Integument and Barriers to Infection Flashcards Preview

HDM Midterm > Integument and Barriers to Infection > Flashcards

Flashcards in Integument and Barriers to Infection Deck (30):
1

dermal-epidermal junction

surface of palms/soles has epidermal ridges with intervening furrows
each ridge follows the outline of an underlying dermal ridge/papilla -- hemidesmosomes create tight junction

2

Layers of Epidermis

Stratum: Corneum
lucidum (not in thin skin)
granulosum
spinosum
basale

3

stratum basale

mitotically active layer
replaces skin every 15-30 days
single layer of cuboidal, low columnar cells bound to keratinocytes apically

4

stratum spinosum

polyhedral keratinocytes
produces cytokeratin which aggregates to tonofilaments

5

malpghian layer

consists of the stratum basale and the stratum spinosum

6

stratum granulosum

contain granules
1) keratohyalin granules: basophilic, non-membrane bound granules (cystine and histadine rich protein, assembles keratin into bundles)
2) lamellar granules: lipid rich, barrier to foreign material and water loss

7

stratum lucidum

translucent band of cells with no organelles or nuclei
densely packed keratin filaments

8

stratum corneum

multiple layers of cells with mature keratin (Squames == fully keratinized)
continuously shed
thick skin: 15-40 layers
thin skin: 10-20 layers

9

melanocytes

originate from neural crest - first cells to arrive in epidermis
located in stratum basale - contacts about 36 keratinocytes, imparting melanin to the differentiating cells in granules

10

langerhans cells

originate from bone marrow - found in stratum of malpighi (mostly the stratum spinosum) - peripheral dendritic cells == APCs

11

Merkel cells

derived from neural crest - nonencapsulated tactile mechanoreceptors - associated with basal lamina (stratum basale), cytoplasm contains granules, small nerve plate is connected to myelinated axon

light touch, more numerous in thick skin

12

keratinocytes

makes keratin and lamellar granules
form squames in stratum corneum
houses melanin, pigment protein

13

melanin

pigment protein that protects nuclei from UV radiation

14

melanin production

tyrosinase converts tyrosine into DOPA in the presence of UV light
DOPA is polymerized to melanin

15

dermal layers

papillary layer: superficial, loose (areolar) CT - meissner corpuscles and dermal papilla
sub-papillary plexus, capillary branches provide nutrient source
reticular layer: deep, dense irregular CT (type I collagen) - with elastic fibers, more fibers and fewer cells

16

hypodermis

subq tissue
vascular, fat resides here

17

free nerve endings

simple, numerous afferent fibers
dermal-epidermal junction
temperature, touch, itch, pain

18

Meissner Corpuscle

encapsulated
dermal papillae of fingertips, palms, soles
light touch, low frequency

19

Pacinian Corpuscle

CT capsule surrounds 15-50 think, concentric layers
reticular dermis or hypodermis
coarse touch, vibration, pressure

20

merocrine/eccrine gland

exocytosis of apical end cells

21

holocrine glands

disinigration of cell with contents becoming secretion
(cell secretes its w[hol]e body)

22

apocrine gland

membrane enclosed vesicles

23

suderiferous glands

eccrine (merocrine)
acinus- simple cuboidal surrounded by myoepithelial cells
duct - stratified cuboidal epithelium

24

myoepithelial cells

surround an acinus and express its content by squeezing it

25

eccrine sweat glands

found extensively throughout skin
produce sweat used for thermoregulation
components: water, salt, ammonia, uric acid and mucinogen granules

26

apocrine glands

restricted to axilla, circumanal region, areolar
merocrine secretion - milky sweat secretion
responds to hormones and adrenergic (fight of flight) signals

27

sebaceous glands

face, scalp, fair follicles
produce lipid mixture, sebum via holocrine secretion
simple branched acinar
single duct
waxy mix of TAGs and cholesterol - lubricates and waterproofs skin

28

hair shaft

medulla - core
cortex - middle layer
cuticle - outer layer

29

vellus vs terminal hair

vellus = baby hair
terminal = AK chest carpet

30

nails

highly keratinized cells on bed of epidermis
nail root - primal region of plate
nail plate remains attached to nail bed and pushed forward by continous growth
lanula: crescent shaped white area near nail matrix