integumentary system: covers body & consists of skin & accessary tissues
integument: skin
cutaneous membrane: barrier to the outside world
dermatology: study of skin
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Terms in this set (48)
stratum basale: single layer of cuboidal to low columnar cells
3 types:
1. keratinocytes:
found in all layers
synthesizes keratin
keratin: protein that strengthens epidermis
2. melanocytes:
scattered among keratinocytes in stratum basale
produce & store pigment (melanin) in response to UV light
transfer pigment granules (melanosomes) into keratinocytes
melanosomes: shield nuclear DNA from UV radiation
3. tactile cells:
merkel cells
when compressed, release chemicals, stimulate sensory nerve endings
1. nevus: localized overgrowth of melanocytes 2. freckles: localized areas of increased melanocyte activity 3. hemangiomas: skin discoloration due to benign blood vessel tumor 4. friction ridges: large folds & valleys of dermis & epidermiswhat are the 4 skin markings? explain each.3 types: 1. UVA 2. UVB 3. UVC SPF: sun protection factor sunless tanners: create tanned skin w/o UV light exposurewhat 3 types of radiation does the sun generate? what does SPF mean? what are sunless tanners?dermis: deep to the epidermis 2 layers: 1. papillary layer 2. reticular layerexplain the dermis. what are the 2 layers of the dermis?papillary layer: superficial region of dermis, deep to epidermis contains: areolar connective tissue dermal papillae: projections of dermis epidermal ridges: increase area of contact between layers reticular layer: deeper, major portion of dermis contains: dense irregular CTpapillary layer (explain. what tissue is it composed of? 2 components) vs reticular layer (explain. what type of tissue is it composed of?).2 fibers: 1. collagen fibers 2. elastic fibers bundles function: resist stress during routine movement lines of cleavage: tension lines skin stretches beyond capabilities cause: striae: stretch marksIn the dermis, what 2 fibers are oriented in parallel bundles at specific location? bundles function. what are lines of cleavage? what happens if skin is stretched beyond its capabilities?tattoos: permanent images produced on integument dye injected into dermisexplain tattoos (2).subcutaneous layer: not part of integument tissue: areolar & adipose CT function: protection, energy storage, & insulationexplain the subcutaneous layer. what tissue does it compose of? function.functions: 1. protection: protects body from injury, harmful substances, microbes, extreme temp., & UV radiation 2. prevention of water loss/gain: epidermis is water resistant, not waterproof 3. metabolic regulation: formation of vitamin D3: a precursor to calcitriol calcitriol: increases absorption of calcium & phosphate from diet; regulates blood calcium levels 4. secretion & absorption: waste products secreted onto skin surface during sweating selectively permeable transdermal administration 5. immune function: dendritic cells in epidermis & dermis capable of initiating immune response 6. temperature regulation: vasoconstriction: conserve heat vasodilation: release heat 7. sensory reception: innervation: allows for detection of stimuliwhat are the 7 functions of the integument? explain each.scale-like modifications of stratum corneum free edge: no underlying capillaries nail body: underlying capillaries nail root: part embedded in skin nail plate: consists of the free edge, nail body, and nail root nail bed: layer of living epidermis covered by nail body nail matrix: actively growing part of nail at proximal end of nail body lunula: whitish semilunar area on proximal end of nail body nail folds: folds of skin overlapping nail eponychium: narrow band of epidermis from margin of nail wall onto nail body hyponychium: thickened stratum corneum over which free nail edge projectswhat is the structure of nails like? explain a free edge. what's a nail body? explain the nail root. what's the nail plate? explain the nail bed. what is the nail matrix? what's the lunula? what are nail folds? explain the eponychium (cuticle). what's the hyponychium?hair: found almost everywhere on the body 3 types hair: 1. lanugo: fine, unpigmented, downy hair 2. vellus: fine hair location: upper & lower limbs 3. terminal hair: coarser, pigmented, longer location: scalp, eyebrows, eyelashes, men's beardsexplain hair. lanugo (explain) vs vellus (explain & location) vs terminal hair (explain & location).3 zones: 1. hair bulb: swelling @ base where hair originates in dermis hair papilla: composed of CT 2. root: zone of hair from bulb to skin surface 3. shaft: portion of hair beyond skin surfacewhat are the 3 zones along the length of a hair?hair matrix: structure @ base of hair bulb function: produce new cells, gradually pushed towards surface medulla: remnant of matrix cortex: flattened cells closer to outer hair surface cuticle: single cell layer around cortex hair follicle: oblique tube surrounding hair root CT root sheath: outer, originating in dermis epithelial tissue