Chapter 5

Question 1

integument

Answer 1

skin

Question 2

what is the largest organ

Answer 2

skin

Question 3

how large and thick is the skin

Answer 3

22 sq fit, 10-11 lbs, and 0.5-0.6 mm

Question 4

what are the two layers of the skin

Answer 4

epidermis
dermis

Question 5

what is the epidermis

Answer 5

• superficial layer (epithelium of the skin)
• stratified squamous epithelium
• avascular
• keratinized stratified squamous epithelium
• composed of several layers

Question 6

what are layers of the epidermis called

Answer 6

strata

Question 7

what is the dermis

Answer 7

depper layer of areolar and dense irregular connective tissue

Question 8

hypodermis

Answer 8

subcutaneous layer
not a part of the skin, but lies under the dermis and is composed of mostly adipose tissue

Question 9

functions of the integument

Answer 9

• Protection
• Prevention of water loss
• Temperature regulation
• metabolic regulation
• immue defense
• sensory reception
• excretion by means of secretion

Question 10

epidermal strata

Answer 10

• stratum basale
• stratum spinosum
• stratum granulosum
  stratum lucidum (found only in thick skin)
• stratum corneum

Question 11

what is the deepest strata called

Answer 11

stratum basale

Question 12

what is the most superficial layer of state called

Answer 12

stratum corneum

Question 13

stratum basale

Answer 13

• single layer of cells that are capable of mitosis
• the cells that are adjacent to the dermis

Question 14

where do the multiplied cells go

Answer 14

they are pushed up and lose the ability to reproduce

Question 15

what are the cells in the stratum basale

Answer 15

• keratinocytes
• melanocytes
• tactile cells

Question 16

keratinocytes

Answer 16

• most abundant
• produce keratin to protect and waterproof the skin

Question 17

melanocytes

Answer 17

• cells that produce the pigment melanin
• which absorbs UV light to prevent DNA damage

Question 18

tactile cells

Answer 18

cells sensitive to touch

Question 19

stratum spinosum

Answer 19

• several layers thick of the reproduced cells from the stratum basale
• differentiated into nondividing, highly specialized keratinocytes

Question 20

what are the cells present in the stratum spinosum

Answer 20

epidermal dendritic cells

Question 21

epidermal dendritic cells

Answer 21

• immune cells that help fight infection
• phagocytes that initiate an immune response

Question 22

stratum granulosum

Answer 22

• 3-5 layers thick of keratinocytes
• the cytoplasm fills with keratin filaments
• organelles begin to degrade
• fully keratinized cells are dead but strong
• extracellular lipids form epidermal water barrier

Question 23

stratum lucidum

Answer 23

• think, translucent region
• 2-3 layers thick
• present only in thick skin (palms, soles of the feet, places with no hair)

Question 24

descirbe the cells of the stratum lucidum

Answer 24

• lack organelles
• filled with eleidin: transparent, intermediate product of keratin maturation

Question 25

stratum corneum

Answer 25

• most superficial layer of the epidermis
• thickness varies from 20-30 layers depending on person and their activities
• comprised solely of dead keratinocytes

Question 26

keratinization

Answer 26

cells formed on basal accumulate keratin as they are pushed up

Question 27

how long does keratinization take

Answer 27

about 5 weeks for a cell to be formed

Question 28

what does repeated abrasion do to the cells

Answer 28

will cause abnormal development and a thick stratum corneum to form