Intergumentary Flashcards
what are the structures of the skin?
Epidermis
Basement membrane (dermoepidermal
junction)
Dermis
Subcutaneous fat
layers/ parts of epidermis
- stratum corneum (cornified layer) 2
- stratum lucidum (found on thick skins)
- stratum granulosum
- stratum spinosum
- stratum basale/germinativum
Parts of dermis
- collagen fibers & elastic fibers
- extracellular matrix
- blood vessels
- nerves
- smooth muscles
what are the skin appendages?
hair follicles s
sebaceous gland
arrector pili muscle
eccrine & apocrine sweat glands
nail
It deals with disorders of skin, hair, nails, and
mucous membranes
Dermatology
this is the outer layer of the skin
epidermis
this is the part of the skin that has thicker connective tissue
dermis
Functions of integumentary system
- Protection
- Sensation
- Movement and growth
- Endocrine - Vitamin D production
- Excretion - Regulation of sweat
- Immunity - First line of defense
- Temperature regulation
Classified as a membrane - the cutaneous
membrane
Two main layers
Epidermis - outer, thinner
Dermis - inner, thicker
The two layers are separated by a basement
membrane
Skin
Composed entirely of stratified squamous
epithelium
Lacks blood vessels
Composed of four, or in the palm and sole, five distinct layers
Epidermis
- The outermost layer of cells harden and die in a process called ______________
- The total process takes ~2 months.
involves the formation of keratin polypeptides
abnormalities in this process leads to roughness
and scaling of the skin (e.g. psoriasis)
keratinization
– outermost layer, composed
of layers of dead, non-nucleated, keratinized
cells
- The cells in this layer have no nucleus .
Cells have thick envelope that resist chemicals.
Cells are held together by desmosomes.
- it is 25-cell layer
stratum corneum
on soles and palms only,
appears clear
stratum lucidum
- 3 to 5 layers of flattened, granular cells
- Granular Cell layer : Diamond- shaped cells.
Cytoplasm is filled with keratohyaline granules.
In thin skin it is cell layers and 10 cell layers in thick skin like palms and soles.
stratum granulosum
- many layers of nucleated
cells, becoming flattened, developing keratin
fibers - Usually layers thick .
Adhere to each other by desmosomes (complex
modification of the cell membrane ).
Desmosomes appear like spines.
stratum spinosum
- deepest layer, single layer of cuboidal or columnar cells that are growing and dividing
- Rest on the basement membrane that divides continuously and move upwards.
stratum basale
Specialized cells in the stratum basale of the
epidermis with long processes that extend into
the stratum spinosum
Produce the dark pigment melanin which
provides skin color
Melanin production is stimulated by ultraviolet radiation
melanocytes
are transferred to adjacent cells
forming the Epidermal Melanin unit
melanosomes
Small, unmelanized, clumped melanosomes are found in _____________
white skin
Large melanized, dispersed melanosomes in
_________________
dark skin
skin structure components of basement membrane
lamina lucida
lamina densa
anchoring fibrils
: thin clear amorphous space
lamina lucida
an electron dense area
containing type 4 collagen
lamina densa
: anchors epidermis to dermis,
type 7 collagen
anchoring fibrils
Pink homogenous area between epidermis & dermis
consists of number of proteins like BP antigens, collagen 4
site of attack injury in blistering diseases
basement membrane
skin cancers
Squamous cell carcinoma
Basal cell carcinoma
Malignant melanoma
what are the two layers of dermis?
papillary area and reticular area
has projections up into the
epidermal layer, provides nutrients to the
epidermis via its abundant blood vessels
papillary area
denser, deeper, main area of the dermis, mat of irregularly arranged fibers resistant to stretching
reticular area
what are the dermis cells?
histocyte
fibroblast
mast cell
composed of adipose tissue
subcutaneous fat
it harness the adipose tissue or lipid/ fats
adipocytes
this is the primary sensory cells that are for tactile stimulus that have low pressure stimulus
merkell cells
they have high pressure stimulus
paccinian cells
present everywhere except the vermilion border of the lips, nail beds, labia minora, glans
abundant in palms, soles
eccrine sweat glands
present in the axillae, anogenital area modified glands in the external ear canal, eyelids (moll’s glands) and areolae
apocrine sweat glands
attached to hair follicles or open freely
present in the scalp, forehead, face,
upper chest except palms and soles
under the control of androgens
ectopic glands in the mucous membrane
are called fordyce spots.
present in the areola as Montgomery’s
tubercles, in the eyelids as Meibomian glands
sebaceous glands
attached to sebaceous gland to form the
pilosebaceous unit (hair follicle, hair shaft,
sebaceous gland)
hair follicles
region between skin surface
& sebaceous gland
infundibulum
- begin at sebaceous glands and end aat
bulge area (site of insertion of arrector pili
muscle)
isthmus
smooth muscle located in the
dermis and is attached to the side of the hair
shaft
arrector pili
cuticle, cortex contain pigment cells, medulla
hair shaft
types of hair
- Terminal Hair
- Lanugo Hair
- Bristle Hair
- Villus Hair
made up of dead keratinized cells of
matrix.
nail plate
is visible through nail plate.
nail bed
lies above the midportion of distal
phalanx.
nail matrix
Functions as a hormone for the incorporation of ingested calcium into the bones
Vitamin D
Skin exposed to the ultraviolet rays of the sun converts pro-Vitamin D to Vitamin ____
D3
