General

Question 1

Functions of skin

Answer 1

Barrier to infection
Thermoregulation
Protection against trauma
Protection against UV
Vitamin D synthesis
Regulate H2O loss

Question 2

In which layer does normal proliferation of the skin occur

Answer 2

Basal layer

Question 3

Describe renewal of skin

Answer 3

Balance between introduction of new cells from basal layer of epidermis and shedding of mature corneocytes at surface of stratum corneum

Question 4

What is the name of the process where mature corneocytes are shed from the surface of the stratum corneum

Answer 4

Desquamation

Involves degradation of extracellular corneo-desmosomes under the action of protease enzymes

Question 5

Normal pH of the skin (and purpose of it being that)

Answer 5

5.5 (allows proteases to remain on the skin thereby enabling the balance of new cells from the basal layers of the epidermis)

Question 6

3 layers of skin

Answer 6

Epidermis (most superficial)
Dermis
Subcutaneous tissue (fat)

Question 7

5 Sub-layers of epidermis

Answer 7

Stratum corneum
Stratum lucidum
Stratum granulosum
Stratum spinous
Stratum basale (dividing cells)

Question 8

Describe structure of Stratum corneum

Answer 8

Layer of Keratin, made up of corneo-desmosomes and desmosomes:
Corneocytes (like bricks)
Surrounded by lipid lamellae (like cement) connected by corneodesmosomes (like iron rods for extra stability)

Question 9

Give example of diseases with increased numbers of corneodesmosomes

Answer 9

Psoriasis

Thickening of stratum corneum

Question 10

Give example of disease with decreased number of corneo-desmosomes

Answer 10

Atopic eczema

Thinning of the stratum corneum - therefore increased risk of inflammation

Question 11

Give examples of 2 corpuscles in dermis and functions

Answer 11

Meissner’s corpuscle - light touch

Pacinian corpuscle - coarse touch/vibration

Question 12

Give examples of specialised structures found in skin layer

Answer 12

Nerves - sensory nerve endings in epidermis
Sweat glands
Sebaceous gland and Hair cell
Arteriole and veins in subcutaneous tissue
Capillaries in dermis

Question 13

Cell types of epidermis

Answer 13

Keratinocytes
Langerhans cells
Melanocytes
Merkel cells

Question 14

Function of keratinocytes in epidermis

Answer 14

produce keratin as a protective barrier

Question 15

Function of Langerhans cells in epidermis

Answer 15

present antigens and activate T cells

Question 16

Function of melanocytes in epidermis

Answer 16

produce melanin - protects from UV radiation

Question 17

Function of Merkel cells

Answer 17

contain specialised nerve endings for sensation

Question 18

Common causes of ITCH WITH RASH

Answer 18

Urticaria
Atopic eczema
Psoriasis
Scabies (burrows between fingers)

Question 19

What is urticaria (cause of itch with rash)

Answer 19

Outbreak of swollen, pale red bumps or plaques (wheals) on the skin that appear suddenly -either as a result of the body’s reaction to certain allergens, or for unknown reasons
(Hives, weals, welts)

Question 20

Common causes of ITCH with NO RASH

Answer 20

Renal failure
Jaundice
Iron deficiency
Lymphoma - particularly Hodgkins
Polycythaemia - bath itch
Pregnancy alone
Drugs
Diabetes
Cholestasis
As skin ages it itches more