INTEGUMENTARY SYSTEM Flashcards
what is the cutaneous membrane composed of
- epidermis
2. dermis
what type of tissue is the epidermis
epithelium
what type of tissue is the dermis
connective tissue
what are the 2 components of integumentary system
- skin / cutaneous mem
2. accessory structures
what are 3 accessory structures
- exocrine glands
- hair
- nails
what are functions of the skin (6)
barrier protection thermoregulation sensation metabolic functions social functions
how does skin act as a barrier
prevents penetration from outside
prevents release from inside
what are exceptions
UV radiation (from outside) comes in
(helps with vitD production)
sweat (from inside) goes out
what is thermoregulation referring to
blood vessels constricts to retain heat
blood vessels dilate to release heat
what metabolic functions being referred to
- vitD synthesis
2. storage of en as subcutaneous fat
what are the 5 layers of epidermis from deep to superficial
- stratum basale (basal layer)
- stratum spinosum
- stratum granulosum
- stratum lucidum
- stratum corneum
what are characteristics of cells that can be found across 5 layers
keratinized
stratified
squamous
what do cells of epithelium produce
keratin
what is keratin
tough protein
STRATUM BASALE what does layer contain
stem cells
STRATUM BASALE what does layer produce
basil lamina
STRATUM BASALE what does basil lamina stick to
dermis (connective tissue)
STRATUM BASALE what do basil lamina + connective tissue form
basil mem
STRATUM BASALE what do stem cells give rise to when they multiply
keratinocytes
STRATUM BASALE what is the function of keratinocytes
- produce keratin
- new keratinocytes replace old keratinocytes
- phagocytize melanin granules to protect DNA from UV radiation
STRATUM BASALE where are merkel / tactile cells abundant
where skin has no hair
STRATUM BASALE what is function of merkel / tactile cells
touch sensation
STRATUM BASALE where are axons of merkel / tactile cells found
dermis
STRATUM BASALE what is function of melanocytes
- synthesize melanin pigment
2. transfer melanin granules to keratinocytes
STRATUM BASALE what do melanocytes have
long + slender processes that insert bw keratinocytes
STRATUM BASALE what does number of melanocytes depend on
region of body
STRATUM SPINOSUM what 2 epithelium cells does layer contain
- keratinocytes
2. langerhans / dendritic cells
STRATUM SPINOSUM what do keratinocytes contain
tono filaments
STRATUM SPINOSUM what do tono filaments cause
keratinocytes flatten
keratinocytes reach for other keratinocytes
STRATUM SPINOSUM what is function of desmosomes
attach keratinocytes
STRATUM SPINOSUM what are langerhans
type of macrophage originating from bone marrow that migrate to epidermis
STRATUM SPINOSUM what is function of langerhans
phagocytosis
capture pathogens
offer pathogens to immune system
STRATUM SPINOSUM where can langerhans be found
epidermis of
- oral cavity
- esophagus
- anal cavity
- vaginal cavity
STRATUM GRANULOSUM what is produced in layer
keratohyalin granules
STRATUM GRANULOSUM what is stratum granulosum
2-5 layers of flat keratinocytes
STRATUM GRANULOSUM what do keratinocytes secrete
lipid filled vesicles
STRATUM GRANULOSUM what do vesicles fill
spaces bw the keratinocytes
STRATUM GRANULOSUM what is the purpose of filling spaces
act as sealant
STRATUM GRANULOSUM what does sealant cause
keratinocyte death in layers above
nutrients not diffusing
STRATUM GRANULOSUM what is a callus made of
excess keratin
excess lipid
STRATUM GRANULOSUM where do calluses form
in areas of high mechanical abrasion
STATUM LUCIDUM what does layer contain
- large amounts of keratin
2. thickened plasma
STATUM LUCIDUM what are cells lacking
- nucleus
2. other organelles
STATUM LUCIDUM what kind of skin is layer found in
- palmer
2. plantar
STRATUM CONEUM what does layer contain
layers of flattened + dead keratinocytes
STRATUM CONEUM what is dander
keratinocytes that get shed
STRATUM CONEUM what does layer provide
protection against
- abrasion
- microbial invasion
what do keratinocytes do at night
mitosis
what do keratinocytes do during day
shed
what can accelerate mitosis / cell division
- injury
2. mechanical stress
what does accelerated mitosis result in
more keratinocytes
more keratin
more calluses
what kind of interface is epidermal -dermal
peak + valley
what does peak + valley interface allow
tight bond
where is dermal papilla tall
in sensitive areas
to allow nerve fibres+ capillaries to reach surface
where is interface unique to each person
fingers
what are 2 layers of dermis
- papillary
2. reticular
what does papillary layer contain
- areolar loose CT
- nerve endings for touch, temp, pain
- capillaries (WBC)
what does papillary layer do
increase area of contact w dermis
what does reticular layer contain
- dense irregular CT
- collagen fibers
- elastic fibers
what do fibres provide
extensibility + elasticity to skin
what is bw the collagen + elastic fibres (6)
- blood vessels
- nerves
- lymphatics
- hair follicles
- glands
- adipocytes