root sheath: inner, originating from epidermis arrector pili: thin ribbons of smooth muscle function: elevates hair w/ contraction, "goosebumps"hair matrix (explain & function). explain the medulla. explain the cortex. explain the cuticle. explain the hair follicle (CT root sheath & epithelial tissue root sheath). explain the arrector pili (function).6 functions hair: 1. protection 2. facial expression 3. heat retention 4. sensory reception 5. visual identification 6. chemical signal dispersalwhat are the 6 functions of hair?hair color: synthesis of melanin in matrix adjacent to hair papillae hair growth: 1. anagen: active phase 2. catagen: brief regression period 3. telogen: resting phaseexplain hair color. what are the 3 steps of hair growth?hair loss: normally 10-100 hairs lost per day alopecia: thinning of hair diffuse hair loss: hair shed from all parts of scalp male pattern baldness: loss of hair first from only crown region of scalp hirsutism: excessive male pattern hairinessexplain hair loss. what is alopecia? explain diffused hair loss. what is male pattern baldness? explain hirsutism.sweat glands: 1. merocrine 2. apocrinewhat are the 2 types of sweat glands?merocrine sweat glands: most numerous & widely distributed function: discharge secretions onto skin surface secretes: sweat: composed of 99% water & 1% other chemicals major role in: thermoregulationexplain merocrine sweat glands (eccrine). function. what does it secrete? explain ^. what does it play a major role in?apocrine sweat glands: coiled, tubular glands. function: discharge secretions into hair follicles located axillae, around nipples, in pubic & anal regionexplain apocrine sweat glands. function.sebaceous glands: holocrine glands function: produce oily secretion, sebumexplain sebaceous glands. function.2 other apocrine glands: 1. ceruminous glands: modified apocrine sweat glands location: external ear canal function: secretes waterproof earwax, cerumen 2. mammary glands: modified apocrine sweat glands location: breasts function: produce milkwhat are the 2 other apocrine glands? explain each. location. function.tissue repaired: 1. regeneration: replacement of damaged/dead cells w/ same cell type 2. fibrosis: gap filled w/ scar tissuewhat are the 2 ways tissue is repaired? explain each.wound healing: 1. cut blood vessels bleed into wound 2. blood clot forms & leukocytes clean wound 3. blood vessels re-grow & granulation tissue forms 4. epithelium regenerates & CT fibrosis occurswhat are the 4 steps of would healing?major cause accidental death: heat, radiation, chemicals, sunlight, electrical shock first degree burns: involve only epidermis second degree burns: involve epidermis & part of dermiswhat is the major cause of accidental death? (5) explain first degree burns. explain second degree burns.third degree burns: involve epidermis, dermis, & subcutaneous layer requires: skin graft rule of nines: burn severity measured byexplain third degree burns. what do they require? how can burn severity be measured by?burn treatment 1. manage fluid loss 2. relieve swelling 3. manage pain 4. remove dead tissue 5. control infection 6. increase calorie intakewhat are 6 ways you can treat burns?skin change from aging: 1. reduced # & activity of stem cells 2. UV radiation: damaged DNA in epidermal cells 3. skin cancer: most common type of cancerhow does skin change with aging? (3)nervous system: communication & control system. 3 functions: 1. collect information: receptors detect stimuli & send sensory signals to spinal cord & brain 2. processes & evaluate information: brain & spinal cord determine response to sensory input 3. initiate response to information: brain & spinal send motor output via nerves to effectorsexplain the nervous system. what are the 3 functions of the nervous system? explain each.central nervous system (CNS): brain & spinal cord peripheral nervous system (PNS): nerves & gangliacentral nervous system vs peripheral nervous system. what does each contain.sensory nervous system: afferent nervous system function: receives sensory information from receptors & transmits it to CNS somatic sensory system: detects stimuli we consciously perceive visceral sensory system: detects stimuli we typically do not perceive motor nervous system: efferent nervous system function: initiates motor output & transmits it from CNS to effectors somatic motor system: sends voluntary signals to skeletal muscles autonomic motor system: sends involuntary commands to heart, smooth muscle, & glands sympathetic: "fight or flight" parasympathetic: "rest & digest"what is the sensory nervous system? function. somatic sensory system vs visceral sensory system. explain each. what is the motor nervous system? function. somatic motor system vs autonomic motor system. explain each. sympathetic vs parasympathetic.nerve: a bundle of parallel axons in the PNS 3 CT wrappings: 1. epineurium: encloses entire nerve 2. perineurium: wraps fascicle (bundle of axons in nerve) 3. endoneurium: wraps an individual axon function: