Integumentary System Flashcards
what are the two primary layers of skin
epidermis
dermis
what germ cell layer is the epidermis derived from
ectoderm
what germ cell layer is the dermis derived from
mesoderm
what tissue is composed of variable amounts of adipose tissue arranged into lobules separated by connective tissue septa below the dermis
hypodermis
what 5 appendages are derived from the epidermis
hair
sweat glands
sebaceous glands
nails
mammary glands
what are the 5 major functions of the integumentary system
barrier
immunologic
sensory
endocrine
excretion
what makes therapeutic substances absorbable through the skin
they are lipid-soluble
what are the two most common locations to find thick skin
palms and soles
which type of skin would be expected not to have hair, thick or thin skin
thick
what are the 5 layers of the epidermis
basale
spinosum
granulosum
lucidum
corneum
what is the most mitotically active layer in the skin
basale
what are the shape and distribution of cells within the stratum basale
simple cuboidal or columnar
what are the 2 adhesive proteins found within the cell junctions of the stratum basale
desmosomes and hemidesmosomes
what is the type of stem cell that is present within the stratum basale that forms the epidermis
keratinocytes
in what layer of the skin does apoptosis become evident
granulosum
what cell layer is most likely to stain with a high concentration of darker basophilic cells in the epidermis
granulosum
what cell layer of the epidermis exhibits numerous cytoplasmic processes or spines which give this layer its name and is many cells thick
spinosum
what shape cell would be expected in the stratum spinosum
flattened
what type of basophilic staining granules are found within the keratinocytes of the stratum granulosum
keratohyalin
what is the most superficial layer of nonkeratinized portion of the epidermis
granulosum
what layer of the epidermis displays nucleated cells
corneum
where are the 2 most common places to have a thick stratum corneal layer
thick skin and sites of skin friction
what layer of skin is usually only associated with thick skin and considered a subdivision of the stratum corneum
lucidum
what are the finger-like connective tissue protrusions that project into the undersurface of the epidermis called
papillae
what are the two layers of the dermis
papillary and reticular
what forms the basis of fingerprints and footprint patterns
dermal ridges
what two types of collagen are most prominent in the papillary layer of the dermis
type 1 and type 3
what two types of fibers are most prominent in the reticular layer of the dermis
type 1 collagen and elastin
what is the name of collagen fibers that parallel underlying muscle referred to as
langer lines
what are two functions of the fat layer within the hypodermis
energy source and insulation
what type of skin cancer is most likely to arise from the stratum basale
basal cell carcinoma
what are the four specialized cells of the epidermis
keratinocytes
melanocytes
langerhans cells
merkel’s cells
approximately 85% of the epidermis is composed of what cell type
keratinocytes
where are melanocytes found in the epidermis
basal cell layer and extend into the spinosum
what specialized cell within the epidermis serves an immunologic function as part of the mononuclear phagocyte system to present antigens
langerhan’s cells
what specialized cell within the epidermis functions as a sensitive mechanoreceptor cells associated with sensory nerve endings
merkel’s cells
what 2 important functions do lamellar bodies have
form intracellular epidermal water barrier
have granules that coat membrane
which organelle is responsible for forming lamellar bodies
Golgi
what are the three stages of cell replacement in the epidermis
division of basal cells in the basale layer
differentiation and programmed cell death as cells move towards corneum
cell loss at skin’s surface
what is the average cell turnover time for the stratum spinosum and granulosum
28-31 days
what is the average cell turnover for the stratum corneum
12-14 days
what is the average cell turnover of the entire epidermis
42-47 days
what skin condition is consistent with an autoimmune etiology and hyper proliferation of the epidermis, resulting inn elevated, itchy, scales on which are most seen on the knees, elbows, lower back, and scalp
psoriasis
what are the lysosome-related membrane-bound structures produced by melanocytes that are involved in melanin synthesis formed by the Golgi apparatus of these cells called
premelanosomes
how does melanin enter the keratinocytes
phagocytosis
what four intrinsic and extrinsic factors can affect skin pigmentation
age
ethnicity
gender
genetic defects
which enzyme is absent in albinism
tyrosinase
what are the two main types of albinism
ocular
oculocutaenous
what are the two genes most responsible for aging
Bcl2
Mitf
what condition loses melanocytes that results in discolored patches in different areas of the body
vitiligo
where are Langerhans cells most often seen using IHC techniques
spinosum
what is the cell of origin for Langerhans cells
common lymphoid progenitor (CLP)
where are Merkle cells found
basale
what function do Merkle cells have
release neurotransmitters
what is a fast adapting, encapsulated nerve ending found in the skin which responds to low frequency vibrations in eyelids and fingertips
Meissner corpuscle
what is a slow adapting, unencapsulated nerve ending found in the skin which responds to light touch, and is commonly seen in the superficial dermis of fingertips and lips
Merkel’s Disks
