skin Flashcards
dermatology
study of skin
responsibilities of skin
acts as a barrier to microorganisms protects the underlying structures from injury prevents you from drying out acts as a receptor for sensations maintains and regulates body temperature Vitamin D metabolism
Body balances
heat production and heat loss
heat loss from the skin occurs ___ways
4 radiation conduction convection evaporation
radiation
heat energy is transmitted via waves to surrounding ares
conduction
heat energy is transmitted via contact
convection
transfer happens via a gas or liquid or by circulation of a current
evaporation
sweat of fluids on the skin absorb heat and change to vapor
heat loss also happens via
mucus membranes of the respiratory tract
skin of comprised of ___ principle layers
2
dermis
epidermis
epidermis
outer, thinner visible layer of the skin
dermis
inner, thicker layer of the skin
epidermis layers
basal layer spinous layer granular layer clear layer horny layer
basal layer
continuously multiplying to compensate for cell loss on the surface
pushes upwards into next layer
contains melanin that gives skin pigment
spinous layer
usually one to two layers thick, can be thicker in regions that are more rugged
granular layer
granules visible in cytoplasm of cells
begins to pack the cells with fibrous protein called keratin
process is called kertatinization or cornification
cells begin to die at this leve
clear layer
tightly packed clear cells
horny layer
fat, lifeless, cornified cells
appear as overlapping,
when unbroken, for a barrier to microorganisms,
dead cells are constantly sloughed off this layer and replace by ones from the basal layer
keratinization
gives strength to special epidermal parts such as horns, hooves, beaks, and hair
albinism
absence of normal pigmentation
cyanosis
blue hue to the skin where there is reduced oxygen supply
dermis
made of dense fibrous connective tissue and contains blood vessels and nerves
arrector pili
muscles that attach to hair follicles
contraction of this muscle causes hair to raise
increased insulation
raising of hackles
sebaceous glands (oil producing), sweat glands, and sensory receptors
are all found in the dermis
hypodermis or subcutis
found beneath the dermis (hypo - under, beneath)
hypodermis is composed of
loose connective and fatty tissue
it allows
skin to move over underlying structure without damage
skin thickness/looseness varies depending on
location
