Lesson 2: Integumentary System Flashcards
consists of the skin, hair, glands, and nails
integumentary system
functions of integumentary system
- protection
- sensation
- temperature regulation
- vitamin d production
- excretion
three major regions of skin
- epidermis
- dermis
- hypodermis (subcutaneous tissue)
outermost region (superficial)
epidermis
resists abrasion, reduce water loss
epidermis
bulk of skin
dermis
structural strength, where leather is produced (in animals)
dermis
deepest region of the skin
hypodermis
not really part of the skin
hypodermis
connects skin to muscle/bone
hypodermis
epidermis is composed of _ _ _ epithelium
keratinized stratified squamous
epidermis cell types
- keratinocytes
- melanocytes
- Merkel cells
- Langerhans’ cells
most abundant cell type, gives skin its protective properties
keratinocytes
keratinocytes produce _ _ _
fibrous protein keratin
melanocytes produce brown pigment called _
melanin
found in the deepest layers of the epidermis
melanocytes
langerhan’s cells are epidermal macrophages which helps _ _ _ _
activate the immune system
touch receptors in association with sensory nerve endings
merkel cells
basal layer
stratum basale
desmosomes and hemidesmosomes provide _ _
structural strength
deepest epidermal layer firmly attached to the dermis
stratum basale
consists of a single row of the youngest keratinocytes
stratum basale
cells in the stratum basale undergo mitotic division every
19 days
-% in the stratum basale are
melanocytes
one layer of _ are found in stratum basale
keratinocyte
melanin in stratum basale are given to _ _
stratum spinosum
melanin granules and langerhans’ cells are abundant in this layer
stratum spinosum
changes in keratinocyte appearance occurs here
stratum granulosum
in stratum granulosum, _ & _ bodies accumulate
keratohyaline, lamellated
cells start to die at stratum
granulosum
thin, transparent band
stratum lucidum
consists of flat, dead keratinocytes
stratum lucidum
layer present only in thick skin
stratum lucidum
outermost layer of keratinized cells
stratum corneum
stratum corneum accounts for _ _ of epidermal thickness (20-30 dead cell layers thick)
three quarter
million cells at stratum corneum rub off everyday, totally new every - days
25-45
renders body relatively insensitive to bio, chemi, and physi assaults
stratum corneum
hair is only found in _ _
thin skin
stratum lucidum is usually absent at _ skin
thin
has all five epithelial strata
thick skin
melanocytes produce
melanin
melanocytes produce melanin inside
melanosomes
size & distribution of melanosomes determine _ _
skin color
melanin is influenced by _ light and _
UV, hormones
red skin color (increased blood flow)
erythema
bluish, decreased oxygen in blood
cyanosis
plant pigment, skin=yellowish
carotene
second major skin region containing strong, flexible connective tissue
dermis
in dermis, cell types include
- fibroblasts
- adipose cells
- macrophages
dermis is composed of two layers: _ and _
papillary, reticular
areolar connective tissue with collagen and elastic fibers
papillary layer
papillary layer’s surface contains peg-like projections called _ _
dermal papillae
responsible for fingerprints and footprints
dermal papillae
80% of thickness of skin; dense irregular connective tissue
reticular layer
caused when skin is overstretched, dermis ruptures
striae (stretch marks)
stores fat and connects skin to muscles
subcutaneous tissue
shock absorber and insulator
hypodermis
lanugo or
fetal hair
lanugo is replaced near time of birth by _ hairs
terminal
columns of dead, keratinized epithelial cells
hair
has: shaft above skin, root below skin, hair bulb
hair
have growth and resting stage
hair
hair to stand on end produces _ _
goose flesh
glands found all over the body except on palms & soles
sebaceous glands
sebaceous glands = oily secretion called
sebum
active inflammation of sebaceous glands
acne
prevent overheating of body
sweat glands
sweat glands secrete _ and _
cerumen, milk
produce sweat, cools body
merocrine sweat glands
genital area, organic secretion broken down by bacteria causing body odor
apocrine sweat glands
in external ear canal that secrete cerumen (ear wax)
ceruminous glands
secrete milk
mammary glands
_ _ is covered by skin
nail root
visible part of nail
nail body
all of the nail is formed by
nail matrix
part of the nail matrix visible through nail body
lunula