chapter 5 part 2

Question 1

Thick skin

Answer 1

Thick skin (designation refers only to the epidermis)
* Has all 5 epithelial strata.
* Found in areas subject to pressure or friction.
* Palms of hands, fingertips, soles of feet.
* Fingerprints and footprints. Papillae of underlying dermis in parallel rows.

Question 2

thin skin

Answer 2

• Thin skin.
• Composed of 4 strata (no stratum lucidum).
• More flexible than thick skin.
• Covers rest of body.
• Hair grows here.

Question 3

callus

Answer 3

Callus: Increase in number of layers in stratum corneum. When this occurs over a bony prominence, a corn forms

Question 4

Skin color determined by three factors

Answer 4

pigments in the skin, blood circulating
through the skin, thickness of stratum corneum.

Question 5

melanin

Answer 5

skin pigment type
provides for protection against U V light. Group of
chemicals derived from amino acid tyrosine. Colored brown
to black, may be yellowish or reddish.

Question 6

melanocytes

Answer 6

skin pigment type
processes extend between keratinocytes; deposit
melanosomes.

Question 7

Albinism

Answer 7

skin pigment type
deficiency or absence of pigment; production determined by genetics, hormones, exposure to light.

Question 8

carotene

Answer 8

skin pigment type
yellow pigment from vegetables; accumulates in
stratum corneum, in adipose cells of dermis, and in
subcutaneous tissue

Question 9

Melanin Transfer to Keratinocytes steps

Answer 9

1. Melanocytes produce and package melanin into
   vesicles called melanosomes.
2. These melanosomes move into cell processes of the
   melanocytes.
3. Keratinocytes phagocytize the tops of the melanocyte, acquiring melanosomes.

Question 10

Racial variations in skin color due to:

Answer 10

• Types of melanin produced
• Amount of melanin produced
• Size of melanosomes
• Number of melanosomes
• Distribution of melanosomes

Question 11

Cyanosis

Answer 11

blue color caused by decrease in blood oxygen.
(impacted due to the amount of blood circulating)

Question 12

Erythema

Answer 12

red color caused by increased blood flow.
* Thickness of stratum corneum impacts color.
* Thicker areas can be yellowish

Question 13

the most common type of cancer

Answer 13

• Most result from damage from U V radiation that damages the D N A in epidermal cells.
• The amount of melanin affects the likelihood of developing skin cancer; fair-skinned
  people are at a greater risk than dark-skinned people.
• Three major types:
• Basal cell carcinoma
• Squamous cell carcinoma
• Melanoma

Question 14

Basal cell carcinoma

Answer 14

type of skin cancer
* Most common
* Cells of stratum basale
* Varied appearance
* Cured by removal or
destruction

Question 15

Squamous cell carcinoma

Answer 15

• Cells of stratum spinosum
• Varied appearance; may bleed
• Most cases cured by removal
  or destruction

Question 16

Melanoma

Answer 16

• Most deadly
• ABCDE Rule for signs of
  melanoma:
• A – asymmetry
• B – border irregularity
• C – Color not uniform
• D – diameter greater than 6mm
• E – evolving or changing