integumentary system + epidermis

Question 1

how many organs are in the integumentary system? name the organ(s).

Answer 1

one. the skin

Question 2

name four of the functions the skin has

Answer 2

1. physical protection against the environment and microorganisms
2. thermoregulation (temperature control)
3. vitamin D production
4. detection of stimuli (touch, temperature, etc)

Question 3

how many layers of skin are there? what are they?

Answer 3

three: epidermis, dermis, hypodermis

Question 4

what is the epidermis?

Answer 4

uppermost layer of the skin

Question 5

what is the dermis?

Answer 5

the layer below the epidermis

Question 6

what is the hypodermis?

Answer 6

a fat layer underneath both the epidermis and dermis

Question 7

where is the dermal papilla located?

Answer 7

between the epidermis and dermis

Question 8

name two things the cells in the dermal papilla does

Answer 8

regenerates hair follicles and is responsible for our finger prints

Question 9

true or false: patterns for the dermal papilla on areas that DO NOT have hair give humans unique ridge patterns (ie. fingerprints)

Answer 9

true

Question 10

how many layers of cells can the epidermis have?

Answer 10

4-5 layers of cells

Question 11

how many layers do areas that contain THIN skin have? where is thin skin found?

Answer 11

4 layers; everywhere except the palms and soles

Question 12

how many layers do areas that contain THICK skin have? where is thick skin found?

Answer 12

5 layers; only found on the palms and soles

Question 13

what is the stratum corneum?

Answer 13

the most superficial layer of cells of the epidermis

Question 14

the stratum corneum has 15-30 layers of _______. these layers are held super tightly by intercellular proteins called __________.

Answer 14

dead keratinocytes; desmosomes

Question 15

what are two functions of the stratum corneum?

Answer 15

creates a water-resistant layer to prevent moisture loss and protects the living parts of the skin from physical, chemical, and UV damage

Question 16

what is the stratum lucidum?

Answer 16

the layer under the stratum corneum

Question 17

true or false: the stratum lucidum is only found in THIN skin

Answer 17

false; the stratum lucidum is only found in THICK skin

Question 18

does the stratum lucidum have a denser or less dense layer of dead keratinocytes compared to the stratum corneum?

Answer 18

the stratum lucidum has a much more dense layer of dense keratinocytes

Question 19

what is a primary function of the stratum lucidum?

Answer 19

it provides a much more protective layer for areas that are prone to more damage

Question 20

where is the stratum granulosum located?

Answer 20

under the stratum lucidum

Question 21

how many layers of keratinocytes does the stratum granulosum have? are they dead or alive?

Answer 21

about 3-5 layers of LIVING keratinocytes

Question 22

the stratum granulosum’s keratinocytes are living, mature, and actively making _______?

Answer 22

keratin

Question 23

what is keratin?

Answer 23

a protein fiber that helps to maintain skin’s elasticity, protects it, strengthens it, and regulates cell growth

Question 24

true or false: the stratum granulosum’s cells are generally flat
if so, what do we call the flat shape?

Answer 24

true; squamous

Question 25

what happens to the cells in the stratum granulosum when they die?

Answer 25

they get pushed into more superficial layers

Question 26

where is the stratum spinosum?

Answer 26

under the stratum granulosum

Question 27

how many layers of keratinocytes does the stratum spinosum consist of? are they dead, immature, mature, or stem cells?

Answer 27

8-10 layers; immature

Question 28

what does it mean to be an immature keratinocyte?

Answer 28

immature keratinocytes are ones that recently differentiated from the deeper layers

Question 29

where are langerhans cells located and what are they responsible for?

Answer 29

located in the stratum spinosum; responsible for the immune response in the skin, it destroys microorganisms and superficial cancer cells

Question 30

what is the deepest layer of the skin in the epidermis? what is it located under?

Answer 30

stratum basale; under the stratum spinosum

Question 31

what type of cells are found in the stratum basale? what do those cells do?

Answer 31

stem cells that differentiate into all the other layers of skin (merkel cells and melanocytes are also found here)

Question 32

where are merkel cells located and what do they do?

Answer 32

located in the stratum basale; responsible for picking up touch stimuli

Question 33

where are melanocytes located and what do they do?

Answer 33

located in the stratum basale; creates melanin to protect skin from UV rays