LECTURE 1: anatomy of skin part 1

Question 1

size of skin

Answer 1

• 16% of body weight

- 1.5-2m2 of surface area

Question 2

3 layers of skin

Answer 2

1. Epidermis
2. Dermis
3. Hypodermis

Question 3

Epidermis

Answer 3

stratified barrier, mostly keratinocytes, no circulation (avascular)

Question 4

Dermis

Answer 4

protein fibres for strength (vascular), nourishes epidermis

Question 5

Hypodermis

Answer 5

adipose tissue (insulation) + subcutaneous

Question 6

Cutaneous

Answer 6

epidermis + dermis

Question 7

Subcutaneous

Answer 7

hypodermis

Question 8

Skin anatomy relates to…(4 things)

Answer 8

1. Ageing
2. Pigmentation
3. Skin cancer
4. Tattoo

Question 9

High vs. low pigmentation

Answer 9

High- protection from UV radiation

Low- vitamin D production

Question 10

4 tissue types

Answer 10

1. Epithelial
2. Connective
3. Muscle
4. Nervous

Question 11

Dermis layer has

Answer 11

Papillary layer

Reticular layer

Question 12

Biggest organ in human body

Answer 12

Skin (its most visible too)

Question 13

Stratum corneum layer

Answer 13

I.e. horny layer

- dead, dried out hard cells without nuclei

Question 14

Stratum granulosum layer

granular layer

Answer 14

• Contain granules that promote dehydration of the cell, cross linking of keratin fibres
• Waxy material is secreted into the intercellular spaces

Question 15

Layers of epidermis

Answer 15

• only in thick-skin
  1. Stratum corneum (horny layer)
  2. Stratum granulosum (granular layer)
  3. Stratum spinosum (prickle layer)
  4. Stratum basale (basal layer)

Question 16

Stratum spinosum (prickle layer)

Answer 16

• Intercellular bridges called desmosomes link the cells
  together.
• The cells become increasingly
  flattened as they move upward.

Question 17

Stratum basale (basal layer)

Answer 17

• Columnar (tall) regenerative cells
• As the basal cell divides, a
  daughter cell migrates upwards to replenish the layer above.

Question 18

Strip taping

Answer 18

• Stratum corneum (horny
  layer) can be completely
  removed

Question 19

Which tissue dominates in epidermis

Answer 19

Epithelial

Question 20

Epithelial cell types

Answer 20

SIMPLE: squamous, cuboidal, columnar
STRATIFIED: squamous, cuboidal, columnar (more squished together)

Question 21

Dermis layer

Answer 21

• not shed
• protein fibres for strength (collagen + elastin)
• vascular (nourishes epidermis)

Question 22

Thick skin

Answer 22

• Palms of hands and
  soles of feet
• No hair
• Extra epidermal layer

Question 23

How skin ageing occurs

Answer 23

• Thin epidermis
• Thin dermis (sagging/wrinkling)
• Reduced collagen
• Slower skin repair
• Drier epidermis (less sebum)
• Impaired cooling (less sweat)
• Less pigmentation = pale skin, grey hair

Question 24

Claim about smoking with skin ageing

Answer 24

Smoking increases skin ageing

• “reactive oxygen” damages collagen + elastin
• vasoconstriction (nicotine increases vasopressin