Integumentary System
& Body Membranes

3.
4.
5.
2.
1.
Classify, compare the structure of and give examples of each type of body membrane
Describe the structure and function of the epidermis and dermis
List and briefly describe each accessory organ of the skin
List and discuss the three primary functions of the integumentary system
Classify burns and describe how to estimate the extent of a burn injury

:
Composed of epithelial tissue & underlying specialized connective tissue
…aka skin
… aka saliva
… aka snot :P
Contain no epithelial component
…line joint spaces between bones & bursae (sacs between moving body parts)
→smooth, thick
→secrete synovial fluid = for lubrication & reduce friction in joints

 Composition:
1. Thin layer of simple squamous epithelium
2. Thin layer of connective tissue -forms supportive basement membrane
 Function:
1.
body cavity lining and organ surface covering
(single membrane w/ it’s surfaces named separately)
* Parietal = name for body cavity lining
* Visceral = name for serous membrane covering organs
2. Produce watery fluid to reduce friction & lubricate any organ contact
 Examples:
1.
2.
Thoracic cavity= called Pleura
-so..Visceral Pleura=serous membranes covering the organs in thoracic cavity
-Pleurisy= inflamed Pleura; very painful friction of lungs rubbing chest wall
Abdominal cavity= called Peritoneum
-Peritonitis=inflamed serous membranes in abdominal cavity

 Location:
-line body surfaces opening directly to the exterior
-respiratory, digestive, urinary & reproductive tracts
 Composition:
* epithelium varies with location & function
Esophagus: stratified squamous epithelium –to protect from rough particles
-Lower Digestive Tract: simple columnar epithelium
 Function:
-produce thick, slimy material- aka mucus (provide moisture)
Mucocutaneous Junction =
-skin and mucous membranes meet (eyelids, nasal opening)
lacks accessory glands, need mucous glands for moisture
-common points of infection

*Primary organ of Integumentary System & largest body organ*
Structure:
→ Epidermis
→ Dermis
→ Subcutaneous
Appendages:
→ Hair
→ Receptors
→ Nails
→ Skin Glands
-Sudoriferous gland (sweat)
-Sebaceous gland (oil)
Function:
→ Protection
→ Temperature Regulation
→ Sense organ activity
Burns:
→Surface area estimation
→Classification

… outtermost layer
*Stratified Squamous Epithelium*
Tightly Packed
Arranged in layers {strata}
• Stratum Germinativum•
[innermost]
→ reproduces itself *self-repairing fxn!
→new cells move toward surface as they specialize with…
Keratin [ replaces cells cytoplasm]= tough, waterproof material for protection
• Stratum Corneum•
[outer layer of epidermis]
→ keratin filled, dead cells flake off
*Melanocytes deep in epidermisproduce melanin
→ absorb harmful UV & give skin darker pigment
→ with less melanin color can change w/ blood flow or oxygen level changes
Cyanosis: skin bluish gray with ↓blood O2 or ↓blood flow
* Specialized Junctions hold epidermis together and attach to dermis
Dermal-epidermal Junction= between thin epidermal layer and dermal layer below
Blisters: result of weakened or destroyed junctions

*Thicker layer
*mostly connective tissue
-cells scattered with fibers between
Upper Region:
-Dermal Papillae -parallel rows of bumps (important in junction)
-make finger/footprints unique
Deeper Dermis:
-Dense network of interlacing fibers
-Specialized nerve network for sensory info
-Layer of fat
→ insulation , provide stored energy, gives protection & shock absorption

Appendages
Follicles: required for growth
Lanugo =hair of newborn
Hair Papilla: where hair growth begins base of follicle
Arrector Pili: small smooth involuntary muscle contraction makes goose bumps (ex. in cold/ or fear )

Appendages

Appendages
-
-produced by cells of epidermis

Appendages
Most numerous produce sweat
Larger
(growth starts at pupberty)
Thicker secretions
Lubrication for hair and skin
Secretions increase during adolescence w/ hormone changes
Secretions decrease late adulthood –forming wrinkles and cracks in skin

1.
 “First line of defense”
 Keratin
 prevents movement across skin barrier, keeps bacteria out and keeps fluid in
 Melanin
 protects from UV
2.
 Sweat

Evaporation principle heat loss mechanism
3.
 Touch, pressure, pain & hot/cold

“Rule of Nines”
 Divides body into 11 areas-each 9%
 Recovery depends on total area involved and severity
Classification of Burns
1 st Degree (sunburn)
Minor discomfort, some reddening of skin, no blistering
2 nd Degree
Severe pain, deep epidermal layers & upper dermis injured, blisters, swelling, fluid loss, scaring common
3 rd degree
(full thickness burn)
Complete destruction of epidermis and dermis, tissue death into subcutaneous tissue (can go to muscle or even bone), pain insensitive-nerve endings injured, serious fluid loss & risk of infection