Integumentary Sys. Flashcards
funcs. of skin (6)
thermoregulation
protection
cutaneous sensation
excretion and absorption
synthesis of vitamin D
immunity
The integumentary system consists of
skin and derivatives such as hair, glands, sensory structures, nails
being that skin is stratified, keratinized epithelium with lipids, it provides a _______ and _______ _____ barrier
mechanical and water proof
sebum keeps skin soft and controls ______ ____
bacteria growth
protects from UV-ray damage
melanin
rickets in children and osteomalacia in adults are disorders of ______ __ deficiency
vitamin D
skin consists of (2)
epidermis and dermis
-deep to dermis
-not part of skin
-anchored to dermis via fibers and areolar tissue
-contains many adipocyte, blood vessels that supply the skin, pressure receptors
subcutaneous layer (hypodermis)
epidermis is ________
avascular
4 types of cells in epidermis
keratinocytes, melanocytes, Langerhans cells, Merkel cells
feats of keratinocytes
-makes up 90% of epidermal cells
- produce and fills up with keratin
-produces lamellar granules
what do lamellar granules do
release lipid-based waterproofing sealant that fills intercellular spaces and impedes invasion of microbes
what is keratin and what does it do
fibrous protein that provides protection from heat, abrasion, microbes and chemicals
what do melanocytes do
produce melanin (black-brown pigment) and provides protection from UV-rays
Merkel cells are found in the _______ layer of epidermis and connect to _________ _____
Deepest, Merkel (tactile) discs (nerve endings)
5 layers of epidermis (bsglc)
- stratum basale (stratum germinativum)
- stratum spinosum
- stratum granulosum
- stratum lucidum
- stratum corneum
one of the 5 layers of epidermis with 8-10 rows of closely packed spiny, polyhedral keratinocyte cells
stratum spinosum
one of the 5 layers of epidermis with cells that develop darkly staining granules (of keratohyalin), contain lamellar granules, and undergoes apoptosis
stratum granulosum
epidermal layer found only in the skin of the palms and soles of feet with 3-5 layers of clear, flat, and dead keratinocytes
stratum lucidum
epidermal layer with 25-30 rows of flat dead keratinocytes completely filled with keratin
stratum corneum
an abnormal thickening of the stratum corneum from constant friction
callus
what is keratinization
4 week process in the epidermis in which cells form in a basal layer, rise up to the surface, become keratinized, die (apoptosis) and are sloughed off. Forms protective layer