Structure and Function

Question 1

How much of the population have a skin condiation?

Answer 1

over 25%

Question 2

Is skin the largest vital organ in body?

Answer 2

yes

Question 3

What is the epidermis formed from?

Answer 3

ectoderm

Question 4

What is the dermis formed from?

Answer 4

mesoderm

Question 5

What are pigment producing cells from the neural crest called?

Answer 5

melanocytes

Question 6

Do Blachko’s lines (developmental pattern of skin) follow vessels, nerves or lymph?

Answer 6

NONE

Question 7

What colour is the keratin layer on histology?

Answer 7

pink

Question 8

Which layer is particularly blue on histology?

Answer 8

basal layer

Question 9

What is the order of layers from basal layer upwards?

Answer 9

basal layer, prickle cell, granular, keratin

Question 10

What 3 things control epidermal turnover?

Answer 10

growth factors
cell death
hormones

Question 11

Name 2 conditions where there is a loss of control of epidermal turnover.

Answer 11

psoriasis

cancer

Question 12

Where do keratinocytes migrate from?

Answer 12

basement membrane

Question 13

Which layer is 1 cell thick with small cuboidal cells?

Answer 13

basal layer

Question 14

Which layer is highly metabolically active?

Answer 14

basal layer

Question 15

What type of cells does the prickle cell layer contain?

Answer 15

larger polyhedral cells

Question 16

In which layer are there lots of desmosomes?

Answer 16

prickle cell

Question 17

Which layer has 2-3 layers of flatter cells whose main function is to make keratin?

Answer 17

granular layer

Question 18

Which layer has high lipid?

Answer 18

granular

Question 19

Which layer has odland bodies (lamellar bodies)

Answer 19

granular

Question 20

In which layer are cell nuclei lost?

Answer 20

granular

Question 21

Which layer is the origin of the cornified envelope?

Answer 21

granular

Question 22

Which layer contains corneocytes?

Answer 22

keratin layer

Question 23

Which layer has an insoluble cornified envelope?

Answer 23

keratin

Question 24

Which layer is a tight waterproof barrier?

Answer 24

keratin

Question 25

What release lipid in the keratin layer?

Answer 25

lamellar bodies

Question 26

Give an example of a skin disease where keratinocytes are affected.

Answer 26

HPV infection of keratinocytes leads to warts

Question 27

What plays a key role in epithelial-mesenchymal interactions?

Answer 27

dermo-epidermal junction

Question 28

What are the tree layers of the dermo epidermal junction?

Answer 28

lamina lucida, lamina densa and sublamina densa zone

Question 29

Name some diseases of the dermo epidermal junction

Answer 29

Inherited - epidermolysis bullosa | Acquired - pemphigoid, pemphigus, dermatitis herpetigormitis

Question 30

In what do you see positive immunofluorescnece?

Answer 30

Bullous phemphigoid

Question 31

List 5 cell types found in the dermis.

Answer 31

``` Fibroblasts Macrophages Lymphocytes Langerhans cells Mast cells ```

Question 32

Which of the cell types is found in both epidermis and dermis?

Answer 32

langerhans cells

Question 33

What do fibroblasts do?

Answer 33

secrete collagen

Question 34

Function of macrophages?

Answer 34

scavengers, antigen presentation

Question 35

Function of lymphocytes?

Answer 35

immune reactions

Question 36

Function of langerhans cells?

Answer 36

antigen presentation

Question 37

Function of mast cells?

Answer 37

chemical messengers

Question 38

Describe blood flow in skin blood vessels.

Answer 38

Arteriole to precapillary sphincters to arterial capillaries to venous capillaries to post-capillary venules to collecting venules

Question 39

What is a port wine stain?

Answer 39

Localised overgrowth of blood vessels

Question 40

What are the special nerve receptors in the skin?

Answer 40

Pacinian (pressure) and Meissners (vibration) corpuscles

Question 41

What is the pilosebaceous unit?

Answer 41

sebaceous gland

Question 42

Which type of glands are the largest glands present on face and chest?

Answer 42

sebaceous

Question 43

Which glands Mainly open onto hair follicle | ?

Answer 43

sebaceous

Question 44

Function of sebaceous glands?

Answer 44

control moisture loss | protection from bacterial and fungal infection

Question 45

Sebaceous glands are quiescent pre-puberty, true or false?

Answer 45

Yes - hormone sensitive

Question 46

What do sebaceous glands produce?

Answer 46

sebum: squalene, wax esters, triglycerides and free fatty acids

Question 47

Which glands are present in Axillae and perineum?

Answer 47

apocrine

Question 48

Which glands produce oily fluid/ odour after bacterial decompostion?

Answer 48

apocrine

Question 49

Aprocrine glands are dependant on what?

Answer 49

Androgen

Question 50

Where are eccrine glands found?

Answer 50

Whole skin surface - palms, soles and axillae in particular

Question 51

What is the function of ecrine glands?

Answer 51

cooling by evaporation | moisten palms / soles to aid grip

Question 52

95% of epidermal cells are what?

Answer 52

keratinocytes

Question 53

What do melanocytes produce?

Answer 53

dendritic cells

Question 54

What organelles to melanoycytes contain?

Answer 54

melanosomes

Question 55

What conversion do melanocytes do?

Answer 55

Convert tyrosine to melanin pigment

Question 56

What colour is Eumelanin?

Answer 56

brown or black

Question 57

What colour is Phaeomelanin?

Answer 57

red or yellow

Question 58

What absorbs light?

Answer 58

melanin

Question 59

What form protective cap over nucleus?

Answer 59

melanin caps in basal cells

Question 60

What is an autoimmune disease with loss of melanocytes?

Answer 60

vitiligo

Question 61

Which condition is a genetic partial loss of pigment production?

Answer 61

albinism

Question 62

In what condition is melanin stimulating hormone produced in excess by the pituitary?

Answer 62

Nelson's Syndrome

Question 63

What is a malignant melanoma?

Answer 63

A tumour of the melanocyte cell line

Question 64

Where in the epidermis are Langerhans cells found?

Answer 64

prickle cell layer

Question 65

Where are Merkel cells found?

Answer 65

between keratinocytes & nerve fibres

Question 66

Which rare type of cancer is caused by viral infection and has high mortality?

Answer 66

merkel cells cancer