Skin

Question 1

Layers of the skin
Superior to inferior

Answer 1

Epidermis (90% of the cells are keratinocytes)
Dermis (has blood vessels)
Subcutaneous fat

Question 2

Epidermis layers
Superior to inferior

Answer 2

Stratum corneum
Stratum granulosm
Stratum spinosum
Stratum basale (basement membrane zone)

Question 3

Draw the basement membrane zone

Answer 3

Refer to lecture

Question 4

Describe melanin synthesis

Answer 4

Tyrosine –> Dihydroxyphenylanaline (DOPA) through tyrosine hydroxylase

Dihydroxyphenylanaline to DOPAquione

DOPAquione to eumelanin (brown or black) or phaeomelanin (yellow/red)

Question 5

what is a melanocyte

Answer 5

Keratinocyte with melanosome attached
1 melanocyte to every 10 keratinocytes

Question 6

Vitiligo
common sign?

Answer 6

Autoimmine disease caused by destruction of melanocytes.

A sign is symmeterical neuroectoderm (no melanin)

Question 7

Keratin types and chromosomes they made from

Answer 7

54 types

2 main types:
1. Keratin type 1 (chromosome 17)
2. Keratin type 2 (chromosome 12)

Question 8

Case: 26 year old lady presents with strange toe nails and thickened area on her feet, her daughter has the same issue.
Diagnosis?
other signs?

Answer 8

Pachyonychia congentia
- Autosomal dominant
- Most common mutation: Keratin 6a gene on chromosome 12

Clinically also
Plantar pain, cyst formation and mucosal involment

Question 9

Dermis contains what?

Answer 9

Elastin
Collagen
Vessels
Cells (fibroblasts, macrophages, dermal dendritic cells, mast cells)
Mucopolysacchardies

Question 10

Subcutaneous fat function

Answer 10

Insulation
Energy source
Biologically active (Hormones eg leptin with weight and appetie control)

Question 11

Diagnosis: Inflammed cutaneous fat

Answer 11

Panniculitis

Question 12

Anatomy of nail

Answer 12

Nail plate
Hyponychium
Lateral nail fold
Lunula
Cuticle
Eponychium
Proximal nail fold
Matrix

Question 13

Hair follicle anatomy

Answer 13

hair shaft
Pilosebaceous gland
hair bulb
Papilla
Buldge area
Arrector pilli muscle

Question 14

Inflammation of hair follicle diagnosis

Answer 14

Folliculitis

Question 15

What causes scarring

Answer 15

Deep inflammation and damage to buldge area causes poor healing leading to scarring

Question 16

Eccrine sweat gland:
Neurotransmitter

Answer 16

Acetylcholine

Question 17

Abnormalities of eccrine sweat gland
- treatment options

Answer 17

Hyperhidrosis
Treatment: Ach blocker (anticholinergics) or cut the sympathetic nerve supply (sympathectomy)

Question 18

Whats the piloebaceous unit on the Eccrine sweat gland and can cause …

Answer 18

Section of sweat gland which when gets blocked or bursts causes acne vulgaris

Question 19

Physiological Function of skin

Answer 19

Immune organ
Temperture regulation
Vit D synthesis
Fluid balance
Sensory organ
Protection

Question 20

How does the skin protect us?

Answer 20

1. Trauma
   - tough surface acting as a mechanical layer

2.Microbiome
commensal bacteria acts protective layer against millions of bugs

Question 21

Skins role in immune protection

Answer 21

There are langerhan cells in epidermis,
dermal dendritic cells in dermis and T cells in blood vessels.

If this doesnt function right (ie lacks the barrier function), then it causes issues like atopic eczema

Question 22

Skins role in temperture regulation

Answer 22

Heat and cool through
Shivering
Sweat evaporation
Alteration is cutaneous blood flow

Question 23

Cause of goose bumps

Answer 23

Pillar muscle contracts

Question 24

Vit D synthesis:
Functions

Answer 24

Bone health
Potential role in
cancer, resp disorders, autoimmune diseases, diabetes