anatomy integumentary system Flashcards
functions of the integumentary system
synthesize vitamin D
regulate body temperature
balance bodily fluids
sensations from processing environmental stimuli
excretion
how does the skin create physical barriers
from its many layers of cells and its continuity
how does the skin create chemical barriers
skin secretes natural antibiotics and most secretions have low pH
melanin
chemical pigment shield to protect against UV damage; made by melanocytes
epidermis
made of epithelial cells
get all nutrients from dermis
made from 4 types of epidermal cells
has 4-5 layers
what are the 4 types of epidermal cells
keratinocytes, melanocytes, dendritic, tactile
what are the 5 layers of the epidermis
stratum corneum, stratum lucidium, stratum granulosum, stratum spinosum, stratum basale
stratum corneum
20-30 layers of dead cells bond tightly to prevent water loss and protect layers below
stratum lucidium
only in thick skin, thin band of flat, dead keratinocytes just below stratum corneum
stratum granulosum
1-5 layers of cells; where cells fill with keratin; tough and water resistant
stratum spinosum
contains intermediate filaments that resist tension; dendritic cells are most abundant
stratum basale
single row of stem cells attached to the dermis where most new cells are mast, actively divide
dermis
made of mostly dense connective tissue
majority of our skin (where blood works get done)
embedded with blood vessels, glands, hair follicles, and nerves
2 layers
what are the 2 layers of dermis
papillary dermis and reticular dermis
what is papillary dermis
made of aerolar connective tissue
interwoven loosely with collagen, elastic fibers, and blood
contains dermal papillae
what is the reticular dermis
made of dense irregular connective tissue
houses network of blood vessels and thick bundles of collagen fibers that give dermis strength and resiliency
hypodermis
subcutaneous tissue
composed to adipose tissue
insulates against heat loss
energy storage
shock absorber
anchors skin to underlying structures (muscles)
hair
long filaments made of dead keratinocytes
3 layers
what are the three layers of hair
medulla
cortex
cuticle
medulla
central core made of soft keratin
cortex
bulky layer
cuticle
single layer of overlapping cells
when cuticle wears away at tip of hair shaft, split ends are created
hair follicles
tubular invaginations in the epidermis that hair grows out of
root hair plexus
nails
made of heavily keratinized cells
3 parts
rests of part of epidermis called nail bed
what are the 3 parts of nails
root
plate/body
free edge
nail matrix
where the nail grows
dermal papilla
has capillaries that supply hair with nutrients and signal growth
sweat glands
work to keep us from overheating
sebaceous gland
oily secretion
works to prevent water loss
lubricate/soften skin
antibacterial properties
2 types of glands
eccrine
apocrine
eccrine sweat gland
most abundant
extra in palms, forehead, soles of feet
sweat secretion
temperature control and antibacterial properties
apocrine sweat gland
lie deeper in dermis
larger
come during puberty
empty in the hair follicles around armpit and groin
potential sexual sweat glands
secrete proteins and sweat
2 types of modified apocrine glands
ceruminous and mammary
ceruminous gland
in ear cannal
make ear wax
mammary glands
secrete milk
