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Y2 Dermatology > Skin Structure and Function > Flashcards

Flashcards in Skin Structure and Function Deck (82)
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1

Embryological origin of the epidermis

Ectoderm
*Think Epidermis Ectoderm*

2

Embryological origin of the dermis

Mesoderm

3

Pattern of growth of skin development follows _______ _____ and rashes which may follow this pattern can be a sign of congenital developmental issues

Blaschko's lines

4

Appendages of the skin may include (4)

Nails
Hair
Mucosae
Glands

5

The epidermis is made of what form of epithelium?

Stratifies squamous epithelium

6

4 main layers of epidermis, in order from top to bottom

1. Keratin layer
2. Granular layer
3. Prickle cell layer
4. Basal cell layer

7

3 cell types which do not originate from the epidermis, but are found there?

1. Melanocytes
2. Langerhans cells
3. Merkel cells

8

4 Features of the Basal Cell layer

1. One cell thick
2. Small cuboidal cells
3. Lots of intermediate keratin filaments
4. Very metabolically active

9

4 Features of the Prickle Cell layer

1. Large polyhedral cells
2. Lots of connecting desmosomes
3. Intermediate filaments connecting the desmosomes
4. cells that evolve and produce proteins

10

4 Features of the Granular Cell layer

1. 2-3 layers of flatter cells
2. keratinohyaline granules containing filaggrin and involucrin
3. high lipid content
4. cell nuclei are lost here

11

4 Features of the Keratin layer

1. lots of overlapping non-nucleated cells
2. Waterproof
3. 80% keratin and filaggrin
4. insensitive to pain

12

Guess the cell type: These cells migrate from the neural crest

Melanocytes

13

Within which layers of the epidermis are melanocytes found?

from the basal layer and above

14

What type of cells are melanocytes?

pigment producing dendritic cells

15

What is the role of melanosomes found within melanocytes?

convert tyrosine to melanin

16

What are the two forms of melanin?

1. Eumelanin
2. Phaeomelanin

17

Describe eumelanin

brown or black melanin with protective function. it is found in hair

18

Describe phaeomelanin

red or yellow melanin

19

How do melanocytes protect the keratinocytes?

The melanosomes migrate to the dendrites of the melanocyte and provide a protective kap over the nucleus of the keratinocyte.

20

What is a mole?

A nest of melanocytes

21

Where are merkel cells found?

The basal layer between keratinocytes and nerve fibres; they are ubiquitous

22

Function of Merkel Cells

Mechanoreceptors

23

What is the origin of Langerhans cells?

Bone marrow

24

Where are Langerhans cells found?

From the Prickle cell layer and above, the dermis and the lymph nodes

25

Function of Langerhans cells

Aid the skin immune system by acting as APCs

26

**What feature is unique to Langerhans cells?**

**Racket organelles which contain birbeck granules**
This is a common exam question

27

How does the hair follicle develop?

Initially grows through an epidermal component and then down into the dermis to develop a dermal papilla

28

Where does pigmentation come from in hair?

melanocytes above the dermal papilla

29

Where does the hair follicle develop? (embryologically)

ectoderm

30

Phases of hair growth (3)

Anagen
Catagen
Telogen