091614 epidermis

Question 1

layers of epidermis from superficial to deep

Answer 1

stratum corneum
stratum granulosum
stratum spinosum
stratum basale

Question 2

basal stem cells in the epidermis give rise to keratinocytes how?

Answer 2

divide to form one daughter cell and a transient amplifying cell

transient amplif cell will divide a few more times before it moves up into the stratum spinosum

Question 3

what layer makes up most of the epidermis

Answer 3

spinous layer

Question 4

what does the stratum spinosum do?

Answer 4

makes keratin

Question 5

hemidesmosome

Answer 5

connection btwn basal cell and ECM

has keratin intermediate filaments on intracellular side

Question 6

what is the importance of the keratin intermediate filaments in the epidermis

Answer 6

they allow for formation of a network through all the keratinocytes

Question 7

keratin structure

Answer 7

one type I acidic keratin combines with a type II basic keratin to form a heterodimer

heterodimers combine to form tetramers

tetramers are combined to form protofilaments, which then combine to form intermediate filaments

Question 8

true or false: keratin types vary in different locations in the body

Answer 8

true

Question 9

what kinds of granules are the stratum granulosum

Answer 9

keratohyalin granules (filaggrin, involucrin, loricrin)

lamellar granules or Odland bodies (ceramides, cholesterol, fatty acids, hydrolytic enzymes)

Question 10

corneocytes lack what?

Answer 10

nucleus and organelles

Question 11

how are corneocytes held together

Answer 11

corneodesmosomes

Question 12

which sites have no stratum corneum

Answer 12

oral, genital, ocular mucosa

Question 13

which sites have thin cornified layer

Answer 13

face

genitalia

Question 14

how does stratum corneum shed?

Answer 14

by hydrolytic enzymes that were in the lamellar granules of stratum granulosum

Question 15

bricks and mortar

Answer 15

corneocytes have this structure
the bricks are the cornified enveloped of proteins

the mortar is the surrounding lipid envelope

Question 16

pemphigus vulgaris

Answer 16

acquired 
autoimmune bullous (blisters) disease
auto antibodies to desmosomal proteins (desmoglein 1 and 3)

intraepidermal blistering

Question 17

clinical features of pemphigus vulgaris

Answer 17

flaccid, easily ruptured bullae
oral and mucosal lesions
positive NIkolsky’s sign (fragile epidermis so by rubbing, can expand the erosion)

Question 18

treatment for pemphigus vulgaris

Answer 18

prednisone
azathioprine
mycophenolate mofetil
rituximab

Question 19

ichthyosis vulgaris

Answer 19

autosomal dominant genetic condition
mutations in profillaggrin gene (defective filaggrin protein)

1 in 250 ppl affected

Question 20

clinical features of icthyosis vulgaris

Answer 20

fish scales especially on shins
dry skin
hyperlinear palms

Question 21

associations of ichthyosis vulgaris

Answer 21

atopic dermatitis
allergic rhinitis
food allergies
asthma

Question 22

UV-A penetrates what layer of the skin

what does it cause?

Answer 22

dermis

causes tanning and wrinkles

Question 23

which types of UV light can cause cancer?

Answer 23

both UVA and UVB

Question 24

MED

Answer 24

minimal erythemia dose, which is the minimum amt of UVB that causes skin redness at 24 hours