Skin Structure and Function 1 Flashcards Preview

2nd Year - Dermatology > Skin Structure and Function 1 > Flashcards

Flashcards in Skin Structure and Function 1 Deck (45):
1

What are the 5 components of skin in mammals?

Epidermis
Dermo-epidermal junction
Dermis
Sub-cutis
Appendages

2

What layer of the skin makes up the epithelium?

Epidermis

3

What type of epithelium is the epidermis?

Stratified squamous epithelium

4

Is the epidermis or dermis more cellular?

Epidermis

5

What of the 4 basic tissue types is the dermis?

Connective tissue

6

What is the sub-cutis mainly composed of?

Fat

7

What are the 4 skin appendages?

Nails
Hair
Glands
Mucosae

8

What type of epithelium lines the blood vessels?

Simple squamous epithelium

9

Where is glandular epithelium found in the skin?

In sweat and sebaceous glands

10

What is the periderm?
When does this generally disappear?

Outer layer of the bilaminar foetal epidermis
Before birth

11

What does the epidermis form from in the embryo?

Ectoderm cells form a single layer of periderm
There is a gradual increase in layers of cells before the periderm is cast off

12

What is the ectoderm?

One of 3 primary germ layers in the very early embryo

13

What is the embryonic origin of the dermis?

Mesoderm

14

What is the neural crest?

A temporary group of cells unique to vertebrates that arise from the embryonic ectoderm cell layer and in turn give rise to a diverse cell lineage

15

What is the embryonic origin of melanocytes?

Neural crest

16

At 4 weeks, what layers is the skin made up of? (3)

Periderm
Basal layer
Dermis (corium)

17

At 16 weeks, what layers is the skin made up of? (5)

Keratin Layer
Granular layer
Prickle ell Layer
Basal Layer
Dermis

18

At how many weeks is the skin fully formed with appendages?

26 weeks

19

What is the basal layer formed from?

Basal keratinocyte cells ("Stem cells of the skin") and melanocytes

20

What "lines" show the developmental growth pattern of skin?

Blaschko's lines - don't follow vessels, nerves or lymphatics

21

What forms the basement membrane of the epithelium (epidermis)?

the demo-epidermal junction

22

How thick is the epidermis?

Very thin - 1.5mm thick

23

What cells make up 95% of the epidermis?

Keratinocytes

24

what structural protein does keratinocytes contain?

Keratin

25

Apart from keratinocytes, what other cells does the epidermis contain? (3)

Melanocytes
Langerhans cells
Merkel cells

26

What are melanocytes?

Melanin producing cells

27

What are lagerhans cells?

Dendritic cells

28

What are merkel cells?

Mechanoreceptors

29

What are the 4 layers of the epidermis with their Latin name?

Keratin layer (stratum corneum)
Granular layer (stratum granulosum)
Prickle cell layer (stratum spinosum)
Basal layer (stratum basale/ germinativum)

30

How many cells thick is the basal layer generally?

1 cell thick

31

What is the ratio of melanocytes to basal cells in the basal layer?

1:10

32

what do basal cells contain lots of?

intermediate filaments - parts of the cytoskeleton

33

What shape are prickle cells?

Polyhedral

34

What does the pricked cell layer have lots of between cells?

Desmosomes (connections)

35

How many layers of cells does the granular layer have?

2-3 layers of flatter cells

36

What type of cells make up the granular layer of the skin?

Keratinocytes known as granular cells

37

What do granular cells contain? (2)

Large keratohyalin granules
Odland bodies

38

What 2 things are contained within the large keratohyalin granules of granular cells?

Filagrrin
Involucrin proteins

39

What are odland bodies?
Other name for these?

A type of epithelial organelle with a high lipid content
Lamellar bodies

40

What cells make up the keratin layer?
What are these?

Corneocytes
Type of terminally differentiated keratinocyte that is non-nucleated

41

What is the name for the outer part of a corneocyte that makes up the outer layer of the epidermis?

Cornified envelope - made from keratin

42

What creates the tight waterproof barrier of the keratin layer?

Lamellar granules release lipid

43

Where are keratinocytes produced?

in the basal layer

44

What controls the balance between cells in/ out e.g. keratinocyte production at the basal layer? (3)
What 2 conditions are caused by a loss in this control?

Growth factors
Hormones
Cell death
Skin cancer
Psoriasis

45

What causes white plaques in the oral mucosa?

Thickening of the oral epidermis