Ch 6: Skin Flashcards
Main layers of skin
Epidermis
Dermis
Hypodermis
Epidermis
Outer layer of skin. Composed of squamous epithelial tissue.
Dermis
Inner layer of skin. Composed of connective tissue. Contains blood vessels, sweat glands, sebaceous glands, nerve endings, hair follicles.
Hypodermis
Beneath the dermis. Made of areolar and adipose connective tissue.
Layers of epidermis
Stratum basal- innermost layer columnar stem cells
Keratin- cells are pushed upwards and produce keratin. Cells flatten as they move to the top
Stratum corneum- outer layer: keratinocytes replace dead cells and they flake away
Types of melanin
Pheomelanin- red
Eumelanin-black/brown
Function of melanin
Protects cells from UV damage
Functions of skin
-Protection from bacteria and toxins
-Barrier to prevent water from getting in or out, blocks uv rays
-vitamin d production
-sensory perception
-Thermoregulation (sweating)
Parts of hair from base to tip
-papilla- connective tissue and blood vessels that nourish hair
-hair bulb (root)
-hair follicle (sheath where hair lives)
-arrector pilli- muscles that control hair
-shaft
Nail structures
-nail body
-cuticle
-lunula (half-moon base)
-nail bed (under nail)
-nail root (beyond cuticle)
Types of skin glands
Eccrine, apocrine, sebaceous, ceruminous
Sweat glands
Apocrine- contain a duct that leads to hair follicle. Scent glands mainly respond to stress and sexual stimulation
Eccrine- duct leads directly to skin surface
Sebaceous glands
Open into hair follicle, secrete an oily substance (sebum) to keep hair and skin from drying out.
Ceruminous glands
Produces earwax (cerumen) to prevent ear from drying out.
