Epidermis

Question 1

histology

Answer 1

study of the structure and composition of skin tissue

Question 2

physiology

Answer 2

studly of the function of skin tissue

Question 3

6 primary functions

Answer 3

protection, absortion, secretion,sensation, excretion, and regulation of temp.

Question 4

how does the skin protect us?

Answer 4

-melanin-from UV radiation
-acid mantle-protects against bacteria and TEWL
is slightly acidic (5.5-5.6)

Question 5

What is the acid mantle made up of?

Answer 5

sebum, sweat (lactic acid), water and keratohyalin

Question 6

how does the skin regulate temperature?

Answer 6

• perspiration/evaporation to cool the body,

- arrector pili muscles cause goose bumps to trap warmth in.

Question 7

stratum germinativum

Answer 7

• AKA basal layer
• 1 layer
• 70-90% water
• Mitotic
• held together by desmosomes (cell process)
• melanocytes every 10-15 cells (skin color)

Question 8

stratum spinosum

Answer 8

• AKA spiney layer
• 5-8 layers
• 60-70% water
• Keratin production for strength and protection
• Langerhans immune cells to detect and process foreign antigens

Question 9

stratum granulosum

Answer 9

• AKA grainy layer
• 3-5 layers
• 20-60% water
• transitional layer between living and dead cells
• Keratohyalin- an intercellular lipid glue that replaces the desmosomes
• Membrane Coating Granules- make cell 6X stronger

Question 10

stratum lucidum

Answer 10

• AKA clear layer
• 3-5 layers
• 10-20% water
• epidermal ridges that form our fingerprints
• thickest on palms and soles

Question 11

stratum corneum

Answer 11

• AKA horny layer
• 15-20 layers
• 5-10% water
• desquamation occurs which is the skin natural shedding process

Question 12

keratinization process

Answer 12

the 28 day upward migration of skin cells from the stratum germinativum to the stratum corneum

Question 13

basement membrane

Answer 13

• AKA dermo-epidermal junction
• separates the epidermis and dermis
• transports nutrients from the vascular dermis to the -avascular epidermis.

Question 14

melanin

Answer 14

pigment produced by the malanocyte to give us our skin color

Question 15

melanogenesis

Answer 15

-process by which melanin is produced
-the melanosome (an organelle) is stimulated
-It uses tyrosine (amino acid) and tyrosinase (enzyme)
to produce melanin
-melanin is produced and transported from the melanocyte to the surrounding cells

Question 16

3 types of UV rays

Answer 16

UVA
UVB
UVC

Question 17

UVA

Answer 17

• AKA aging ray
• longest ray that penetrates deep into the dermis
• causes damage to collagen and elastin, may lead to cancer

Question 18

UVB

Answer 18

• AKA burning ray
• second longest ray that penetrates into the epidermis
• causes sunburns, premature aging, and may lead to skin cancer

Question 19

UVC

Answer 19

• shortest length

- does not reach the earths surface

Question 20

physical sunscreen

Answer 20

works immediately after application to relect or scatter the suns UV radiation, eg. titanium dioxide, zinc oxide

Question 21

chemical sunscreen

Answer 21

absorbs and traps UV radiation, eg. octinoxate

these are considered over the counter drugs (OTC)