20 - Introduction to Skin

Question 1

Most common reason for visiting the GP

Answer 1

Skin disorders

Question 2

Functions of skin

Answer 2

Protection
Insulation
Sensory information
Vitamin D synthesis

Question 3

Major cell type of the epidermis

Answer 3

Keratinocytes

Question 4

What type of cell are in the Epidermis

Answer 4

Stratified Squamous Epithelium

Question 5

4 layers of the epidermis

Answer 5

Stratum Corneum 
Stratum Granulosum
Stratum Spinosum
Stratum Basale
(Come Get Sun Burnt)

Question 6

Function of keratinocyte

Answer 6

Produce keratins

Responsible for cells structural integrity and resillience

Question 7

Where are keratins most abundant

Answer 7

Stratum corneum
Hair
Nails

Question 8

A type keratin

Answer 8

More flexible
Soft
In hair

Question 9

B type keratin

Answer 9

Harder
In nails
More rigid

Question 10

What defines the two types of keratins

Answer 10

Secondary structure

S-S bonding

Question 11

What do keratins exist as

Answer 11

Acid-basic pairs

e.g K5/K14

Question 12

In what layer does proliferation occur in the epidermis

Answer 12

Basal layer

Question 13

What does the basal membrane consist of

Answer 13

Laminin 332
Collagen IV
Collagen VII

Question 14

What do cells attach to in the basal membrane

Answer 14

Laminin 332

Question 15

What is the function of collagen VII in the basal membrane

Answer 15

Mechanical anchorage to the dermis

Question 16

Function of hemidesmosomes

Answer 16

Link keratin cytoskeleton to basal membrane

Question 17

Cells in stratum spinosum

Answer 17

3-4 cells thick

Numerous desmosomes

Question 18

Cells in stratum granulosum

Answer 18

2-3 cells thick
Large granules of keratohyalin
Filaggrin
Involucrin
Loricrin

Question 19

Function of stratum corneum

Answer 19

Protective barrier

Question 20

structure of stratum corneum

Answer 20

Thick cornified envelope

Cross linked by enzymes

Question 21

Adherens junctions

Answer 21

Cadherin receptor linked to actin cytoskeleton

Question 22

Desmosome

Answer 22

Cadherin receptor linked to keratin cytoskeleton

Question 23

Tight junctions

Answer 23

Claudin and occludin seal intercellular space

Question 24

Gap junction

Answer 24

Intercellular pores made up of connexins (allow to transport nutrients from one cell to another

Question 25

Layers of the dermis

Answer 25

Papillary Reticular Adipose

Question 26

Most abundant cell in dermis

Answer 26

Fibroblast

Question 27

What do fibroblasts synthesise

Answer 27

Collagen Elastin Proteoglycans

Question 28

Papillary layer

Answer 28

Directly beneath the epidermis and BM | Blood capillaries

Question 29

Why is the papillary layer more elastic

Answer 29

TII collagen and Elastin | Randomly oriented, fine collagen

Question 30

Reticular layer

Answer 30

Larger, more organised collagen densely packed gives skin high tensile strength

Question 31

What does the pilosebaceous unit comprise of

Answer 31

Hair follicle | Sebaceous gland

Question 32

What layer of skin is the hair follicle from

Answer 32

Epidermis

Question 33

Two types of hair

Answer 33

Vellus - body hair | Terminal - Scalp + secondary sexual hair

Question 34

What produces hair

Answer 34

Matrix keratinocytes

Question 35

What controls hair growth and where is it

Answer 35

Dermal papilla fibroblasts | IN THE DERMIS

Question 36

Function of erector pilli muscle

Answer 36

Movement of the hair

Question 37

Where are hair follicle stem cells located

Answer 37

Bulge region | Express keratin 15

Question 38

Phases of the hair cycle

Answer 38

Anagen - Active Catagen - Regressive Telogen - Resting

Question 39

What is the sebaceous gland

Answer 39

Androgen sensitive exocrine gland Releases sebum Infection --> acne

Question 40

Components of eccrine sweat gland

Answer 40

Excretory duct | Secretory coil

Question 41

What is the apocrine gland

Answer 41

Sweat gland associated with hair follicles

Question 42

Where are apocrine glands found

Answer 42

Axilla | Pubic region

Question 43

What type of cell are melanocytes

Answer 43

Dendritic cells

Question 44

Where are melanocytes found

Answer 44

Epidermis on BM and hair matrix

Question 45

Function of melanocytes

Answer 45

produce melanin in melanosomes

Question 46

Eumelanin

Answer 46

More common Black or brown

Question 47

Pheomelanin

Answer 47

Reddish colour

Question 48

What are langerhans cells

Answer 48

Dendritic cells presents antigens to t lymphocytes first line of defence

Question 49

Where are langerhans found

Answer 49

Basal and spinous layers

Question 50

Where are Merkel cells found

Answer 50

Stratum basale

Question 51

Function of merkel cells

Answer 51

Sensory perception

Question 52

Function of mast cell

Answer 52

Immune response - secretes histamine

Question 53

Wound healing stages

Answer 53

1) Inflammation 2) Proliferation - active growth and repair 3) Maturation - remodelling