Skin Structure and Function

Question 1

What are the 2 layers of the skin?

Answer 1

Epidermis and Dermis

Question 2

Which layer is the outer layer?

Answer 2

Epidermis

Question 3

Where is the dermis?

Answer 3

Beneath the epidermis

Question 4

What is the epidermis made up of?

Answer 4

Stratified squamous epithelium (1.5mm thick)

95% keratinocytes

Question 5

What is the dermis made up of?

Answer 5

Connective tissue

Question 6

Where does the epidermis originate?

Answer 6

Ectoderm cells form single layer periderm, gradual increase in layers of cells, periderm cells cast off

Question 7

Where does the dermis originate from?

Answer 7

Formed from mesoderm below ectoderm

Question 8

Where do the melanocytes originate from?

Answer 8

Pigment producing cells from neural crest

Question 9

What are Blaschko’s lines?

Answer 9

Developmental growth patten of skin (don’t follow vessels, nerves or lymphatics)

Question 10

What are the layers of the epidermis?

Answer 10

Keratin layer, granular layer, prickle cell layer, basal layer

Question 11

What makes the skin of the palms and soles different?

Answer 11

Thicker keratin layer

Question 12

Where does HPV affect?

Answer 12

Keratinocytes, wouldn’t survive inside due to 37 degree temperature

Question 13

What type of cells are melanocytes?

Answer 13

Pigment producing dendritic cells

Question 14

What are melanocyte organelles called?

Answer 14

Melanosomes

Question 15

What do melanocytes convert into melanin?

Answer 15

Tyrosine

Question 16

What is the brown/black pigment called?

Answer 16

Eumelanin

Question 17

What is the red/yellow pigment called?

Answer 17

Phaeomelanin

Question 18

What do melanin caps do?

Answer 18

Protect the nuclear DNA In basal cells

Question 19

What is vitiligo?

Answer 19

An autoimmune condition which involves melanocytes being attacked by cytotoxic T cells, usually self-limiting

Question 20

What is albinism?

Answer 20

genetic partial loss of pigment production

Question 21

What is nelson’s syndrome?

Answer 21

Melanin stimulating hormone is produced in excess by the pituitary

Question 22

Where do langerhan cells originate?

Answer 22

Mesenchymal origin-bone marrow
Prickle cell layer
Dermis and lymph nodes

Question 23

Where are Merkel cells?

Answer 23

Basal cell layer

Between keratinocytes and nerve fibres

Question 24

What are Merkel cells?

Answer 24

Mechanoreceptors

Question 25

Is Merkel cell cancer common or rare?

Answer 25

Rare

Question 26

What causes Merkel cell cancer?

Answer 26

Viral infection

Question 27

What is anagen phase?

Answer 27

Growing

Question 28

What is catagen phase?

Answer 28

Involuting

Question 29

What is telogen phase?

Answer 29

Resting

Question 30

Growth rate of nail a day?

Answer 30

0.1mm

Question 31

What is the demo-epidermal junction? (also known as basement membrane)

Answer 31

Interface between epidermis and dermis

Question 32

What is bullous pemphigoid?

Answer 32

Antibody formed by immune cells against the DEJ

Question 33

What is epidermolysis bullosa?

Answer 33

Defects in proteins that make DEJ

Question 34

What is chronic lymphoedema?

Answer 34

Enlarged lymphatic channels

Question 35

What is the consequence of chronic lymphoedema?

Answer 35

Recurrent episodes of cellulitis (bacteria in the dermis)

Question 36

What can be used to treat chronic lymphedema?

Answer 36

Moisturisation and compression socks

Question 37

What do pacinian receptors detect?

Answer 37

Pressure

Question 38

What do meissners receptors detect?

Answer 38

Vibration

Question 39

What is neurofibromatosis?

Answer 39

Benign tumours caused by overgrown nerves

Question 40

What does the pilosebaceous unit consist of?

Answer 40

Hair follicle, hair shaft, arrestor pili muscle and sebaceous glands

Question 41

What is hirsutism?

Answer 41

Excess hair in inappropriate places

Question 42

what is the cross section shape of asian hair

Answer 42

round

Question 43

what type of hair has the fastest growth rate

Answer 43

asian

Question 44

what is the shape of African hair cross section

Answer 44

ellipsoidal

Question 45

what type of hair grows slowest

Answer 45

african

Question 46

what is the cross section shape of caucasian hair

Answer 46

round/oval

Question 47

what type of hair has the lowest density

Answer 47

african

Question 48

what type of hair has the highest density

Answer 48

caucasian

Question 49

what hormonal influences can affect hair growth

Answer 49

thyroxine, androgens, menopause (less oestrogen)

Question 50

what can cause hirsutism

Answer 50

physiological, androgens, PCOS, tumour

Question 51

what are the three skin glands

Answer 51

sebaceous, apocrine, eccrine

Question 52

what do sebaceous glands do

Answer 52

produce sebum

Question 53

what do apocrine glands do

Answer 53

discharge into hair follicle, maybe involved in sex hormones

Question 54

what do eccrine glands do

Answer 54

sweat glands, thermoregulation

Question 55

when do sebaceous glands start to become active

Answer 55

puberty

Question 56

where are the largest sebaceous glands

Answer 56

face and chest

Question 57

what is the function of sebum

Answer 57

control moisture loss and protect against fungal infections

Question 58

what can too much sebum lead to

Answer 58

acne

Question 59

what do apocrine sweat glands develop as part of

Answer 59

pilosebaceous unit

Question 60

what is apocrine glands dependent on

Answer 60

androgens

Question 61

what supplies eccrine glands

Answer 61

sympathetic cholinergic nerve