Lecture 17:skin/eyes/household Toxicants

Front 1

skin functions (7)

Back 1

barrier
thermal regulation
immune function
sweating
metabolic function
sensory
hormonal functions

Front 2

3 layers of skin

Back 2

epidermis(contains stratum corneum the very surface of skin)
dermis(major structures)
subcutaneous(fat cells/vascular system)

Front 3

bottome of epidermis contains (2 words)

Back 3

basal cells(stem cells that produce new cells)

Front 4

keratinocytes are cells of the ____ and live for ____

Back 4

epidermis; 4 weeks

Front 5

As keratinocytes move up they flatten and form _____ (2 words)

Back 5

granular layer

Front 6

stratum corneum is mainly made up off _____ (2 words)

Back 6

dead cells

Front 7

the shedding of skin at surface is a ____ function

Back 7

protective because cells turn over quickly all the time

Front 8

what are desmosomes?

Back 8

attachments between corneocytes (flatted cells at surface) that hold them together

Front 9

whats purpose of lipids between desmosomes

Back 9

to conserve moisture they dont let water pass

Front 10

stratum corneum varies in thickness its thickest in _____ (2) and thinnest in ____ (1)

Back 10

palms/soles of feet ; behind ear

Front 11

anterio-venus shunts

Back 11

how the skin thermoregulates. Dilation= increased blood flow therefore more heat
ANS also control this
can be reaction to some drugs

Front 12

stratum corneum can be impaired by (3)

Back 12

increased water content,abrasion,skin disease

Front 13

toxicants are more readily absorbed if they are ____(2)

Back 13

low molecular weight;high lipid solubility

Front 14

routes of entry thru skin

Back 14

intercellular
transcellular
sweat glands
hair follicles
hair shaft

Front 15

is there first pass effect in skin

Back 15

yes it contains P450 in dermis,lower epidermis and follicle and also contains phase 2 enzymes

Front 16

pilosebaceous unit

Back 16

hair follicle

Front 17

inflammation of skin also called

Back 17

contact dermatitis

Front 18

irritant dermatitis is combination of (2)

Back 18

primary irritants and sensitizers

Front 19

primary irritant

Back 19

causes damage at site of contact

Front 20

absolute irritant

Back 20

SA/SB or reactive chemical severe inflammation upon exposure

Front 21

an example of irritant dermatitis

Back 21

cement when wet very alkaline=cement burns
takes while to feel needs to get deep

Front 22

contact allergic dermatitis involves what type of reactions

Back 22

type 4 cell-mediated hypersensitivity reactions

Front 23

langerhans cells

Back 23

in the skin part of immune system and produce antigens

Front 24

hapten

Back 24

is a immunological stimulant (formed when a molecule after exposure binds to protein)

Front 25

describe allergic dermatitis

Back 25

1)first exposure langerhans cells send message to Tcells,T cells now sensitized
2)T cells enter lymphatic vessels and go to lymph nodes and multiply =hyperplasia
3)sensitized t cells chills in dermis/epidermis
4)second exposure causes cellmediated immune reaction
5)no antibodies involved inly cells,tagets killed by T cells/lymphokines
6)severe injury caused

Front 26

catechol molecule

Back 26

hapten in poison ivy/oak

Front 27

type 4 hypersensitivity reactions

Back 27

poison ivy,airborne allergens,nickel,neomycin (topical antibiotic),

Front 28

Patch Test

Back 28

tests for what causing dermatitis

Front 29

buhler test/local lymph node assay

Back 29

used in guinea pigs/mice apply compound to ear an see what happens in local lymph node

Front 30

phototoxicology

Back 30

light and drugs

Front 31

UVA vs UVB

Back 31

UVA: penetrates deeper and more exposure
UVB:more harmful but exposure is variable

Front 32

photoaging

Back 32

wrinkles in skin from smoking/sunlight

Front 33

when light plus drug get (3)

Back 33

phototoxixity,photocarcinogenicity, photoallergy

Front 34

furocoumarins

Back 34

chemical in limes causes phototoxicity

Front 35

tetracyclines,chloropromazine,various plants

Back 35

cause phototoxicity

Front 36

EPARS

Back 36

phototoxicity screening assay in reconstituted skin

Front 37

photocarcinogenicity

Back 37

xeniobiotic (compound penetrating skin) absorbs UV and makes free radical

Front 38

Xeniobiotic+UVA=

Back 38

DNA adduct

Front 39

photoallergy involves

Back 39

xeniobiotic absorbing UV light and becoming hapten get type 4 reaction

Front 40

urticaria (hives) is a ____ reaction

Back 40

type1 (anaphylactic)

Front 41

is type1 systemic

Back 41

no,its localized

Front 42

explain type 1 mechanism

Back 42

first exposure allergen stimulates B cells these make IgE antibody.
not everyone make IgE
IgE binds to mast cells/other things
second exposure antigen crosslinks antibody on mast cells
then when allergenbinds to bound IgE causes mast cells to degranulate(dumps out chemicals) Also activates phospholipase/localizedinflammatory rxn's thru COX and lipooxygenase

Front 43

cox makes _______(2)
lipooxygenase makes _____(1)

Back 43

prostaglandins/thromboxane;leukotrienes

Front 44

draize test

Back 44

for eye toxicology

Front 45

apamine

Back 45

in bee stings
is a mast cell degranulator
thereleased histamine dilates vessels (red area) stimulates nerve ending(pain)