integumentary system

Question 1

what are the 2 distinct layers

Answer 1

• epidermis

- dermis

Question 2

what type of epithelium is the epidermis

Answer 2

keratinized, stratified squamous epithelium

Question 3

what are the 3 types of cells that occupy the stratum basale

Answer 3

• keratinocytes
• melanocytes
• tactile cells

Question 4

what is keratin

Answer 4

a tough and insoluble protein that strengthens the epidermis

Question 5

what are the keratin proteins found in keratinocytes called

Answer 5

cytokeratins

Question 6

what is the most abundant cell type in epidermis

Answer 6

keratinocytes

Question 7

what are the functions of melanocytes

Answer 7

produce and store the pigment melanin in response to UV light

Question 8

what are the granules in which cytoplasmic pigment transfer occurs in called

Answer 8

melanosomes

Question 9

what 4 colours can the pigment of melanocytes appear

Answer 9

• black
• brown
• tan
• yellow-brown

Question 10

how does pigment protect keratinocyte DNA

Answer 10

the pigment accumulates around the nucleus of the keratinocyte which shields the nuclear DNA from UV radiation

Question 11

what does blocking UV light achieve

Answer 11

preventing mutations in keratinocyte DNA (in epidermis) and fibroblasts (dermis)

Question 12

what is tactile cells also known as

Answer 12

merkel cells

Question 13

where can tactile cells be found

Answer 13

scattered among the cells in the stratum basale

Question 14

what do tactile cells do in response to touch

Answer 14

release chemicals that stimulate sensory nerve endings, providing info about objects touching the skin

Question 15

in order of superficial to deep, what are the 5 layers of the epidermal strata

Answer 15

• stratum corneum
• stratum lucidum
• stratum granulosum
• stratum spinosum
• stratum basale

Question 16

what are the 3 strata which are composed of living keratinocytes

Answer 16

• stratum basale
• stratum spinosum
• stratum granulosum

Question 17

what forms the stratum spinosum

Answer 17

several layers of polygonal keratinocytes

Question 18

what happens when a stem cell divides in the stratum basale

Answer 18

• a daughter cell is pushed to the stratum spinosum and begins to differentiate into a non-dividing, highly-specialized keratinocyte
• the other daughter cell remains in the stratum basale

Question 19

what are desmosomes

Answer 19

membrane junctions which keratinocytes in the stratum spinosum use to attach to their neighbours

Question 20

what’s the other cell is found in the stratum spinosum

Answer 20

epidermal dendritic cells (langerhans)

Question 21

where can epidermal dendritic cells be located

Answer 21

in the stratum spinosum and granulosum

Question 22

how many layers of keratinocytes is the stratum granulosum consisting of

Answer 22

3 to 5

Question 23

what process begins in stratum granulosum

Answer 23

keratinization

Question 24

describe the process of keratinization

Answer 24

keratinocytes fill up with the protein, keratin which causes the cell’s nucleus and organelles to disintegrate so the cell dies

Question 25

when is keratinization complete

Answer 25

when the keratinocytes reach the more superficial epidermal layers

Question 26

how many layers of keratinocytes are there in stratum lucidum

Answer 26

2 to 3

Question 27

where is stratum lucidum found

Answer 27

thick skin

Question 28

description of keratinocytes in stratum lucidum

Answer 28

flattened, pale cells

Question 29

what translucent protein are keratinocytes filled with in the stratum lucidum

Answer 29

eleiden

Question 30

where is eleiden produced

Answer 30

it’s an intermediate product of the process of keratin maturation

Question 31

what does thick skin contain

Answer 31

sweat glands

Question 32

what does thick skin not contain

Answer 32

hair follicles or sebaceous (oil) glands

Question 33

what tissue is the papillary layer composed of

Answer 33

areolar connective tissue

Question 34

what are the projections of the dermis called

Answer 34

dermal papillae

Question 35

what do the epidermal ridges and dermal papillae do together

Answer 35

they increase the area of contact between 2 layers and interlock them

Question 36

what do the capillaries in the dermal papillae do

Answer 36

supply nutrients to the cells of the epidermis

Question 37

what connective tissue is the reticular layer consisting of

Answer 37

dense irregular connective tissue

Question 38

how are collagen fibers structured in the reticular layer of the dermis

Answer 38

they are interwoven into a meshwork that surrounds structures in the dermis

Question 39

how are collagen and elastic fibers in the skin oriented

Answer 39

in parallel bundles at specific body locations

Question 40

what do the lines of cleavage do

Answer 40

identify the predominant orientation of collagen fiber bundles

Question 41

what is the hypodermis

Answer 41

subcutaneous layer

Question 42

what does the subcutaneous layer consist of

Answer 42

areolar connective tissue and adipose connective tissue

Question 43

functions of the integument (7)

Answer 43

• protection
• prevention of water loss and water gain
• metabolic regulation
• secretion and absorption
• immune function
• temperature regulation
• sensory reception

Question 44

what are the 3 types of epidermal derivatives

Answer 44

• nails
• hair
• exocrine glands

Question 45

what are the 3 parts which form the nail plate

Answer 45

• free edge
• nail body
• nail root

Question 46

what does the nail body cover

Answer 46

• a layer of epidermis called the nail bed

Question 47

what are the 3 types of hair

Answer 47

• lanugo
• vellus
• terminal

Question 48

what stimulates to ‘raise hair’

Answer 48

arrector pili

Question 49

4 functions of hair

Answer 49

• protection
• heat retention
• sensory reception
• visual identification

Question 50

what are the 2 most common types of exocrine glands

Answer 50

• sweat glands

- sebaceous glands