Skin structure & function

Question 1

What are the layers of the epidermis?

Answer 1

Keratin layer
Granular layer
Prickle cell layer
Basal layer

Question 2

What are Blaschko’s lines?

Answer 2

Developmental growth pattern of skin (not following vessels, nerves, lymphatics)

Question 3

Which cells migrate from neural crest?

Answer 3

Melanocytes

Question 4

What type of cells are melanocytes?

Answer 4

dendritic cells

Question 5

What substance do melanocytes convert to melanin pigment?

Answer 5

tyrosine

Question 6

What are the two types of melanin pigment?

Answer 6

Eumelanin

Phaeomelann

Question 7

What is vitiligo?

Answer 7

autoimmune dsease with loss of melanocyes

Question 8

What is a malignant melanoma?

Answer 8

tumour of the melanocyte cell line

Question 9

Where are Langerhan cells found?

Answer 9

PCL
Derms
Lymph nodes

Question 10

Wha is the role of Langerhan cells n the immune system?

Answer 10

Antigen presenting cells

pick up anten in skin and circulate to lymph nodes via lymphatic system

Question 11

Where are Merkel cells found?

Answer 11

Basal layer tween keratinocyes and nerve fibresbe

Question 12

which gland is found adjacent to hair follice?

Answer 12

sebaceous gland

Question 13

What are the three phases of hair growth?

Answer 13

Anagen (growing)
Catagen (involuting)
Teloen (resting)

Question 14

What factors influence hair growth?

Answer 14

hormonal influences e.g. thyroxine, androgens

Question 15

What diseases can affec he DEJ?

Answer 15

inherited skin fragility (mutation of protein in DEJ)

Acquired autoantibodies to protein in DEJ (pemphigus, pemphigoid, herpetiformis)

Question 16

What is immunofluorescence used to test for?

Answer 16

Bullous pemphigoid

Question 17

What cell types are found in the dermis?

Answer 17

fibroblasts, macrophages, mast cells, lymphocytes

Question 18

Whatis the role of fibroblasts in the dermis?

Answer 18

secrete collaen

Question 19

What is the role of macreophages in he dermis?

Answer 19

Scavengers (antigen presentation)

Question 20

Role of lymphocytes in dermis?

Answer 20

immune reactions

Question 21

Role of lanerhan cells in the dermis (they are also in he epidermis)?

Answer 21

antigen presenation

Question 22

Role of mast cells in the dermis?

Answer 22

chemical messengers

Question 23

What is a port wine stain?

Answer 23

capillary or cavernous haemangioma

Question 24

Which nerve cell receptors detect pressure?

Answer 24

Pacinian corpuscles

Question 25

Whcih nerve cell receptors detec vibration?

Answer 25

Meissners corpuscles

Question 26

Where are sebaceous glands found?

Answer 26

face and chest

Question 27

What do sebaceous glands produce?

Answer 27

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

Question 28

What is the function of sebaceous glands?

Answer 28

control moisture loss

protection from bacterial and fungal infection

Question 29

Where are apocrine lands mainly found?

Answer 29

Armpits

Question 30

What do apocrine glands produce?

Answer 30

oily f;uid - odour after bacterial decomposition

Question 31

What are apocrine glands dependent on?

Answer 31

androgen

Question 32

Where are eccrine glands found?

Answer 32

whole skin surface (palms, soles and axillae in particular)

Question 33

What nerves supply eccrine glands?

Answer 33

Sympahetic cholinergic nerve supply

Question 34

Function of eccrine glands?

Answer 34

cooling by evaporaion

moisten palms. soles to add grip

Question 35

Functions of the skin

Answer 35

barrier
metabolism & deoxification
thermoregulation
immune defence
communication
sensory function

Question 36

What is convered to Vit D by UV light?

Answer 36

cholicalcerferol

Question 37

How is Vit D3 stored?

Answer 37

stored as hydroxycholecalciferol in liver