Temperature control, antibacterial properties, on palms, soles, and forehead, empty from skin
Skin Cancer and ABCD rule
Squamous cell carcinoma (Second most common)
keratinocytes of stratum spinosum
Can metastasize
Melanoma (most dangerous)
ABCD
B: border irregularity
C: color
A: asymmetry
D: diameter
Cancer of melanocytes
Basal cell carcinoma (most common)
Least malignant
Stratum basale cells proliferate, invade dermis/hypodermis
Burns and rule of 9
Rules of 9
11 sections = 9% of body surface
genitals = 1%
Used to estimate volume of fluid loss
Degrees
2nd: Epidermal and upper dermal damage, Partial thickness
3rd: Entire thickness , Nerve endings destroyed
1st: Epidermal damage only