Intro

Question 1

structure of skin

Answer 1

epidermis, dermis, adnexa, SQ fat

-skin, hair, nails, lips

Question 2

functions of skin

Answer 2

1. decoration/beauty
2. barrier
3. Vit D synthesis
4. water homeostasis
5. thermoregulation
6. insulation/calorie reservoir
7. touch/sensation

Question 3

Fitzpatrick skin types (burn/tan?)

Answer 3

I = always burns
II = easily burns, minimally tans
III = initially burns, gradually tans
IV = minimally burns, tans well 
V = rarely burns, dark tan 
VI = always tans

Question 4

what is the darkness of your skin due to?

Answer 4

Not due to the number of melanocytes in the skin
• Due to the type of melanin produced
– Eumelanin: black to brown pigment
– Pheomelanin: yellow to red-brown pigment
• Due to the distribution melanosomes
– Light Skin: melanosomes distributed in clusters above the nucleus
– Dark Skin: melanosomes distributed individually throughout the cytoplasm

Question 5

stratum basalis (function and cells in the region)

Answer 5

• single layer of columnar or cuboidal cells

- basal keratinocytes (stem cells of the epidermis)

Question 6

stratum spinosum (function and cells in the region)

Answer 6

• desmosome attachments

- synthesis of involuctrin and membrane coating granules

Question 7

stratum granulosum (function and cells in the region)

Answer 7

• cells contain different types of granules

- keratohylin granules contain profilaggrin

Question 8

stratum lucidum (function and cells in the region)

Answer 8

• thin, light staining band (seen only in thick skin)

- cells have no nuclei or organelles

Question 9

stratum corneum (function and cells in the region)

Answer 9

• outermost layer
• keratinocytes are completely filled with keratin
• desmosomes connect tightly packed adjacent cells

Question 10

Hemidesmosomes:

Answer 10

attach basal cells are firmly to the basal lamina of the dermal epidermal junction

Question 11

Desmosomes:

Answer 11

attach keratinocytes to each other

Question 12

Tonofilaments:

Answer 12

protein structures (keratin filaments) that insert into the dense plaques of desmosomes on the cytoplasmic side of the plasma membrane

Question 13

Filaggrin

Answer 13

cross-links keratin tonofilaments and is important in the barrier function of the skin

Question 14

adnexal structures

Answer 14

• Apocrine glands
• Eccrine glands
• Hair
• Nails
• Sebaceous glands

Question 15

thick skin

Answer 15

hairless and found on the palms and soles