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