Term
|
Definition
cosmetic
regulate body temp
vit D metabolism
sensory function
immune organ
preserve body integrity
absorbs, excrete fluid
protect from external insults/chemicals
water repellant
absorb UV light
barrier to microorganisms |
|
|
Term
|
Definition
variable from person to person
-in color, consistency, textures, thickness, content of adnexal structures |
|
|
Term
|
Definition
outer layer of skin
keratinizing stratified squamous epithelium |
|
|
Term
| cell types of the epidermis |
|
Definition
80% keratinocytes
10-15% melanocytes
3-5% Langerhans cells
<1% Merkel cells |
|
|
Term
|
Definition
main epidermis cell type
form 4 epidural layers:
basal, spinous, granular, cornified |
|
|
Term
|
Definition
aka stratum basale
single proliferative layer - deepest
basophilic (blue) columnar/cuboidal cells
cells divide and migrate up |
|
|
Term
|
Definition
aka stratum spinosum, stratum malphighii
sits on top of basal cell layer
usually thickest layer
polygonal cells with eosinophilic (pink) ctoplasm
desmosomal spines |
|
|
Term
|
Definition
aka stratum granulosum
1-4 cell layers thick
basophilic keratohyaline granules - like "glue" |
|
|
Term
|
Definition
aka stratum corneum
outermost layer
cells loose their nuclei and flatten out to form plated of keratin
shed as dead skin |
|
|
Term
| how long does it take for skin cells to completely turn over from basal layer to stratum corneum? |
|
Definition
30 days
~15 to get to bottom of stratum corneum, then another 15 before they are sloughed off |
|
|
Term
melanocytes
origin and location |
|
Definition
epidermal cells interspersed in the basal layer
neural crest origin
melanocytes:basal cells = 1:4 (face) 1:10 (body) |
|
|
Term
|
Definition
dendritic cell with stellate projections
cuboidal with eccentrically located, crescent-shaped nuclei
no desmosomoes |
|
|
Term
|
Definition
produce melanin pigment - UV protection
melanin is packaged in melanosomes and transported to spinous layer keratinoctyes |
|
|
Term
|
Definition
same number of melanocytes
dark skin: more evenly spaced melanosomes --> increased pigmentation |
|
|
Term
Langerhans cells
origin and location |
|
Definition
bone marrow derived, migrates to skin
found above the basal cell, scattered in the suprabasilar epidermis and dermis |
|
|
Term
Langerhans cells
morphology |
|
Definition
dendritic cell with stellate projections
unique cytoplasmic organelle - Birbeck's granules - seen ultrastructually, but function unknown |
|
|
Term
|
Definition
antigen presenting cell
mediator of skin immune response (delayed hypersensitivity rxn)
has surface markers for Fc, C3, and Ia antigens
numbers decreased with UV exposure |
|
|
Term
Merkel cell
origin and location |
|
Definition
found in epidermis and dermis
origin of cell is unknown |
|
|
Term
|
Definition
| membrane bound dense core granules (like neurosecretory granules of APUD system) |
|
|
Term
|
Definition
indiviual cell - unknown
cells aggregate to form tactile corpuscles that act as slow-adapting touch receptors and associate with peripheral nerves |
|
|
Term
basement membrane zone
OR
dermo-epidermal junction |
|
Definition
area of three zones that attaches eipdermis to the dermis
Lamina lucida
Lamina densa
Sublamina densa |
|
|
Term
lamina lucida
location and description |
|
Definition
basement membrane zone right under basal cell layer of epidermis
electron-lucent (more clear) zone |
|
|
Term
|
Definition
| anchoring filaments course through this zone, connecting the overlying basal cell at its hemidesmosone attachment plaque to the underlying lamina densa |
|
|
Term
|
Definition
aka basal lamina
actual "basement membrane"
Type IV collagen |
|
|
Term
|
Definition
| anchoring fibrils (made of Type VII collagen) and dermal microfibril bundles attach lamina dense to the underlying dermis |
|
|
Term
|
Definition
| intertwines with dermal collagen bundles |
|
|
Term
| 3 types of epidermal appendages |
|
Definition
pilosebaceous unit
apocrine gland
eccrine gland |
|
|
Term
| components of the pilosebaceous unit |
|
Definition
1. hair follicle
2. sebaceous gland
3. arrector pili muscle |
|
|
Term
| portions of the hair follicle |
|
Definition
the 3 I's:
infundibulum (most superficial)
isthmus
inferior |
|
|
Term
|
Definition
|
|
Term
|
Definition
glycogenated outer root sheath
internal root sheat |
|
|
Term
|
Definition
1. anagen (growth) phase
3-4 years, 85-90% of hairs
2. catagen (involutional) phase
3 days, 1% of hairs
3. telogen (resting) phase
3 months, 10-14% of hairs |
|
|
Term
|
Definition
found everywhere expect palms/soles
most abundant on face, chest, back and scalp |
