ch 5 - integumentary system Flashcards
2 parts of the integumentary system
- cutaneous membrane (skin) - epidermis and dermis
- accessory structures: hair, hair follicle, nails, glands
3 layers of the skin
epidermis
dermis
hypodermis
integument functions (4)
- protection - acts as physical and chemical barrier
- excretion - removes wastes through sweat
- thermoregulation
- melanin production
epidermis
top layer of skin made of stratified squamous epithelium tissue
2 types of skin in epidermis
thick and thin
thin skin
has 4 layers in the epidermis, covers most of the body
thick skin
has 5 layers in the epidermis, found on palms of hands + soles of feet
keratin
double protein that makes hair and nails
keratin function
protects tissue of skin; made of tough protein fiber
epidermis sublayers
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stratum basale
stratum spinosum
stratum granulosum
stratum lucidum
stratum corneum
stratum basale
- deepest layer where cell division takes place
- attachment to basement membrane
- contains basal cells, melanocytes and tactile cells
stratum spinosum
-2nd deepest layer of epidermis
-has 8-10 layers of keratinocytes bound by desmosomes and contains langerhans cells
stratum granulosum
-3-5 layers of flattened dying keratinocytes that produce keratin
stratum lucidium
- appears as glassy layer in thick skin only
- 4-6 layers of flattened dead keratinocytes,
stratum corneum
top layer
- has dead cells continually shedding and being replaced
- water resistant, not waterproof
types of water loss from skin (2)
- insensible perspiration: evaporative water loss, cant be seen or felt
- sensible perspiration: sweating
dermis
deeper layer of skin located under epidermis
- made of connective tissue with collagen and elastic fibers
2 layers of the dermis
papillary and reticular
papillary layer
top layer of dermis that is thinner and made of loose areolar tissue
papillary layer function
nourishes and supports epidermis
reticular layer
deeper layer of dermis that consists of dense irregular connective tissue, rich in collagen and elastic fibers