introduction Flashcards
includes the skin and its
accessory structures
including hair, nails, and
glands, as well as blood
vessels, muscles and
nerves
integumentary system
is the medical specialty for the
diagnosis and treatment of
disorders of the integumentary system
dermatology
covers the
body and is the largest
organ of the body by
surface area and weight
cutaneous membrane or skin
weighs _-_kg about 16% of the body
4.5-5kg
thinnest skin
eyelids
thickest skin
soles
the average thickness is?
1-2mm
outer, thinner layer called the ___
consists of epithelial tissue
epidermis
inner, thicker layer called the
dermis
Beneath the dermis
subcutaneous layer (hypodermis)
composed of
keratinized stratified
squamous epithelium
epidermis
4 cells of the skin
keratinocytes
melanocytes
langerhans cells
merkels cells
90% produce keratin
which is a tough fibrous
protein that provides
protection
keratinocytes
produce the pigment
melanin that protects
against damage by
ultraviolet radiation
melanocytes
involved in immune
responses, arise from
red bone marrow
langerhans cell
function in the
sensation of touch
along with the
adjacent tactile discs
merkel cells
where continuous cell division
occurs which produces all the other layers
stratum basale or start germinativum
where continuous cell division
occurs which produces all the other layers
stratum basale or start germinativum
8-10 layers of keratinocytes
stratum spinosum
which includes
keratohyalin and lamellar granules
stratum granulosum
is present only in thick skin (the
skin of the fingertips, palms, and soles)
stratum lucidum
composed of many sublayers
of flat, dead keratinocytes (constant friction can stimulate formation of a callus).
stratum corneum
the
accumulation of
more and more
protective keratin,
occurs as cells move from the deepest
layer to the surface
layer
keratinization
an
excess of
keratinized cells
shed from the scalp
dandruff
is composed of
connective tissue
containing collagen
and elastic fibers
dermis
contains
collagen and elastic
fibers
papillary region
includes touch
sensors and free nerve endings
dermal papillae
consists of
collagen and
elastic fibers,
adipose cells, hair follicles, nerves,
sebaceous (oil)
glands, and
sudoriferous
(sweat) glands
reticular region
“tension lines” in the skin
indicate the predominant
direction of underlying
collagen fibers
lines of cleavage
reflect
contours of the underlying
dermal papillae and form
the basis for fingerprints
(and footprints);
epidemal ridges
their
function is to increase
firmness of grip by
increasing friction.
epidermal ridges
attaches the skin to
the underlying
tissues and organs
subcutaneous layer (hypodermis)
three pigments
melanin,
carotene, and hemoglobin
a yellow-red or brown-black pigment
produced by melanocytes (located mostly in the
epidermis, where it absorbs UV radiation)
melanin
A benign localized overgrowth of
melanocytes is a
mole
an inherited inability to
produce melanin
albinism
a condition in which there
is a partial or complete loss of
melanocytes from patches of skin
vitiligo
yellow-orange pigment
(found in the stratum corneum,
dermis, and subcutaneous layer)
carotene
produced in blood cells
hemoglobin
what are the functions of hair
protection
reduction of heat loss
sensing light touch
mostly projects above the
surface of the skin
hair shaft
penetrates into the dermis
root
what are the types of hair
lanugo, vellus hairs and terminal hairs
is determined by the amount and
type of melanin
hair color
are connected to
hair follicles
sebaceous glands
is very fine, soft,
and usually unpigmented,
downy hair on the body of
a fetus or newborn baby.
lanugo
is short, fine, light-colored, and
barely noticeable hair that develops on most of
a person’s body from his/her childhood.
vellus hair
are thick, long, and dark, as
compared with vellus hair.
terminal hair
