Chapter 5 Flashcards
comprised of skin and its accessory components including hair, nails, and associated glands
integumentary system
three layers of the skin
epidermis
dermis
subcutaneous fascia (hypodermis)
there are no blood vessels or nerve endings in this layer. cells on surface are constantly shedding, being replaced with new cells that grow and arise from deeper region called stratum basale every 2–4 weeks
epidermis
outermost layer of dead cells which are flat, scaly, and keratinized
stratum corneum
deepest epidermal layer and attaches the epidermis to the basal lamina, below which lie the layers of the dermis.
stratum basale
the cells in the stratum basale bond to the
dermis via intertwining collagen fibers called…
basement membrane
stratum basale is a single layer of cuboidal-shaped…
keratinocytes
formation of new keratinocyte cells
existing cells are pushed superficially away from the stratum basale.
two other cell types in stratum basale
merkel cell and melanocyte
which functions as a receptor and is responsible for stimulating sensory nerves that the brain perceives as touch.
merkel cell
a cell that produces the pigment melanin. Melanin gives hair and skin its color, and also helps protect the living cells of the epidermis from ultraviolet (UV) radiation damage.
melanocyte
other name for stratum basale
stratum germinativum
spiny in appearance due to the protruding cell processes
that join the cells via a structure called a desmosome.
stratum spinosum
interlock with each other and strengthen the bond
between the cells.
desmosomes
it is interesting to note that the “spiny” nature of the stratum spinosum is an artifact of the…
staining process
has a grainy appearance due to further changes to the keratinocytes as they are pushed from the stratum spinosum.
stratum granulosum
become flatter, their cell membranes thicken, and
they generate large amounts of the proteins keratin
stratum granulosum
a smooth, seemingly translucent layer of the epidermis located just above the stratum granulosum and below the
stratum corneum. This thin layer of cells is found only in the thick skin of the palms, soles, and digits.
stratum lucidum
the keratinocytes that compose the stratum lucidum are [ ]
dead and flattened
these cells are densely packed with [ ], a clear protein rich in lipids, derived from keratohyalin, which gives these cells their transparent (i.e., lucid) appearance and provides a barrier to water.
eleidin
the most superficial layer of the epidermis and is the layer
exposed to the outside environment. The increased keratinization (also called cornification) of the cells in
this layer gives it its name.
stratum corneum
contains blood and lymph vessels, nerves, and other structures, such as hair follicles and sweat glands.
dermis
the dermis is made of two layers of connective tissue that compose an interconnected mesh of [ ] and [ ], produced by [ ]
elastin, collagenous fibers; fibroblasts
made of loose, areolar connective tissue, this
superficial layer of the dermis projects into the stratum basale of the epidermis to form finger-like dermal papillae.
papillary layer
contents within the papillary layer
fibroblasts, adipocytes (fat cells), small blood vessels
in addition, the papillary layer contains [ ], defensive cells that help fight bacteria or other infections that have breached the skin.
phagocytes
other contents of papillary layer
lymphatic capillaries, nerve fibers, and touch receptors called the Meissner’s corpuscles.
composed of dense, irregular connective tissue. This layer is
well vascularized and has a rich sensory and sympathetic nerve supply
reticular layer
the reticular layer appears reticulated (net-like) due to a tight meshwork of [ ] which provide some
elasticity to the skin, enabling movement.
elastin fibers
provide structure and tensile strength, with strands of
it extending into both the papillary layer and the hypodermis.
collagen fibers
a layer directly below the dermis and serves to connect the skin to the underlying fascia (fibrous tissue) of the bones and muscles.
hypodermis
The hypodermis consists of well-vascularized, loose, areolar
connective tissue and adipose tissue, which functions as a…
mode of fat storage and provides insulation and
cushioning for the integument.
the color of skin is influenced by a number of
pigments…
melanin, carotene, hemoglobin
the melanin is transferred into the keratinocytes via
a cellular vesicle called…
melanosome
how do skin heals
wound fills with blood; blood contains substances that
cause clotting; top part of clot exposed to air hardens to
form scab, nature’s band-aid, forming barrier and
preventing pathogens from entering. Next, white blood cells enter and destroy any pathogens, while fibroblasts come and begin pulling edges of wound together; basale layer hyper-produces cells for repair of wound
composition of scar
collagen fibers
scars don’t contain…
accessory organs or nerve endings
As cells grow out and over nail bed, they become [ ] forming substance similar to horns on a
bull
keratinized
fold of tissue that covers nail root
cuticle
origin of the pink color of nails
vascularization of tissue under nails
white half-moon shape of nail formed as a result of thicker layer of cells at the base
lunula
formed by epithelial cells with rich source of blood provided by dermal blood vessels
follicle
composition of hair shaft
cells divide and grow in base of follicle, older cells
are pushed away and die, so shaft of hair is comprised of
dead cells
hair color depends on the amount and type of [ ] you produce
melanin
red hair is a result of hair that has melanin with [ ] in it
iron
[ ] hair shafts produce curly hair, while [ ] shafts produce straight hair
flat, round
a term for any type of hair loss and can be acute or chronic
alopecia
part of regulation of temperature is accomplished by changes in side of [ ]
blood vessels
exposes heated blood to external cooling air
vasodilation
keeps cooling of blood to a minimum when it’s cold outside
vasoconstriction
sweat glands excrete water onto skin’s surface, allowing cooling through [ ]
evaporation
[ ] causes muscle activity that produces heat
to warm you when you’re cold
shivering
hairs on skin stand erect when [ ] contract; known as goose bumps;
arrector pili muscles
these hairs create [ ] insulating you
from cooler surroundings, like a goose down jacket
dead space
