Integumtary System: Epidermis

Question 1

Define the Epidermis:

Answer 1

Most superficial layer of skin

Tissue Type: Stratified squamous epithelium

varies in thickness,

Avascular- NO blood vessels

Constantly renewing itself

Question 2

Define the Stratum Corneum layer:

Answer 2

Most superficial layer of the epidermis

Several Layers of horny cells

Contains: flattened dead skin cells + keratin

Constantly shedding of Apical(top) layers as basal cells divide

Question 3

Define Keratinocytes:

Answer 3

Skin cells that produce keratin

Question 4

Define Keratin:

Answer 4

Protein in skin for strength + prevents dehydration

in hair + nails

Question 5

Define the Stratum Lucidum:

“Translucent”

Answer 5

Clear, transparent

Contains: dead karatinocytes + keratin

Only in thick skin on palms + soles of feet

Question 6

Define the Stratum Granulosum:

“Graveyard”

Answer 6

Contains: Dying keratinocytes + keratin

Cells die in this layer

Question 7

Define the Stratum Spinosum:

Answer 7

Contains: Living keratinocytes

Appears “Spiny” due to bundles of keratin proteins

Question 8

Define the Stratum Basale:

Answer 8

Bottom Layer

Contains: Single-raw mitotically active stem cells

Melanocytes- specialized cells that make melanin

Question 9

Define a Stem Cell:

Answer 9

Specialized cell that cna divide continuously into keratinocytes

Question 10

Define Melanin:

Answer 10

Brown, black pigment that protects skin against UV radiation of sun

Amount of melanin present in skin determines for skin tone