Chapter 5: Integumentary System Flashcards
integumentary system
skin, subcutaneous tissue, oil glands, sweat glands, hair, and nails
epidermis
superficial region of thick epithelial tissue
dermis
deep to the epidermis, a fibrous connective tissue
hypodermis
lies deep to the dermis, composed of loose areolar connective tissue and adipose tissue
functions of skin and hypodermis
protection, body temperature regulation, excretion, production of vit D, and sensory reception
keratinocytes
produce keratin, a fibrous protein (protective)
melanocytes
location-basal layer, manufacture and secrete pigment
tactile epithelial cells
location-basal layer, attached to sensory nerve endings
dendritic cells
location-stratum spinosum, part of immune system
5 strata layers
stratum basale, stratum spinosum, stratum granulosum, stratum lucidum(only in thick skin), and stratum corneum
stratum basale
deepest epidermal layer, cells actively divide (tactile epithelial cells& melanocytes)
stratum spinosum
contains thick bundles of intermediate filaments: contains star-shaped dendritic cells
stratum granulosum
consists of keratinocyts, kertohyaline granules (form keratin), and lamellated granules( contain waterproofing glycolipid)
stratum lucidum
composed of a few rows of flat, dead keratinocytes(only found in thick skin)
stratum corneum
topmost layer; thick layer of dead keratinocytes and thickened plasma membranes; protects against abrasion & penetration; cells shed regularly
dermis
strong, flexible connective tissue; with lots of blood vessels and nerves; has paillary dermis& reticular layer
papillary dermis
includes dermal papillae (extends into epidermis
reticular layer
deeper layer; more thick; dense, irregular connective tissue; separations between collagen bundles form cleavage lines
subcutaneous tissue
hypodermis; areolar and adipose connective tissue; stores fat and anchors skin to underlying structures
melanin
UV protection; variation in skin color due to amounts of pigment
carotene
yellowish-orange; obtained from vegetables
hemoglobin
crimson color of oxygenated blood
nails
scalelike modification of epidermis (hard keratin)
hair
flexible strand of dead, keratinized cells; hard keratin-tough and durable
vellus hairs
body hairs of women and children
terminal hairs
hair of scalp, axillary and pubic area
root
imbedded in the skin
shaft
projects above skin’s surface
medulla
central core (absent in fine hairs)
cortex
surrounds medulla & consists of several layers of flattened cells
cuticle of hair
outermost layer (shingles)
hair follicles
extend from epidermis into dermis
hair bulb
deep, expanded end of the hair follicle
root plexus
knot of sensory nerves around hair bulb
dermal papilla
stimulates hair growth and nutrients
wall of hair component
peripheral connective tissue sheath; glassy membrane; and epithelial root sheath
sebaceous glands
over most body except palms and soled; secrete seubum; secreation stimulated by hormones
sebum
collects dirt; soften and lubricates hair and skin
sweat gland
widely distributes on body; eccrine and apocrine
eccrine sweat glands
most common (true sweat); most abundant on palms, soles, and foreheads
apocrine sweat glands
secrete water, some fats and proteins (start to function at puberty)
modified sweat glands
ceruminous (ear) and mammary glands
sweat
blood filtrate; 99% water (some salts; ~2% urea)
