Integumentary System Flashcards
What are the functions of the integumentary system?
Protection Blood reservoir Temperature regulation Sensation Chemical synthesis Excretion & absorption
What does the integumentary system consist of?
Skin Hair Nails Glands Sensory receptors
Specialized functions of integumentary system: protection
Keratinization: protects from water loss
Immune function: keratinocytes/Langerhan’s cell and sebum
Specialized function of integumentary system: sensory function
Sensory function: ability to detect environmental changes
Exteroceptors: sensory receptors located in skin to respond to tactile sensations and temperature changes
Specialized functions of integumentary system
Blood reservoir: dermis
Excretion & absorption (negligible function)
Specialized functions of integumentary system: chemical synthesis
Melanin: pigmentation, protective role against UV Rays
Keratin: waterproofs
Vitamin D: sunlight, important in bone health
Special owe functions of integumentary system: thermoregulation
Importance: homeostasis, 98.6 in order for cells to function properly
Radiation: transfer of heat through space from one object to another (heat from sun)
Conduction: Heat gain/loss through direct contact (ice pack, sitting on cold bleachers)
Convection: Heat gain/loss through indirect contact (wind chill/whirlpool)
Evaporation: Heat loss, cooling by converting liquid to vapor (sweating)
Malfunctions in temperature regulation
Hypothermia: too little heat
Heat loss > Heat gain
Hyperthermia: too much heat
Heat loss < Heat gain
Hair structure
Primary components:
Shaft: what you see, dead keratinized tissue
Root
Accessory structure: Follicle Arrector pili: smooth muscle, when contracted hair stands up Bulb Melanocytes
Hair color
Pigmented by melanin
Genetically determined:
Brown/black
Yellow brown/red
Gray hair- lack of melanin
Hair growth
Hair follicle
Cycles: fast & slow, follicles die and hair falls out
Factors:
Nutrition
Hormones- androgens (sex hormones)
Stressors
Skin
Dermatology: skin doctor
3 layers-
Epidermis: outer layer
Dermis: second layer
Hypodermis: third layer (subcutaneous layer, superficial fascia)
Accessory skin structure
Hair
Glands
Nails
Skin color: physiological factors
Albinism: deficiency/absence of pigment in hair, skin, eyes
Respiratory/vascular disease: can decrease quantity of oxygen in blood, resulting in a blush tint to the skin called cyanosis
Skin color: environmental factors
Sun exposure influences melanin production
Skin color: genetic factors
Melanin production determined by genetic factors
Skin- aging effects
Skin more easily damaged
Decreased ability to regulate temperature
Oil glands decrease; skin becomes drier
Functioning melanocytes decrease or increase as with age spots
Sunlight/environment/smoking ages skin more rapidly
Skin-burns
Homeostatic imbalance
First degree: only epidermis is damaged (sunburn, iron, does not create an open wound)
Second degree: epidermis and dermis are damaged, leaves scar, longer healing time
Third degree: epidermis, dermis, and hypodermis are damaged, lost protective function, scarred skin, may need skin grafts
Epidermis
Avascular
Stratified epithelial tissue
5 epithelial strata
4 cell types
Epidermis cell types
Keratinocytes: produce keratin for strength
Melanocytes: contribute to skin color
Langerhan’s cells: part of immune system
Merkel’s cells: detect light touch & pressure
Dermis- functions
Binds
Sensory
Nourishes (vascular)
Toughness & elasticity
Dermis characteristics
Structural strength
Histologic features-
Reticular: connective tissue (elastic & collagen fibers) gives skin elasticity, houses accessory organs
Papillary: interlocking layer, dense irregular connective tissue
*fingerprints: arrangement of papilla
Hypodermis
Skin rests on this, but not a part of
Histologic features:
Adipose (thermoregulator)
Areolar connective tissue
Also called:
Subcutaneous tissue
Superficial fascia
Epithelial strata
- ) stratum basale: basement membrane, cells divide by mitosis & some of the newly formed cells become the cells of the more superficial strata
- ) stratum spinosum: not a reproducing layer, contains keratinocytes, keratin fibers lamellar bodies accumulate
- ) stratum granulosm: layer of dead cells, keratohyalin & a hard protein envelope form, lamellar bodies release lipids, cells die
- ) stratum lucidum: clear, dead cells containing dispersed keratohyalin
- ) stratum corneum: layer you see, dead cells with a hard protein envelope, the cells contain keratin & are surrounded by lipids
Thick skin
Has all 5 epithelial strata
Found in areas subject to pressure or friction (palms of hands, soles of feet, fingertips)
Thin skin
Missing the stratum lucidum
More flexible than thick skin
Hairy
Covers rest of body
Sebaceous glands
Secrets sebum
Exocrine gland
Share a duct with hair
Sebum moistens skin, aids epidermis in waterproofing, bactericide (prevents bacteria from entering skin)
Sudoriferous glands
Merocrine or eccrine: most abundant, most of dermal tissue, secretes water, electrolytes, salty sweat, helps with temperature regulation
Apocrine: axillal and anogenital, oily sweat, gives body odor, stains clothes, excreted in stressful times, no temperature regulation.
Specialized glands-
Ceruminous: only in ears; wax
Mammary: in breast tissue; holocrine gland
Nail- composition
Hard, keratinized epithelial tissue
Nail- structural components
Nail body: rests on nail bed Nail bed Eponychium: cutical, holds nail in place & protects living/growing part of nail Nail matrix: living part of nail Free border Hidden border: root
Nail- function
Protect vulnerable surfaces
Help pick up objects
