Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
31 Cards in this Set
- Front
- Back
|
fxn of skin
|
protect
sensory info temp regulation Ag recog sexual attraction (apocrine) |
|
|
differences in skin from different areas of the body are primarily due to:
|
relative diff in 4 basic layers and distribution of adnexal structures
|
|
|
what are the 4 basic skin layers? which is the most important pathologically?
|
epidermis
papillary dermis (most imp) reticular dermis subcutaneous/hypodermis |
|
|
what are the 3 types of adnexal structures?
|
hair/pilar units (pilosebaceous units, arrector pili mm)
eccrine units (glands, ducts) apocrine (exit with hair shaft) |
|
|
where is the bulk of the adnexal structures located?
|
reticular dermis; extend to exit via ducts in epidermis
|
|
|
what is the basket weave like structure in the superficial epidermis?
|
horny layer=stratum corneum
dead cells lacking nuclei (clear); only keratin (extracellular?) |
|
|
what are the layers of the epidermis?
|
stratum corneum, lucidum, granulosum, spinsosum, basale
|
|
|
whats going on in the stratum granulosum?
|
dense (red), compact keratin
making keratin hyalin granules that serve as the glue to hold the keratinocytes together |
|
|
where do the keratinocytes proliferate and why do they appear more dense in the basal layers?
|
proliferate in the basal layers; one stays one moves us; as moves up, grows considerably, filling with keratin
|
|
|
which layer of the skin accumulates fluid in edema? where is it located?
|
papillary dermis (expansile)
relatively thin layer below the epidermis |
|
|
what constitutes a squamous cell?
|
makes keratin
has intercellular jxns (desmosomes) |
|
|
what do melanocytes look like histologically?
|
located in stratum basale
distinct nucleus with surrounding halo no desmosomes |
|
|
what are melanosomes and where are they located?
|
convert DOPA to melanin
passed from the melanocyte to the keratinocyte which carries it to the surface |
|
|
charac of stratum basale
|
single keratinocyte layer (columnar, cuboidal); stem cells
hemidesmosomes attach to BM desmosomes conn cells also, melanocytes and merkel cells present |
|
|
what and where are the dendritic cells present?
|
langerhans cells in the upper spinous layer (APC)
|
|
|
what are rete pegs?
|
epidermal invaginations into dermis; flatten with age
(anchor, taughtness) |
|
|
what are dermal papillae?
|
dermal evaginations (papillary dermis) into the epidermis
|
|
|
what is the plexus in the papillary dermis that contributes to blushing?
|
superficial vascular plexus
|
|
|
what is a meissner's corpuscle? where are they located?
|
special nerve ending (touch receptor)
only in dermal papillae most on hands and feet |
|
|
how do the fibers of the papillary and reticular dermis differ?
|
papillary: fine, delicate, reticular, elastic fibers
reticular: course, thick, collagen bundles |
|
|
what are charac of reticular dermis? where is it the thickest?
|
fxn: stable platform for epidermis
adnexal structures thickest in areas of pressure (back, butt, scalp) |
|
|
what is a pacinian corpuscle? where is it located?
|
encapsulated nerve ending (pressure receptor)
in deep dermis->hypodermis |
|
|
what detects pain and temp in the skin? what controls blood flow and hair in the skin?
|
pain, temp: free nerve endings
SNS for blood, hair |
|
|
characteristics of subQ tissue
|
loose and dense CT
adipocytes, fibroconnective tissue connects reticular dermis with fascia of tissue below (mm, bone etc) vascular (deep vascular plexus) body temp regulation fat storage, energy reserve lost with age ->frail esp in hands, feet |
|
|
where are some of the most rapidly dividing cells in the body?
|
hair bulb (chemo)
|
|
|
what empties into the infundibulum of the hair follicle?
|
sebaceous glands (lubricates)
|
|
|
eccrine gland: location, charac
|
(sweat gland)
in mid to low reticular dermis coiled |
|
|
apocrine glands: location, charac
|
deep dermis or at jxn of reticular dermis and subQ
axilla, perineum, scalp pink b/c have high mitochondria |
|
|
age-related changes in skin
|
flattening/loss of rete pegs at dermal/epidermal jxn
increased sheer (not decreased elasticity) hair shaft decreases in diameter decr number of hair follicles/decrease oil prod change distribution of hair loss subQ fat |
|
|
what is Lentigo Senilis (Solar Lentigo)? where does it occur? why does it occur?
|
defn- benign, discrete hyperpigmented macule
seen on backs of hands (liver spots) and forehead (exposed) occurs due to xs melanin in keratinocytes (NOT b/c of more melanocytes) |
|
|
what is another word for "sun-induced" damage?
|
actinic damage
|