separates & electrically insulates each axon nerves are vascularized: blood vessels branch through epineurium & perineurium to become capillaries which allow for exchange between axons & bloodwhat is a nerve? what are the 3 CT wrappings around a nerve? explain each. (#3 state function too). are nerves vascularized? explain.cranial nerves: extend from brain spinal nerves: extend from spinal cord sensory nerves: contain sensory neurons sending signals to CNS motor nerves: contain motor neurons sending signals from CNS mixed nerves: contain both sensory & motor neurons ganglion: a cluster of neuron cell bodies in the PNScranial nerves vs spinal nerves. explain each. sensory nerves vs motor nerves vs mixed nerves. explain each. what is a ganglion?5 neuron characteristics: 1. excitability: responsiveness to a stimulus 2. conductivity: ability to propagate electrical signal 3. secretion: release of neurotransmitter in response to conductive activity 4. extreme longevity: cell can live throughout person's lifetime 5. amitotic: after fatal development, mitotic activity is lost in most neuronswhat are the 5 neuron characteristics? explain each.cell body: plasma membrane encloses cytoplasm (perikaryon) function: initiates some graded potentials, receives others from dendrites; conducts these potentials to axon contains: chromatophilic substance which are nissl bodies made of ribosomes dendrites: short, unmyelinated processes branching off cell body function: receive input & transfer it to cell body axon: long process emanating from cell body axon hillock: attached to cell body axoplasm: cytoplasm in axon axolemma: membrane in axon axon collaterals: the axon splits into branches telodendria: axon terminals synaptic knobs: tips of telodendria synaptic vesicles: contain the neurotransmitter function: conduct action potentials & then release neurotransmitter at synaptic knobs cytoskeleton: composed of microfilaments, intermediate filaments, microtubules neurofilaments: intermediate filaments neurofibrils: bundles are formed function: provide tensile strengthwhat is the cell body? (explain, function, what does it contain?) explain dendrites. (function). what is an axon? (explain, axon hillock, axoplasm vs axolemma, axon collaterals, telodendria, synaptic knobs, synaptic vesicles, function). what is the cytoskeleton? (explain, neurofilaments, neurofibrils & neurofibrils function)anterograde transport: from cell body function: moves newly synthesized material toward synaptic knobs retrograde transport: to cell body function: moves used materials from axon for breakdown & recycling in soma occur: 1. fast axonal transport 2. slow axonal transportanterograde transport vs retrograde transport. (explain, function). how can these occur? (2)fast axonal transport: occurs at about 400 mm per day transport: anterograde / retrograde motion possible slow axonal transport: occurs at about 0.1 to 3 mm per day result: from flow of axoplasm substances move: from cell body toward knobsfast axonal transport (explain, what kind of transport can occur?) vs slow axonal transport (explain, resulted from, where do substances move to?).structural classification: # processes coming off soma multipolar neurons: many dendrites, one axon bipolar neurons: one dendrite & one axon unipolar neurons: one process extends from cell body peripheral process: splits into several receptive dendrites central process: leads to synaptic knobs in CNS anaxonic neurons: have dendrites but no axonswhat is structural classification? multipolar neurons. explain. bipolar neurons. explain. unipolar neurons. explain. splits into 2 processes. explain each. anaxonic neurons. explain.functional classification: direction they propagate action potentials sensory neurons: conduct input from somatic & visceral receptors to CNS motor neurons: conduct output from CNS to somatic & visceral effectors interneurons: receive, process, & integrate information from many other neurons communication: between sensory & motor neuronswhat is functional classification? sensory neurons. function. motor neurons. function. interneurons. function. communication.synapse: place where a neuron connects to another neuron or an effector 2 types: 1. electrical synapse: presynaptic & postsynaptic neurons bound together by gap junctions fast: no synaptic delay in passing electrical signal 2. chemical synapse presynaptic neurons: axon terminal produces signal postsynaptic neurons: receive signal synaptic cleft: small fluid-filled gap between the 2 neurons events of synaptic communication: 1. neurotransmitter molecules released from vesicles of synaptic knob into cleft 2. neurotransmitter diffuses across cleft & binds to postsynaptic receptors 3. binding of neurotransmitter to receptor initiates postsynaptic potential synaptic delay: time it takes for all of these eventswhat is a synapse? electrical synapse. (explain, fast or slow). chemical synapse. (presynaptic neurons, postsynaptic neurons, synaptic cleft, 3 events of synaptic communication, synaptic delay).