Basic anatomy & physiology of skin

Question 1

What does UV damage?

Answer 1

Foliate degradation. Dark skin protects against UV induced foliate degradation.

Question 2

What are the three layers of skin?

Answer 2

Epidermis, Dermis, Subcutaneous fat

Question 3

What are the layers in the epidermis?

Answer 3

Stratum corneum, Stratum granulosum, Stratum spinosum, Stratum basale

Question 4

What anchors keratinocytes to the basement membrane?

Answer 4

Hemidesmosomes

Question 5

Epidermolysis Bullosa

Answer 5

When the epidermal layer is gone and the dermis is left

Question 6

What prevents the body from producing melanin?

Answer 6

Tyrosine Hydroxylase

Question 7

Melanin synthesis pathway

Answer 7

1 Melanocyte : 10 Keratinocyte. Melanocyte contains melanosomes that contain melanin which covers cells and protects them from UV

Question 8

What is vitiligo?

Answer 8

An autoimmune disease caused by the destruction of melanocytes

Question 9

What is keratin?

Answer 9

The protein forming hair, skin and nails

Question 10

What are the contents/functions of the Dermis?

Answer 10

1. Structural and nutritional support
2. Mucopolysaccharides
3. Collagen
4. Elastin
5. Vessels
6. Cells (Fibroblasts, Macrophages, Dermal dendritic cells, Mast cells)

Question 11

What are the functions of subcutaneous fat?

Answer 11

1. Insulation
2. Energy Source
3. Biologically active (Hormones - Leptin [weight and appetite control])

Question 12

What are the structures in the nail?

Answer 12

1. Nail plate
2. Hyponychium
3. Lunula (part of matrix)
4. Matrix (where nail is produced)
5. Eponychium
6. Cuticle
7. Proximal nail fold/Lateral nail fold
8. Nail bed

Question 13

Where does fungal infection of the nail occur?

Answer 13

Usually in the nail plate. Fungal hyphae affects the stratum corneum

Question 14

What are the components in hair?

Answer 14

1. Hair shaft
2. Pilosebaceous gland (produces oily fluid)
3. Hair bulb
4. Papilla
5. Arrector pili muscle
6. Bulge area (contains stem cells)
7. Blood supply (important in temperature regulation)

Question 15

What happens when the bulge area is damaged?

Answer 15

The bulge area contains stem cells and if that area is damaged, there will be poorer healing causing scarring

Question 16

Eccrine sweat gland

Answer 16

Found deep in the dermis and is controlled by the sympathetic nervous system

Question 17

What are the treatments for excessive sweating?

Answer 17

1. Using anticholinergics to block the neurotransmitter acetylcholine
2. Cut the sympathetic nerve supply to that area (Sympathectomy)

Question 18

What causes acne?

Answer 18

The rupturing of the pilosebaceous duct

Question 19

What are the physiological functions of the skin?

Answer 19

1. Acts as an immune organ
2. Involved in temperature regulation
3. Vitamin D synthesis
4. Fluid balance
5. Sensory organ
6. Protection (against the external environment/trauma)