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Flashcards in Skin Structure and Function Deck (34)
1

About 80-85% of dermis is

type I collagen
thick, dense for support and bulk

2

Type of collagen in papillary layer

type III collagen

3

Specialized cells in epidermis

-keratinocytes
-melanocytes
-langerhans cells
-merkel cells

4

3 factors influence skin color

-melanocytes
-hemoglobin
-carotenes

5

Keratinocyte growth and differentiation is regulated by

-Calcium second messengers
-immunomodulatory cytokines

6

K1 and K10 synthesized in which epidermal layer

stratum spinosum

7

Loricin is produced in the

stratum spinosum

8

Tonofibrils are characteristic of which epidermal layer

stratum spinosum

9

Keratohyalin granules contribute

structural proteins
(synthesize and store profilaggrin)

10

Transglutaminase is activated in the _________ layer as what happens?

granular
cells become more permeable to calcium

11

How does stratum corneum function as a barrier to permeability?

Controlling the:
-loss of fluid
-penetration of noxious foreign materials/radiation

12

_________ of keratin chains allows them to coil around one another to form a protofibril

heptad repeat structure

13

Apparent function of keratins in epithelial cells

provide structural framework by connecting desmosomes

14

Epidermal proteins in keratohyalin granules

Filaggrin, Loricrin, Involucrin

15

Filaggrin is rich in

histidine

16

Filaggrin dissociates from keratin when

the arginine side chain is converted to citrulline in lower stratum corneum

17

Epidermal protein that is a transglutaminase substrate

involucrin

18

Involucrin is synthesized in

stratum spinosum

19

Involucrin becomes cross-linked in the ______ layer

granular

20

Sulfur-rich protein in keratohyalin granules

Loricrin

21

Cornified cell envelope is surrounded by ________

covalently bound lipid layer of ceramides and fatty acids

22

Key regulatory mechanisms of keratinocyte proliferation/differentiation

-Nuclear hormone receptors
-calcium second messenger signaling
-immunomodulatory regulation
-cytokines and growth factors

23

Elias' studies of calcium effects on skin found that:
-Acute barrier disruption causes ________
^ which coincides with _________
Exposure to high Ca+led to _________

-reduced Ca+ in the stratum granulosum
-lamellar body secretion, decreased mRNAs for differentiation specific proteins
-restoration of mRNAs for differentiation specific proteins

24

external calcium activates __________ which leads to the activation of _________

CaR
PLC

25

Second messengers in calcium regulation of keratinocyte differentiation

-IP3
-DAG

26

IP3 stimulates

release of calcium from intracellular stores

27

__________ enhances the cellular response to calcium

-Vitamin D

28

Three proteins regulated by AP-1 transcription factor

Involucrin, Loricrin, Transglutaminase

29

Protein Kinase C is activated by

increase in DAG and Cai

30

PKC activates _______

AP-1 family of nuclear transcription factors (genes encoding differentiation specific proteins)

31

Inflammatory processes involve
-Angiogenesis:
-Influx of what?

-multiplying, leaky blood vessels
-Neutrophil/eosinophil & their inflammatory mediators

32

Two cytokines produced upon disruption of barrier with irritants like surfactants

-TNF-a
-IL-1a

33

Th1 are involved with

IL-2
IFN-y
Psoriasis

34

Th2 are involved with

IL-4, IL-5
Atopic Dermititis