Lecture 2: Skin

Question 1

What is Function of Arrector pili muscle?

Answer 1

Contraction produces ‘goosebumps’. Improves insulation

Question 2

What is Function of Root hair plexus?

Answer 2

collection of sensory nerves at the base of each hair follicle. Heightened sensation.

Question 3

What are Sebaceous glands?

Answer 3

Gland’s that Produce oily secretion calledsebum

Question 4

What is the Function of sebum?

Answer 4

• Nourishes hair shaft and naturallymoisturizes the skin.
• Water repellent
• Blocked hair follicles + infectiondue to ↑ sebum production leads
  to acne.

Question 5

Where and what do Eccrine sweat glands do?

Answer 5

• Found in most areas of the skin
• Pour watery secretions directly
  onto the skin surface
• Important in thermoregulation
  and excretion
• Some antibacterial action

Question 6

What and where are Apocrine sweat glands?

Answer 6

• Found in specific areas eg:
  armpit, groin and around the
  nipples
• Secrete sticky/oily and at times,
  potentially odorous secretions
  into the base of the hair follicle
• Influenced by hormones, eg.
  lactation

Question 7

Effects of Skin aging

Answer 7

• Thin epidermis
• Thin dermis
(sagging/wrinkling)
– Reduced collagen
• Impaired cooling (less
sweat)

Question 8

Role of Melanin?

Answer 8

• The melanin pigment
absorbs UV light
– Protecting cells from
UV damage

Question 9

Which cell produces melanin? Where are they found?

Answer 9

• Produced in melanocytes(ie. cells)
• Transferred to epidermal cells by melanosomes (Vesicles containing melanin)
• Melanocytes are only found in the stratum basale – (not shed)

Question 10

What is a Mole?

Answer 10

• Cluster of melanocytes
• Over-proliferation can be
  caused by sun exposure

Question 11

What is a freckle?

Answer 11

-Melanocytes overproducing
melanosomes
-Over-production triggered by
sun exposure

Question 12

What is the role of Vitamin D?

Answer 12

• Essential for calcium metabolism and strong bones
• UV exposure is required for its synthesis

Question 13

What is Basal cell carcinoma?

Answer 13

• Common but relatively benign cancer
• Originates in stratum basale
• Metastasis (spread) is rare

Question 14

What is Malignant melanoma?

Answer 14

• Rare but deadly cancer if not treated
• Originates in melanocytes (pigmented)
• Highly metastatic
• Mortality rate dependent upon tumour size

Question 15

What layer is a tattoo done on?

Answer 15

• Dermal layer
• Pain due to the dermal layer containing nerves and pain receptors