Integumentary System Flashcards
considered as the true covering surface of the body
integument skin
largest organ of the vertebrate body
integument skin
15-16% of total human body weight
integument skin
covers area of 1.6 m^2 (17.5ft)
for average women
covers area of 2.0 m^2 (21.5ft)
for average men
about 1 to 2 mm thick
skin
0.5 mm thick on the _
eyelids
6mm thick on the _
palms and soles
how many dead skin cells are shed in a lifetime?
40kg (88 lb)
how many nerve endings, hairs, muscle, sweat glands, oil glands, blood vessels, heat receptors, cold receptors and pressure-sensing receptors are contained in one sq cm of human skin?
200 nerve endings, 10 hairs and muscles, 100 sweat glands, 15 oil glands, 3 blood vessels, 12 heat receptors, 2 cold receptors, 25 pressure-sensing receptors
7 functions of epidermis
1) covering and protection
2) secretion of substances
3) excretion of metabolic wastes
4) sensation and regulation of temperature
5) storage of reserved food
6) nourishment
7) respiration (in amphibians)
thin, upper part of the skin composed of stratified squamous layer of epithelial tissue
epidermis
10 to 30 cells thick, about as thick as a page
epidermis
outermost layer composed of dead cells packed with keratin
stratum corneum
tough, water proof protein
keratin
translucent layer, composed of flat dead and non-nucleated cells
stratum lucidum
composed of keratohyaline granules
stratum granulosum
prickle cell layer, composed of langerhans cells
stratum spinosum
inner layer, composed of actively dividing cells
stratum germinativum (basale)