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
