Download Integumentary system

Integumentary System
Membrane Classification
• Epithelial
membranes
– cutaneous
– mucous
– serous
• Connective tissue
membranes
– synovial
Cutaneous Membrane - skin
Functions?
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Protection
Excretion
Maintenance of body temperature
Synthesis
Storage
Detection of sensation
Thick vs. Thin
Skin Structure
• Epidermis – outer layer
– Stratified squamous
epithelium
– Often keratinized
(hardened by keratin)
• Dermis
– Dense connective
tissue
Epidermal strata
Epidermal strata
• Stratum basale (germinativum)
– cells dividing
– next to dermis
– melanocytes - umbrella for DNA
Epidermal strata
• Stratum spinosum
– spiny layer
• Stratum granulosum
– grainy layer
– still living
– produce keratin
• Stratum lucidum
– thick skin
– dead
Epidermal strata
• Stratum corneum
– keratinized “shinglelike” cells
– water resistant
– 20-30 cell layers
thick
– 25-45 days
What happens to the epidermis when…
• You have a blister?
• You take a bath?
What factors contribute to skin color?
• Carotene
• Blood flow/hemoglobin
• Melanin
Dermis consists of connective tissue
Dermis has 2 layers
– Papillary layer
• Projections called dermal papillae
• Pain receptors
• Capillary loops
– Reticular layer
• Blood vessels
• Glands
• Nerve receptors
Dermal papillae
Hypodermis
• Consists of areolar and adipose tissue
• Not really part of the integumentary
system
• Target site for subcutaneous injection
Glands in the skin
• Sebaceous glands
– Produce oil (sebum)
• Lubricant for skin/hair
• Kills bacteria
– Most with ducts that empty into hair follicles
– Glands are activated at puberty
Sweat (sudoriferous) glands
• Apocrine sweat glands
– Armpits
– Produce a stick, cloudy, and odorous
secretion
– Begin secreting at puberty
Eccrine sweat glands
• Eccrine
– Found all over body
– Open via duct to pore on skin surface
– Not odorous, inhibit bacterial growth
eccrine
eccrine
eccrine
Sweat
• Composition
– Mostly water
– Some metabolic waste
– Fatty acids and proteins (apocrine only)
• Function
– Helps dissipate excess heat
– Excretes waste products
– Acidic nature inhibits bacteria growth
• Odor is from associated bacteria
Hair
• produced by hair
bulb
• hard keratinized
cells
• color produced by
melanocytes
Hair
Hair
• arrector pili-muscle
• shape determines
texture
– oval: wavy
– flat: curly
– round: straight
Integumentary Repair
Burns
• Tissue damage and cell death
– heat
– electricity
– UV radiation
– chemicals
• Associated dangers
– dehydration
– electrolyte imbalance
– circulatory shock
Burns
• First-degree burns
– Only epidermis is damaged
– Skin is red and swollen
• Second degree burns
– Epidermis and upper dermis are damaged
– Skin is red with blisters
• Third-degree burns
– Destroys entire skin layer
– Burn is gray-white or black