skin review deck

Question 1

what is the embryologic origin of epidermis? dermis?

Answer 1

epidermis- ectoderm

dermis- mesoderm

Question 2

what layer is present in thick skin, but absent in thin skin?

Answer 2

stratum lucidum

Question 3

where are hair follicles absent?

Answer 3

thick skin

Question 4

describe eecrine sweat glands

Answer 4

open to skin surface via ducts
ducts are dark, secretory portion light
merocrine secretion
clear/isotonic liquid

Question 5

describe apocrine sweat glands

Answer 5

open into hair follicle
merocrine secretion
more concentrated in groin/axilla
cloudy/odorous secretion

Question 6

what is the “malphagian” layer?

Answer 6

stratum basale + stratum spinosum

Question 7

what is meant by “germanitivum”?

Answer 7

another term used for s. basal- ability to amplify, divide and differentiate

Question 8

pemphigus vulgaris

Answer 8

autoimmune destruction of desmosome attachments in stratum spinosum, leads to erosion and ulceration

Question 9

what is contained in keratohyalin granules?

Answer 9

profillagrin, loracrin, involucrin, cornifen –> all in granules in the stratum granulosum to help cells proceed to stratum corneum

Question 10

what surrounds cells in stratum corneum?

Answer 10

lipid rich membrane with keratin and filaggrin

Question 11

what are lamellar bodies in skin?

Answer 11

impermeable, lipid containing membrane that provides impermeability to water

Question 12

where are nerves and blood vessels in the skin most prominent?

Answer 12

dermal-hypodermal interface

Question 13

what is the origin of melanocytes?

Answer 13

neural crest cell

Question 14

what is the mode of secretion for melanosomes? describe it

Answer 14

cytocrine- part is bitten off and engulfed by adjacent cells

Question 15

where is the connective tissue portion of the hair sheath derived?

Answer 15

dermis

Question 16

what is the “germinal matrix”?

Answer 16

=nail root

Question 17

where are nerves, lymph and bv in the nail?

Answer 17

root

Question 18

what is the m/c cell type in the dermis?

Answer 18

fibroblasts

Question 19

what are the major components of hypodermis?

Answer 19

GAGs, fibroblasts, dendrite cells, mast cells, b/t cells, adipose cells

Question 20

where are prickle cells located?

Answer 20

keratinocytes in stratum spinosum

Question 21

what do keratinocytes produce?

Answer 21

cytokines
prostaglandins
antioxidants
platelet and fibroblast stimulating factors
vit D3

Question 22

albanism

Answer 22

caused by tyrosinase deficiency (converts tyrosine to melanin)

Question 23

from where are langerhan cell derived?

Answer 23

bone marrow, from monocytes

Question 24

what is the action of langerhan cells?

Answer 24

they are APCs, detect antivenin dermis, travel to blood/lymph, travel to LN, activates T cells

Question 25

contact dermatitis

Answer 25

caused by a defect in langerhan cells

Question 26

what are “Bilbeck” ganules?

Answer 26

tennis racket granules in langerhan cells

Question 27

epidermolysis bullosa

Answer 27

in kids, dysfunction of hemidesmosomes

Question 28

bullous pemphigoid

Answer 28

autoimmune destruction of basement membrane

Question 29

what are the hair phases?

Answer 29

anagen- growth
catagen- inolution
telogen- resting

Question 30

where are pacinian corpuscles found? concentrated?

Answer 30

found in hyperdermis, concentrated in palms and soles

Question 31

from what is the hair follicle derived?

Answer 31

tubular invagination of the epidermis

Question 32

what shape are the cells in stratum basal? stratum spinosum?

Answer 32

basale- columnar

spinosum- polygonal

Question 33

what organelle produces melanin?

Answer 33

melanosomes in melanocytes

Question 34

what is the structural different between phaeomelanin and eumelanin?

Answer 34

phaeomelanin is more sulfated

Question 35

where are hair follicles necessary?

Answer 35

eyelashes

Question 36

what composes the pilosebaceous unit?

Answer 36

hair + sebaceous gland + arector pili mm