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Flashcards in Skin Structure and Function Deck (34)
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1
Q

About 80-85% of dermis is

A

type I collagen

thick, dense for support and bulk

2
Q

Type of collagen in papillary layer

A

type III collagen

3
Q

Specialized cells in epidermis

A
  • keratinocytes
  • melanocytes
  • langerhans cells
  • merkel cells
4
Q

3 factors influence skin color

A
  • melanocytes
  • hemoglobin
  • carotenes
5
Q

Keratinocyte growth and differentiation is regulated by

A
  • Calcium second messengers

- immunomodulatory cytokines

6
Q

K1 and K10 synthesized in which epidermal layer

A

stratum spinosum

7
Q

Loricin is produced in the

A

stratum spinosum

8
Q

Tonofibrils are characteristic of which epidermal layer

A

stratum spinosum

9
Q

Keratohyalin granules contribute

A
structural proteins 
(synthesize and store profilaggrin)
10
Q

Transglutaminase is activated in the _________ layer as what happens?

A

granular

cells become more permeable to calcium

11
Q

How does stratum corneum function as a barrier to permeability?

A

Controlling the:

  • loss of fluid
  • penetration of noxious foreign materials/radiation
12
Q

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

A

heptad repeat structure

13
Q

Apparent function of keratins in epithelial cells

A

provide structural framework by connecting desmosomes

14
Q

Epidermal proteins in keratohyalin granules

A

Filaggrin, Loricrin, Involucrin

15
Q

Filaggrin is rich in

A

histidine

16
Q

Filaggrin dissociates from keratin when

A

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

17
Q

Epidermal protein that is a transglutaminase substrate

A

involucrin

18
Q

Involucrin is synthesized in

A

stratum spinosum

19
Q

Involucrin becomes cross-linked in the ______ layer

A

granular

20
Q

Sulfur-rich protein in keratohyalin granules

A

Loricrin

21
Q

Cornified cell envelope is surrounded by ________

A

covalently bound lipid layer of ceramides and fatty acids

22
Q

Key regulatory mechanisms of keratinocyte proliferation/differentiation

A
  • Nuclear hormone receptors
  • calcium second messenger signaling
  • immunomodulatory regulation
  • cytokines and growth factors
23
Q

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

A
  • reduced Ca+ in the stratum granulosum
  • lamellar body secretion, decreased mRNAs for differentiation specific proteins
  • restoration of mRNAs for differentiation specific proteins
24
Q

external calcium activates __________ which leads to the activation of _________

A

CaR

PLC

25
Q

Second messengers in calcium regulation of keratinocyte differentiation

A
  • IP3

- DAG

26
Q

IP3 stimulates

A

release of calcium from intracellular stores

27
Q

__________ enhances the cellular response to calcium

A

-Vitamin D

28
Q

Three proteins regulated by AP-1 transcription factor

A

Involucrin, Loricrin, Transglutaminase

29
Q

Protein Kinase C is activated by

A

increase in DAG and Cai

30
Q

PKC activates _______

A

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

31
Q

Inflammatory processes involve

  • Angiogenesis:
  • Influx of what?
A
  • multiplying, leaky blood vessels

- Neutrophil/eosinophil & their inflammatory mediators

32
Q

Two cytokines produced upon disruption of barrier with irritants like surfactants

A
  • TNF-a

- IL-1a

33
Q

Th1 are involved with

A

IL-2
IFN-y
Psoriasis

34
Q

Th2 are involved with

A

IL-4, IL-5

Atopic Dermititis