ch6pt2 Flashcards
skin color is influence by (2)
pigments and blood flow
pigments affecting skin color
carotene and melanin
can be converted to vitamin A, accumulates in epidermal cells and fatty tissues of dermis
carotene
produced by melanocytes in s. basale, stored in transport vesicles (melanosomes), transferred to keratinocytes
melanin
yellowish pigment waste, cleaned by liver
bilirubin
protects skin from sun damage (UV radiation)
melanin production from melanocytes
pigment found in RBC (red blood cells)
hemoglobin
oxygen bound to hemoglobin turns blood
bright red
severe reduction in blood flow or oxygenation. appears first in lips and nails
cyanosis (bluish skin tint)
epidermal cells produce ______ in the presence of UV radiation
vitamin D3/cholecalciferol
__________ convert vitamin D3 into ________
liver and kidneys; calcitriol
vitamin D3 helps with the absorption of
calcium and phosphorus
can cause rickets (weak/bendy bones)
insufficient vitamin D3
between epidermis and hypodermis/subcutaneous
dermis
anchors hair follicles and sweat glands. provides nutrients to epidermis using diffusion
dermis
two components of dermis
papillary layer and reticular layer
areolar connective tissue. contains small capillaries, lymphatics, and sensory neurons.
papillary layer
_________ project up between epidermal ridges in papillary layer
dermal papillae
deeper layer of dermis. dense irregular connective tissue.
reticular layer
contains larger blood vessels, lymphatic vessels, and nerve fibers. contains collagen and elastic fibers
reticular layer
has nerves
innervated
nerves fibers in skin control
blood flow, gland secretions
two types of sensory receptors
tactile corpuscles and lamellated corpuscles
sensory receptors in dermal papillae. sense lighter touches. aka Meissner’s corpuscles
tactile corpuscles
sensory receptors in reticular layer of dermis. sense deep pressure and vibration. aka Pacinian corpuscles
lamellated corpuscles
hypodermis (subcutaneous) layer is comprised of
connective tissue and adipose tissue
insulation, energy reserves, shock absorber and stabilizer
adipose tissue
hypodermis is connected to the reticular layer by
interwoven collagen fibers
covers everywhere except palms, soles, lips, and parts of external genitalia
hair
located deep in dermis, wrapped in dense connective tissue sheath
hair follicle
base of hair follicle surrounded by sensory nerves
root hair plexus
involuntary smoot muscle connected to hair root
arrector pili
secretes sebum, lubricates, controls bacteria
sebaceous glands
anchors hair, lower part beneath surface
hair root
exposed part of hair, not attached to the integument
hair shaft
part of hair containing capillaries
hair papilla
swollen region/base of hair
hair bulb
hair bulb produces _______ (dividing basal cells)
hair matrix
determined by genes. produced by melanocytes near hair papilla
hair color
types of hair (2)
vellus hairs and terminal hairs
soft, fine hairs. covers body
vellus hairs
thick, may be heavily pigmented hair. on head, eyebrows, and lashes. spreads after puberty
terminal hairs
glands which secrete oils onto the skin
sebaceous glands
types of sweat (sudoriferous) glands
apocrine glands and merocrine (eccrine) glands
Sudoriferous glands which excrete watery sweat
merocrine (eccrine) glands
sebaceous gland associated with hair follicles
simple branched alveolar glands
discharges sebum directly onto skin surface
sebaceous follicles
