2. Dermatology

Question 1

Name 6 functions of the skin.

Answer 1

1. Protective barrier against environmental insults, inc. trauma, UV light and pathogens
2. Immunosurveillance
3. Sensation
4. Temperature and fluid regulation
5. VitD synthesis
6. Cosmesis

Question 2

Label.

Answer 2

Question 3

Name the 4 major cell types of the epidermis and state their function.

Answer 3

1. Keratinocytes - protective barrier
2. Langerhans cells (stratum spinosum) - APCs
3. Melanocytes (stratum basale) - melanin protection to protect nuclei from UV DNA damage
4. Merkel cells - mechanoR cells for sensation

Question 4

Describe the 4 layers of the epidermis. Where is an extra layer found?

Answer 4

1. Stratum corneum
2. Stratum granulosum
3. Stratum spinosum
4. Stratum basale - site of keratinocyte mitosis. Cells then move up layers, losing ability to divide.

Stratum lucidum found in areas of thicker skin, e.g. palms and soles.

Question 5

What is the dermis composed of?

Answer 5

Collagen, elastin and glycosaminoglycans - provides strength and elasticity.

Also contains immune cells, nerve cells, skin appendages. lymphatics and blood vessels.

Question 6

What is this condition? Why can it occur and what are the symptoms and consequences?

Answer 6

ERYTHRODERMA = general exfoliative dermatitis with erythema and scaling, involving 90%+ of P’s skin

Most commonly caused by exacerbation of underlying skin condition, e.g. psoriasis or eczema, but can also be caused by drug allergy or cutaneous T cell lymphoma.

Symptoms: pruritis, fatigue, anorexia, cold

Complications:

• hypothermia (loss of thermoregulation)
• infection (loss of protective barrier)
• renal failure (insensible losses)
• cardiac failure (dilated skin vessels)
• protein malnutrition (high skin turnover)