INTEGUMENTARY 1

Question 1

what are the functions of skin

Answer 1

Protection, fight bacteria, prevents water/heat loss

Question 2

what are the two distinct regions of skin

Answer 2

Epidermis: epithelial cells
Dermis: bulk of skin

Question 3

what does the hypodermis do

Answer 3

anchors skin to muscle

Question 4

whats the epidermis

Answer 4

the avascular outermost protective layer thats Made up of epithelial cells

Question 5

what are the four cell types on epidermis

Answer 5

keratinocytes, melanocytes, dendritic cells, tactile epithelial cells

Question 6

what are the five layers on epidermis

Answer 6

stratum basale, spinosum, granulosum, lucidum, corneum

Question 7

give function of keratinocytes, melanocytes, dendritic cells and tactile/merkel cells

Answer 7

Keratinocytes: produce keratin
Melanocytes: produce melanin
Dendritic cells: phagocytes; key immune system activator
Tactile (merkel) cells: sensory receptor for touch

Question 8

what are the most abundant cell types + where do they come from + what are they zipped up by

Answer 8

keratinocytes that come from stratum basal and are zipped up by desmosomes and tight junctions

Question 9

what do keratinocytes produce

Answer 9

keratin - a fibrous protein that gives epidermis its protective abilities

Question 10

how are keratinocytes pushed up/created

Answer 10

Continuously undergo mitosis and are pushed up the layers
Dead, flat sacs once they reach the surface
 Friction increases proliferation
 Hands and feet have increased keratin production

Question 11

why do we have new epidermis every 25-45 days

Answer 11

because of constant regeneration

Question 12

where are melanocytes found

Answer 12

stratum basale

Question 13

what do melanocytes produce

Answer 13

melanin, which is stored in keratinocytes

Question 14

where in the melanocytes is melanin produced

Answer 14

in melanin granule (melanosomes)

Question 15

why do melanocytes cluster on top of skin

Answer 15

because they protect skin from UV radiation

Question 16

order layers from deepest to most superficial

Answer 16

Stratum basale
 Stratum spinosum
 Stratum granulosum
 Stratum lucidum
 Stratum corneum

Question 17

whats the stratum basal? what is it attached to and what does it contain? how much of it is melanocytes

Answer 17

Deepest layer
 Attached to dermis
 10 – 25% of cells are melanocytes
 Consists of single layer of stem cells
» Continuously dividing
» One cell pushed upwards
» Other cell stays in place

Question 18

whats the stratum spinosum

Answer 18

prickly layer thats Several layers thick

Question 19

what do keratinocytes in stratum spinous contain

Answer 19

pre-keratin » Resistant to tension

Question 20

where are dendritic cells most abundant

Answer 20

stratum spinosum

Question 21

whats the stratum granulosum

Answer 21

Thin layer where keratinization begins

Question 22

what happens to cells, nuclei and organelles in stratum granulosum

Answer 22

 Cells flatten, nuclei and organelles degrade,
accumulate granules
» Become tough and water resistant

Question 23

is the stratum granulosum cut off from blood supply

Answer 23

yes

Question 24

describe startum lucidum

Answer 24

Only present in thick skin
 Few layers of dead keratinocytes

Question 25

describe startum corneum

Answer 25

 Thickest and outermost layer
 20 – 30 cell layers thick
 Waterproof
 Shed regularly (dandruff)

Question 26

what do keratinized cells in stratum cornum do

Answer 26

Keratinized cells protect from abrasion and penetration

Question 27

whats the dermis of the skin

Answer 27

“animal hide”
 Bulk of skin
 Made of strong flexible
connective tissue

Question 28

what does the dermis of the skin contain

Answer 28

blood vessels, nerve fibers, lymphatic vessels, and hair follicle

Question 29

what cells are present in the dermis

Answer 29

fibroblasts, macrophages, WBCs

Question 30

what are the two layers in the dermis

Answer 30

papillary and reticular dermis