|
|
Term
|
Definition
multilobular structure that connects to the infundibulum of the hair follicle
peripheral germinative cell layer
central lipid-laden cells with clear to foamy cytoplasm |
|
|
Term
|
Definition
gland secretes SEBUM (lipid oily mixture) to provide emollients to hair/skin
secrete via holocrine secretion - cytoplasm fills and cells burst |
|
|
Term
|
Definition
| a function of retrograde bursting of the sebaceous gland which then attracts an inflammatory reaction |
|
|
Term
arrector pili muscle
muscle type |
|
Definition
| smooth muscle that inserts into perifollicular connective tissue |
|
|
Term
arrector pili muscle
action |
|
Definition
| sympathetic contraction makes hair "stand up" (goose-bumps) |
|
|
Term
|
Definition
| axillae, groin, eyelids, external auditory canal |
|
|
Term
|
Definition
| secretory coiled gland that leads to straight duct |
|
|
Term
apocrine gland
secretory coiled gland |
|
Definition
outer myoepithelial layer (squeezes)
inner cuboidal/columnar layer
apocrine decapitation secretion
found in deep dermis/superficial fat |
|
|
Term
| apocrine decapitation secretion |
|
Definition
| cytoplasm fills up with sweat and then little bits get pinched off to release |
|
|
Term
apocrine gland
straight duct |
|
Definition
| connects to hair follicle (as part of the pilosebaceous unit) or skin surface |
|
|
Term
|
Definition
odorless secretions
unknown function
enlarge and become active at puberty
stim by excitment/fear (adgreneric innervation) |
|
|
Term
|
Definition
found everywhere except mucous membranes
dense on palms, soles, axillae, forehead |
|
|
Term
|
Definition
secretory coiled gland --> coiled duct --> straight duct --> spiraled duct
coils in epidermis, connects right up to skin surface |
|
|
Term
eccrine gland
secretory coiled gland |
|
Definition
smaller than apocrine gland; in deep dermis/superficial fat
outer myoepithelial layer
inner secretory layer (2 cell types) |
|
|
Term
eccrine gland
spiraled duct |
|
Definition
aka acrosyringium
intraepidermal portion
opens to skin surface |
|
|
Term
|
Definition
how we loose our heat
stimulated by thermal, mental, and gustatory stimuli
cholinergic innervation |
|
|
Term
|
Definition
connective tissue layer between epidermis and subcutaneous fat
-papillary dermis
-reticular dermis |
|
|
Term
|
Definition
superficial dermis
relatively thin, whispy, fine, collagen
Type III collagen |
|
|
Term
|
Definition
deeper dermis
larger and thicker
Type I collagen |
|
|
Term
dermis
connective tissue matrix components |
|
Definition
*collagen*
elastic substance
ground substance
*fibroblasts*
mast cells
dermal dendrocytes |
|
|
Term
| collagen types found in the dermis |
|
Definition
Types I, III, IV, VII
synthesized by fibroblasts
provide mechanical strength and extensibility |
|
|
Term
|
Definition
most abundant type
tightly bundled
reticular/deeper dermis |
|
|
Term
| Type III collagen - dermis |
|
Definition
more fine, loosely arranged than I
papillary dermis |
|
|
Term
| Type IV collagen - dermis |
|
Definition
basement membrane
lamina densa |
|
|
Term
| Type VII collagen - dermis |
|
Definition
basement membrane
anchoring fibrils |
|
|
Term
| elastic tissue of the dermis |
|
Definition
synthesized by fibroblasts
provides recoil and elastic properties
elastin and microfibrillar matrix containing fibrillin |
|
|
Term
| desmosine and isodesmosine |
|
Definition
| amino acids unique to elastin protein |
|
|
Term
ground substance
composition |
|
Definition
extracellular matrix
synthesized by fibroblasts, possibly mast cells
fibronectin and glycosaminoglygcans (mostly hyaluronic acid) |
|
|
Term
|
Definition
chief cell in the dermis
produces collagen, elastin, ground substance
contractile cell during wound healing (too many --> keloid) |
|
|
Term
|
Definition
free nerve endings
Meissner's corpuscle
Merkel cell complex
Pacinian complex |
|
|
Term
|
Definition
temperature, pain puritis
a lot on fingers
within papillary tips |
|
|
Term
|
Definition
fine touch
a lot on fingers
within papillary tips |
|
|
Term
|
Definition
|
|
Term
|
Definition
deep pressure, vibration
deep in dermis |
|
|
Term
| vascular supply to the skin |
|
Definition
deep vascular plexus
superficial vascular plexus
nutrient supply via diffusion |
|
|
Term
|
Definition
located at dermal-subcutaneous interface
arterioles arise from this plexus to supply epidermal adnexal structures and superficial vascular plexus |
|
|
Term
| superficial vascular plexus |
|
Definition
located in the papillary dermis
supplies capillaries, ed arterioles, and venules to dermal papillae |
|
|
